CN118772656A - Composite Systems - Google Patents

Abstract

A composite material includes a polymer and a graphene-containing material. The polymer comprises a filler configured to distribute one or more stress concentration regions of the composite over one or more corresponding larger regions of the composite. The graphene-containing material may be at least partially mixed into the polymer in one or more exposed surfaces of the polymer based on the folds of the graphene-containing material. In some embodiments, the corrugations may increase the bonding between the polymer and the graphene-containing material. In some cases, the filler may comprise a plurality of carbon fiber layers that are intersected by an organometallic material to form a matrix configured to strengthen the interconnection of the composite.

Description

Composite Systems

This application is a divisional application of the invention application with an application date of January 26, 2021, an international application number of PCT/US2021/015098, a Chinese national phase application number of 202180016953.5, and an invention name of "Composite Material System".

Technical Field

The present disclosure relates to techniques for making and using composite materials systems containing carbon and polymers.

Background Art

Composite materials are often formed by mixing carbon materials and sometimes fibers with polymer resins to enhance the properties of the formed composite material, such as enhancing mechanical, electrical and other properties. For example, carbon can be used as a reinforcement to provide high tensile strength to the formed composite material while being lightweight. In another example, carbon can be used to increase the conductivity of an otherwise non-conductive polymer.

Methods for improving the properties of polymer composites have been extensively studied. Mixing techniques such as solution mixing and melt processing and related parameters such as solvent type and different viscosities have been studied to improve the uniformity of dispersion of carbon materials in resins. Alignment of carbon fibers and CNTs within polymer melts and the effect of alignment on the resulting properties of the formed composites have also been studied. Chemical techniques for functionalizing carbon have been used in attempts to increase the bonding interactions between carbon and polymers.

The carbon that has been used to date is the following carbon: (1) graphene sheets or graphene-like carbon structures or (2) graphite particles or graphite-derived particles.

Unfortunately, graphene sheets or graphene-like carbon structures do not provide sufficient active sites for functionalization and bonding to polymers, and unfortunately, graphite particles or graphite-derived particles do not provide sufficient surface area for bonding to polymers.

What is needed is a method of making carbon structures that exhibit high surface area as well as high active area. What is needed is a method of making and using carbon that exhibits morphology other than graphene sheets or graphite particles.

Summary of the invention

The method includes: producing a regulating carbon structure in a plasma reactor and/or other reactor; and combining the regulating carbon structure with a polymer to form a composite material. The regulating carbon structure includes wrinkled graphene. The method also includes functionalizing the regulating carbon structure in situ in the plasma reactor, in a liquid collection facility, or in another post-processing facility. The plasma reactor has: a first control for adjusting the specific surface area of the resulting regulating carbon structure; and an independent second control for adjusting the specific active area of the regulating carbon structure. The composite material obtained by mixing the regulating carbon structure with the polymer produces a composite material that exhibits excellent mechanical properties. The physical and chemical mechanisms that operate between the wrinkled graphene and the polymer are responsible for these excellent mechanical properties.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings described below are for illustration purposes only. The drawings are not intended to limit the scope of the present disclosure.

1A-1B show schematic diagrams of plasma reactors according to some embodiments.

FIG. 2 shows a schematic diagram of forming a composite material with graphene nanosheets as known in the art.

FIG. 3A shows a schematic diagram of a 3D graphene particle according to some embodiments.

FIG. 3B shows a schematic diagram of a composite material of 3D graphene and polymer according to some embodiments.

4A-4E show scanning electron microscope (SEM) images of a combination of a carbon material and a resin according to some embodiments.

5A-5B show schematic diagrams of fibers for incorporation into carbon-resin composites according to some embodiments.

6 shows a schematic diagram of carbon material grown on fibers according to some embodiments.

7A-7D show SEM images of carbon material grown onto fibers according to some embodiments.

8A-8B show images illustrating functionalized carbon materials according to some embodiments.

9 shows a schematic diagram of a field enhancement waveguide according to some embodiments.

10A-10B show schematic diagrams of adding energy to a composite material according to some embodiments.

11A-11B show schematic diagrams of carbon materials with engineered defects according to some embodiments.

12 shows a flow chart of a method for producing a composite material, according to some embodiments.

13 shows a flow chart of a method for producing a composite material according to some embodiments.

14 shows a schematic diagram of the bonding of metal to carbon of a composite material according to some embodiments.

FIG. 15 shows the results of using structured impurity-free carbon according to some embodiments.

16A shows a graph relating the specific active area of carbon to a given specific surface area, according to some embodiments.

16B1 depicts a system for synthesizing 3D carbon tuned to correspond to a desired morphology, according to some embodiments.

Figure 16B2 shows a reactor with a set of independently variable multi-parameter controls according to some embodiments.

FIG. 16B3 shows a morphology selection technique implemented through multi-parameter control according to some embodiments.

16B4 shows a schematic diagram of the morphology of a corrugated sheet composed of flat crystallites of various lengths (La ₁ , La ₂ , etc.) that are fused together at the folds of the sheet, according to some embodiments.

16C1 shows the D:G intensity ratio of the D and G bands in Raman spectra measured for several wrinkle morphologies compared to a reference according to some embodiments.

16C2 shows the 2D:G intensity ratio of the 2D band and the G band in the Raman spectra measured for several wrinkle morphologies compared to a reference according to some embodiments.

17A shows a process flow for processing carbon material from a reactor and delivering the composite material for downstream processing, according to some embodiments.

FIG. 17B shows how the polymer chains and carbon structures interact when subjected to shear input and cooling.

18A and 18B show DMA analysis of samples of composite materials made with conditioning carbon in comparison to reference composite materials, according to some embodiments.

FIG. 18C1 shows the improvement in compressive strength and flexural strength relative to a reference according to some embodiments.

FIG. 18C2 shows the improvement in interlaminar shear strength and flexural strength relative to a reference sample according to some embodiments.

19A shows the improvement in mechanical characteristics of a thermoplastic material sample associated with the selection of carbon having a particular fractal dimension, according to some embodiments.

19B1 shows that flexural modulus improves with increasing carbon loading volume according to some embodiments.

FIG. 19B2 shows that flexural strength improves with increasing carbon loading volume according to some embodiments.

19C shows the improvement in tensile strength relative to a reference sample when using carbon of the present disclosure, according to some embodiments.

20 shows a system for producing carbons of specified morphologies and using them in composite systems, according to some embodiments.

21 depicts various properties of thermoplastic and thermoset materials used in the illustrated application, according to some embodiments.

DETAILED DESCRIPTION

Overview

Embodiments of the present invention disclose a method for manufacturing a carbon-resin composite material by using a unique plasma reactor to produce a unique carbon material and functionalizing it. The present disclosure describes the form of carbon to be used in the composite material, the method for manufacturing carbon (including forming the carbon material and functionalizing the carbon material), and the method for manufacturing the carbon-resin composite material. The carbon material is incorporated into the composite material mixture for customizing material properties, such as flexural modulus, tensile strength, compression modulus, fracture toughness, and interlaminar shear strength. The configuration and concentration of these unique carbon additives can be adjusted to provide a final composite material with desired properties. For example, the composite material can be customized to have high strength and rigidity or be semi-flexible. In another example, the composite material can be adjusted to have a high modulus when minimal torsion and damage relaxation are required.

Embodiments include methods for in-situ generation and treatment of carbon materials for composite material generation in plasma reactors, which make streamlined processes possible and reduce the need for wet chemical techniques compared to conventional methods. In some embodiments, the carbon material is produced by a hydrocarbon cracking process in a microwave plasma reactor. Embodiments may include additional reactor technologies combined with plasma reactors, such as thermal reactors. In some cases, the carbon material produced is also functionalized to be compatible with resins during the functionalization process, and the functionalization process occurs in the same plasma reactor as for producing the carbon material. In some embodiments, the carbon material produced is a particle with or without functionalization, which can be combined with a resin in a reactor to form a composite material. Carbon particles used as the starting material of the composite material of the present invention may include graphene, spherical carbon (carbon nano onion (CNO), which may also be referred to as multi-walled spherical fullerene (MWSF) or multi-shell fullerene) and/or carbon nanotubes (CNT). The carbon particles may have a unique three-dimensional (3D) structure in the X, Y and Z dimensions, such as a graphene structure that forms a porous matrix (such as void space, cavity or opening) and includes sub-particles of single-layer graphene (SLG), few-layer graphene (FLG) and/or multi-layer graphene (MLG). The porous matrix and high surface area of the 3D structure of the present invention enhance the interlocking of the resin and the carbon material, improve the interfacial strength and adhesion between the resin and the carbon material, and thus improve the properties of the resulting composite material.

In some embodiments, due to the functionalization of the 3D structure of the carbon material and/or the carbon particles, the carbon particles are well dispersed and highly integrated with the resin. For example, before being combined with the resin, the starting material in various embodiments can be functionalized in a reactor, such as by chemical doping of the carbon particles (such as, using sulfur or metal) or by connecting functional groups (such as, COOH, OH, epoxy groups, etc.) and maintaining a specific environment inside and around the material to ensure and promote carbon-polymer bonding. Functionalization can promote the bonding of carbon particles to the resin via chemical bonding (such as covalent bonding or ionic bonding), physical bonding (such as hydrogen bonding and/or π-π bonding), friction or a combination thereof. The reaction conditions and processes of the covalent functionalization method are more difficult to achieve than physical and non-covalent bonding methods, but due to the strong need for the stability of the functional graphene obtained by doping and covalent bonding methods, complexity is necessary.

The carbon particles in various embodiments may initially be supplied to the composite material in nano- to micron-sized aggregates. In some embodiments, the carbon aggregates or particles are broken into smaller particle sizes while mixing with the resin, wherein the newly exposed carbon surfaces from the breaking of the particles provide enhanced bonding to the resin compared to the surfaces exposed to the surrounding (non-resin) environment prior to combination with the resin. In some embodiments, the carbon particles may be engineered to have defects to control the fracture locations and the size of the fragmented particles, thus providing customization of the composite material properties.

The embodiment of the composite material of the present invention can be any polymer system with carbon material of the present invention and optionally with fiber reinforcement. In some embodiments, fiber (such as carbon composite filler (CCF) or non-CCF material) is added to the composite material. The reinforcement provided by the composite material of the present invention includes, for example, the toughness increased compared with conventional composite materials and moldable carbon materials (with or without non-CCF or CCF additives). Carbon material increases the value of CCF composite materials by providing a stronger, tougher, customizable modulus (such as rigidity to flexibility) compared with conventional CCF composite materials and by providing injectable carbon matrix materials. In some embodiments, in addition to carbon particle additives, fiber is also used as reinforcing material, and provides adjustable to adjust composite material properties (such as, to form carbon-resin composite materials with anisotropic material properties) additional parameters. In some embodiments, fiber is introduced into the reactor to provide a site for the growth of carbon particle additives, thereby forming an integrated 3D structure for use in combination with resin.

Carbon-resin composite materials and methods for manufacturing composite materials disclosed herein provide many benefits. Some embodiments make it possible for higher strength composite materials (such as toughening resins that can control plasticity to elastic behavior) with improved quality. In some embodiments, high strength can be achieved without increasing the viscosity of uncured polymer-carbon mixtures, which is in contrast to conventional composite materials, in which higher reinforcements generally result in products with higher filler loads, and therefore result in higher viscosity of uncured polymer-carbon mixtures. In some embodiments, the methods and materials of the present invention also make it possible to adjustability, such as the ability to manufacture specific carbon structures or skeletons to chemically bond other materials or elements to carbon, or such as the ability to provide specific orientation of carbon particles relative to polymer chains in resin structures. Some embodiments make it possible to engineer fracture surfaces into carbon materials to achieve the ability of stress band orientation, produce final standard particle size, and also make it possible to customize composite materials. In some embodiments, 3D structured carbon materials provide 3D growth networks, which produce excellent carbon-polymer bonding.

The 3D carbon material produced by the method of the present invention can make it possible to improve the properties of composite materials. In one example, the modification of energy transfer (that is, the distribution of the force or stress of the resin, fiber and carbon particles in the composite matrix) is realized in the fiber reinforced composite material system. In other words, stress/energy transfer is allowed to spread in a wider area/volume, and can be spread in several reinforced fiber plies or larger polymer regions. In another example, the energy dissipation in the system is controlled to alleviate or concentrate, such as by engineering the structure to realize the movement of energy in or along the specified surface. In another example, crack propagation is alleviated by the stress termination realized by the carbon material of the present invention. Toughening resins can also be prepared, wherein plasticity to elastic behavior can be controlled. In some embodiments, high strength can be realized without increasing viscosity. It is opposite to the behavior of conventional composite materials caused by higher viscosity with higher enhancement.

Resin materials that can be combined with carbon to make the composite materials of the present disclosure include, but are not limited to, thermosets, thermoplastics, polyesters, vinyl esters, polysulfones, epoxies (including high viscosity epoxies such as novolacs or other epoxies), rigid amines, polyimides, and other polymer systems, or combinations thereof.

In the present disclosure, the combined carbon and resin composites may be referred to as "carbon-resin composites", "carbon-polymer composites", "composite materials", "composite systems", "matrix resins" or "composite materials". The terms "resin", "polymer" and "binder" shall be used interchangeably with respect to materials that are combined with one type of carbon to form the composite in an uncatalyzed or pre-catalyzed state. The carbon particles mixed with the resin may be referred to as "starting particles", "added carbon particles", "carbon additives" or "fillers". The terms "voids", "void spaces", "pores" or "pore matrix" shall be used interchangeably to refer to the spaces, cavities or openings within and around the carbon, which may be through-holes or closed-end spaces, and form a continuous and/or discontinuous porous network or matrix.

Types of resin systems that can be combined with carbon to form the composite materials of the present invention include: resins, where a crosslinker or hardener is used to cure the composite system; two-part systems, where a first material is mixed with a second material as a hardener; and thermoplastic materials, which are above the glass transition temperature when the carbon is added. In some embodiments, the carbon material of the present invention is functionalized with a first material and then added to a second material, so that the carbon is used as a vehicle for adding the first material to the second material (where one material can be a resin and the other can be a catalyst and/or a crosslinker). In addition, the carbon particles can have a resin and/or a hardener surrounding them or bonded to them, and the carbon particles can be supplied to missing or additional components to make a complete final composite system.

In the present disclosure, the term "graphene" refers to an allotrope of carbon in the form of a two-dimensional atomic-scale hexagonal lattice, in which one atom forms each vertex. The carbon atoms in graphene are mainly sp2-bonded. In addition, the Raman spectrum of graphene has three main peaks: a G mode at about 1580cm-1, a D mode at about 1350cm-1, and a 2D mode peak at about 2690cm-1 (when using a 532nm excitation laser). In the present disclosure, a single-layer graphene is a single hexagonally arranged (such as, mainly sp2-bonded) carbon atom sheet. It is known that the intensity ratio of the 2D mode peak to the G mode peak (such as, 2D/G intensity ratio) is related to the number of layers in graphene. A higher 2D/G intensity ratio corresponds to fewer layers in a multilayer graphene material. In different embodiments of the present disclosure, graphene contains less than 15 carbon atom layers, or less than 10 carbon atom layers, or less than 7 carbon atom layers, or less than 5 carbon atom layers, or less than 3 carbon atom layers, or contains a single carbon atom layer, or contains 1 to 10 carbon atom layers, or contains 1 to 7 carbon atom layers, or contains 1 to 5 carbon atom layers. In some embodiments, few-layer graphene (FLG) contains 2 to 7 carbon atom layers. In some embodiments, multi-layer graphene (MLG) contains 7 to 15 carbon atom layers.

In the present disclosure, the term "graphite" refers to an allotrope of carbon in the form of a two-dimensional atomic-scale hexagonal lattice, in which one atom forms each vertex. The carbon atoms in graphite are mainly sp2-bonded. In addition, the Raman spectrum of graphite has two main peaks: a G mode at about 1580cm-1 and a D mode at about 1350cm-1 (when using a 532nm excitation laser). Similar to graphene, graphite contains hexagonally arranged (such as, mainly sp2-bonded) carbon atom layers. In different embodiments of the present disclosure, graphite may contain more than 15 carbon atom layers, or more than 10 carbon atom layers, or more than 7 carbon atom layers, or more than 5 carbon atom layers, or more than 3 carbon atom layers.

In the present disclosure, the term "fullerene" refers to an allotrope of carbon in the form of a hollow sphere, ellipsoid, tube or other shape. Spherical fullerenes may also be referred to as Buckminsterfullerenes or buckyballs. Cylindrical fullerenes may also be referred to as carbon nanotubes. Fullerenes are chemically similar to graphite, which consists of stacked graphene sheets of connected hexagonal rings. Fullerenes may also contain pentagonal (or sometimes heptagonal) rings.

In the present disclosure, the term "multi-walled fullerene" refers to a fullerene having multiple concentric layers. For example, a multi-walled nanotube (MWNT) contains multiple rolled graphene layers (concentric tubes). Multi-walled spherical fullerene (MWSF) may also be referred to as multi-shell fullerene (MSF), containing multiple concentric fullerene spheres.

In the present disclosure, the term "particle" refers to a plurality of sub-particles or nanoparticles connected together by carbon-carbon bonds, van der Waals forces, covalent bonds, ionic bonds, metallic bonds or other physical or chemical interactions. Particles can also be referred to as aggregates, and the size can vary greatly, but is generally greater than about 500nm, and is composed of a subset of particles (such as primary particles). Throughout the present disclosure, the term "particle" is a general term that can include particles of any size. Sub-particles can include one or more types of structures (such as crystal structures, defect concentrations, etc.) and one or more types of atoms. Sub-particles can be in any shape, including but not limited to spherical, spherical, dumbbell-shaped, cylindrical, elongated cylindrical, rectangular prism, disc-shaped, linear, irregular, dense shape (such as, with very few gaps), porous shape (such as, with many gaps), etc.

Microwave Reactor

The methods of embodiments of the present invention utilize a unique plasma reactor that is capable of producing carbon particles, modifying the carbon particles to be compatible with resins, and combining the carbon with the resin, all in the same reactor during the process of producing the carbon particles. Although microwave energy shall be used as an example to describe the embodiments, the present disclosure is generally applicable to high frequency plasma reactors that utilize radio frequencies and frequency bands such as very high frequencies (VHF, 30 MHz to 300 MHz), ultra-high frequencies (UHF, 300 MHz to 3 GHz), or microwave frequencies (such as 915 MHz or higher, such as 2.45 GHz or 5.8 GHz). In addition, although the embodiments shall be described primarily with respect to plasma reactors, the methods of the present invention may include the use of other reactor technologies (such as thermal reactors) in conjunction with plasma reactors.

In some embodiments, the carbon materials of the present invention are produced using a microwave plasma reactor and/or method as described in U.S. Pat. No. 9,812,295, entitled “Microwave Chemical Processing,” or U.S. Pat. No. 9,767,992, entitled “Microwave Chemical Processing Reactor,” which are assigned to the same assignee as the present application and are incorporated herein by reference as if fully set forth herein for all purposes.

In some embodiments, microwave plasma chemical treatment of process precursor materials (such as hydrocarbon gas or liquid mixture) is used to produce carbon particles, sub-particles (such as nanoparticles) and aggregates described herein. More specifically, microwave plasma chemical treatment of precursor materials using various techniques (including microwave radiation pulses that control the energy of plasma) can be used to produce carbon particles and sub-particles described herein. The ability to control plasma energy enables one or more reaction pathways to be selected when the precursor material is converted into a specific separation component. Pulsed microwave radiation can be used to control the energy of the plasma because the short-lived high-energy substances produced when the plasma is ignited can be regenerated at the beginning of each new pulse. The plasma energy is controlled to have an average ion energy lower than conventional techniques, but the level is high enough to enable the target chemical reaction to occur at high precursor material flow and high pressure. In some embodiments, the pressure in the waveguide is at least 0.1 atmospheres.

In some embodiments, the processing material is a gas. In some embodiments, the processing material is a hydrocarbon gas, such as C2H2, C2H4, C2H6. In some embodiments, the processing material is methane, and the separated components are hydrogen and carbon nanoparticles. In some embodiments, the processing material is carbon dioxide with water, and the separated components are oxygen, carbon and water.

The microwave reactor used in the embodiments of the present invention may utilize a "field enhanced waveguide" (FEWG), which refers to a waveguide having a first cross-sectional area and a second cross-sectional area, wherein the second cross-sectional area is smaller than the first cross-sectional area and is further away from the microwave energy source than the first cross-sectional area. The reduction in cross-sectional area enhances the field by concentrating microwave energy, wherein the size of the waveguide is set to maintain the propagation of the specific microwave frequency used. The second cross-sectional area of the FEWG extends along the reaction length of the reaction zone forming the FEWG. There is a field enhancement zone between the first cross-sectional area and the second cross-sectional area of the FEWG. That is, in some embodiments, the field enhancement zone of the FEWG has a reduced cross-sectional area between the first cross-sectional area and the second cross-sectional area of the field enhancement waveguide, wherein the second cross-sectional area is smaller than the first cross-sectional area. The reaction zone is formed by the second cross-sectional area extending along the reaction length of the field enhancement waveguide. The microwave energy source is coupled to the field enhancement waveguide, and microwave energy is provided to the first cross-sectional area of the field enhancement zone, wherein the microwave energy propagates in the direction of the reaction length along the reaction zone. There is no dielectric barrier between the field enhancement zone and the reaction zone in the microwave plasma reactor.

Definitions and use of drawings

For ease of reference, some of the terms used in this specification are defined as follows. The terms presented and their respective definitions are not strictly limited to these definitions, and the terms can be further defined by the use of the terms in this disclosure. The term "exemplary" is used herein to mean serving as an example, an example or an illustration. Any aspect or design described herein as "exemplary" is not necessarily understood to be preferred or advantageous compared to other aspects or designs. On the contrary, the use of the word exemplary is to present the concept in a specific manner. As used in this application and the appended claims, the term "or" is intended to mean including "or" rather than exclusive "or". That is, unless otherwise specified or clear from the context, "X adopts A or B" is intended to mean any natural inclusive arrangement. That is, if X adopts A, X adopts B, or X adopts both A and B, then "X adopts A or B" satisfies under any of the aforementioned examples. As used herein, at least one of A or B means at least one of A, or at least one of B, or at least one of A and B. In other words, this phrase is disjunctive. As used in this application and the appended claims, the articles "a" and "an" should generally be understood to mean "one or more" unless specified otherwise or clear from context to be directed to a singular form.

Various embodiments are described herein with reference to the accompanying drawings. It should be noted that the drawings are not necessarily drawn to scale, and elements of similar structure or function are sometimes represented by similar reference numerals throughout the drawings. It should also be noted that the drawings are intended only to facilitate the description of the disclosed embodiments, they do not represent an exhaustive treatment of all possible embodiments, and they are not intended to place any limitations on the scope of the claims. In addition, the illustrated embodiments do not necessarily describe all aspects or advantages of use in any specific environment.

An aspect or advantage described in conjunction with a specific embodiment is not necessarily limited to that embodiment and may be practiced in any other embodiment even if not so described. References throughout this specification to "some embodiments" or "other embodiments" mean that a specific feature, structure, material, or feature described in conjunction with the embodiment is included in at least one embodiment. Therefore, the appearance of the phrase "in some embodiments" or "in other embodiments" in various places throughout this specification does not necessarily refer to the same embodiment or embodiments. The disclosed embodiments are not intended to limit the claims.

Description of Exemplary Embodiments

FIG. 1A and FIG. 1B show an embodiment of a microwave chemical processing system of the present disclosure, wherein a FEWG is coupled to a microwave energy generator (such as a microwave energy source), a plasma is generated from a supply gas in a plasma zone of the FEWG, and a reaction length of the FEWG is used as a reaction zone for separating the treated material into separate components. The reactor of the present invention as shown in FIG. 1A and FIG. 1B does not have a dielectric barrier between the field enhancement zone and the reaction zone of the field enhancement waveguide. The absence of a dielectric barrier in the reactor of the present invention advantageously allows microwave energy to be directly transferred to the input material being processed (such as a hydrocarbon gas), achieving a processing temperature higher than that of a conventional reactor (such as 3000K and above), and particularly very high local temperatures (such as 10,000K and above). In contrast, the reaction zone of a conventional system is enclosed in a dielectric barrier such as a quartz chamber. Therefore, microwave energy is used for indirect heating, for ionizing a carrier gas into a plasma, but the microwave energy itself is not transmitted through the barrier. The propagation direction of the microwave energy is parallel to most of the supply gas and/or treated material flow, and the microwave energy enters the waveguide upstream of the portion of the FEWG where the separated components are produced.

As shown in FIG. 1A , according to some embodiments, a microwave chemical processing reactor generally includes: a FEWG 205; one or more inlets 202 configured to receive a supply gas and/or a processing material 208a flowing into the FEWG 205; and a microwave energy source 204 coupled to the FEWG 205; and other components not shown for simplicity. In some embodiments, a microwave circuit 207 controls a pulse frequency when pulsing microwave energy 209 from the microwave energy source 204. In some embodiments, the microwave energy 209 from the microwave energy source 204 is a continuous wave.

FEWG 205 has a length L. The portion of FEWG 205 having a length LA (shown in FIGS. 1A and 1B ) is closer to the microwave energy generator than the portion of the FEWG having a length LB (shown in FIGS. 1A and 1B ). Throughout this disclosure, different portions of the FEWG will be described by capital letters L, with the subscripts representing a portion of the FEWG (such as LA, L0, LB, L1, L2), and synonymously, the lengths of different portions of the FEWG will also be described by capital letters L, with the subscripts representing the lengths of a portion of the FEWG (such as LA, L0, LB, L1, L2).

The cross-sectional area of the FEWG in the length LB is less than the cross-sectional area of the FEWG in the length LA. The length of the FEWG L0 is located between the lengths LA and LB of the FEWG and has a cross-sectional area that decreases along the path of microwave energy propagation. In some embodiments, the cross-sectional area of the FEWG along the length L0 decreases in a continuous manner. In some embodiments, the cross-sectional area of the FEWG along the length L0 decreases linearly between the lengths LA and LB. In some embodiments, the cross-sectional area of the FEWG along the length L0 decreases nonlinearly between the lengths LA and LB, such as in a parabolic manner, in a hyperbolic manner, in an exponential manner, or in a logarithmic manner. In some embodiments, the cross-sectional area of the FEWG along the length L0 decreases in a sudden manner between the lengths LA and LB, such as by one or more discrete steps. The reduction in cross-sectional area is used to concentrate the electric field, thereby increasing the microwave energy density while still providing a large area in which plasma can be formed compared to conventional systems.

When using a microwave energy frequency of 2.45 GHz, the portion of the FEWG having a length LB (shown in FIGS. 1A and 1B ) may have a rectangular cross-section with dimensions of 0.75 inches by 3.4 inches. This cross-sectional area is much larger than conventional systems, where the plasma generation area is typically less than one square inch. The dimensions of the different portions of the FEWG 205 are set according to the microwave frequency in order to function properly as a waveguide. For example, for an elliptical waveguide, the cross-sectional dimensions may be 5.02 inches by 2.83 inches for 2.1-2.7 GHz.

In conventional gas processing systems, the limited area in which plasma can be formed (such as, less than one square inch as described above) limits the volume in which gas reactions can occur. Moreover, in conventional systems, microwave energy enters the reaction chamber through a window (usually quartz). In these systems, dielectric materials (such as carbon particles) are coated on the window during processing, causing power delivery to decrease over time. If these separate components absorb microwave energy, this can be very problematic because they can prevent microwave energy from coupling to the reaction chamber to produce plasma. As a result, rapid accumulation of byproducts (such as carbon particles produced by gas reactions) occurs and limits the operating time of the processing equipment. In an embodiment of the present invention, systems 200 and 300 (Figure 1B) are designed to not use windows in the reaction zone; that is, a parallel propagation/gas flow system is used in which energy enters from upstream of the reaction. Therefore, more energy and power can be coupled into the plasma from the microwave energy source, allowing the processing temperature of the hydrocarbon input material to be higher. The lack of windows and the greater volume within waveguide 205, compared to the limited reaction chamber volume in conventional systems, greatly reduces particle accumulation problems that result in limited run time, thereby improving the generation efficiency of the microwave processing system.

The microwave energy 209 in FIG. 1A generates a microwave plasma 206 in a supply gas and/or a process material in a plasma zone having a length L1 (shown in FIG. 1A-FIG. 1B) of the length of the FEWG 205. The microwave energy 209 may also propagate into the reaction zone to interact directly with the process material stream 208b. The plasma zone having a length L1 is located within the FEWG LB portion having a smaller cross-sectional area, and the microwave energy density is higher than that in the length LA. In some embodiments, a supply gas different from the process material is used to generate the microwave plasma 206. The supply gas may be, for example, hydrogen, helium, a rare gas (such as argon), or a mixture of more than one type of gas. In other embodiments, the supply gas is the same as the process material, wherein the process material is a material that produces a separation component.

In some embodiments, the supply gas and/or process material inlet 202 is located upstream of the FEWG LB section, or within the FEWG L0 section, or within the FEWG LA section, or upstream of the FEWG LA section. In some embodiments, the FEWG L1 section extends from a location along the FEWG downstream of where the supply gas and/or process material 208a enters the FEWG to the end of the FEWG or to a location between the supply gas and/or process material inlet and the end of the FEWG 205. In some embodiments, the FEWG L1 section extends from where the supply gas and/or process material 208a enters the FEWG to the end of the FEWG or to a location between the supply gas and/or process material inlet and the end of the FEWG.

The generated plasma 206 provides energy for the reaction occurring in the treatment material 208b within the reaction zone 201 of the FEWG 205 having a reaction length L2. In some embodiments, the reaction zone L2 extends from the position where the treatment material 208a enters the FEWG 205 to the end of the FEWG 205 or to a position between the inlet of the treatment material and the end of the FEWG 205. Given appropriate conditions, the energy in the plasma 206 will be sufficient to form separated components from the treatment material molecules. Additional hydrocarbon cracking reactions and/or modification of the generated carbon material may occur in the high temperature plume 220, which may also be referred to as a plasma afterglow. In some embodiments, additional input materials may be introduced into the reactor at the inlet 202. For example, elements may be introduced during or shortly after the generation of the carbon material to functionalize the carbon material (such as, enhance bonding to the resin) or add (such as, bond, embed) the resin to the carbon material. One or more outlets 203 are configured to collect separation products from the FEWG 205 downstream of the reaction zone portion 201 of the FEWG where reactions occur in the process material 208b. In the example shown in FIG1A , the direction of propagation of the microwave energy 209 is parallel to the majority of the supply gas and/or process material flow 208b, and the microwave energy 209 enters the FEWG 205 upstream of the reaction zone 201 of the FEWG where the separation components are produced.

In some embodiments, a pressure barrier 210 transparent to microwave energy may be located within the microwave energy source 204, near the outlet of the microwave energy source, or at other locations between the microwave energy source 204 and the plasma 206 generated in the FEWG. Such a pressure barrier 210 may be used as a safety measure to prevent the plasma from potentially flowing back into the microwave energy source 204. The plasma is not formed at the pressure barrier itself; instead, the pressure barrier is only a mechanical barrier. Some examples of materials that the pressure barrier may be made of are quartz, ethylene tetrafluoroethylene (ETFE), other plastics, or ceramics. In some embodiments, there may be two pressure barriers 210 and 211, wherein one or both of the pressure barriers 210 and 211 are within the microwave energy source 204, near the outlet of the microwave energy source, or at other locations between the microwave energy source 204 and the plasma 206 generated in the FEWG. In some embodiments, the pressure barrier 211 is closer to the plasma 206 in the FEWG than the pressure barrier 210, and in the event of failure of the pressure barrier 211, there is a pressure exhaust orifice 212 between the pressure barriers 210 and 211.

In some embodiments, a plasma backstop (not shown) is included in the system to prevent plasma from propagating to the microwave energy source 204 or the supply gas and/or process material inlet 202. In some embodiments, the plasma backstop is a ceramic or metal filter with holes to allow microwave energy to pass through the plasma backstop, but prevent most plasma species from passing through. In some embodiments, most plasma species will not be able to pass through the plasma backstop because the holes will have a high aspect ratio and the plasma species will recombine when they hit the sidewalls of the holes. In some embodiments, the plasma backstop is located between sections L0 and L1 or in section L0 (in embodiments where the inlet 202 is in section L0) and the microwave energy source 204 upstream of section L1 and downstream of the inlet 202.

FIG. 1B shows another embodiment of a microwave chemical processing system 300 in which the supply gas and the processing material are injected at different locations. According to some embodiments, the microwave chemical processing system 300 generally includes: a FEWG 305; one or more supply gas inlets 302 configured to receive a supply gas 308a flowing into the FEWG 305; one or more processing material inlets 310 configured to receive processing materials 311a; and a microwave energy source 304 coupled to the FEWG 305; and other elements not shown for simplicity. The location of the processing material inlet 310 is downstream of the location of the supply gas inlet 302, wherein the downstream is defined in the direction of microwave energy propagation. In some embodiments, the microwave circuit 307 controls the pulse frequency when the microwave energy 309 from the microwave energy source 304 is pulsed. In some embodiments, the microwave energy from the microwave energy source 304 is a continuous wave.

The microwave energy 309 generates a microwave plasma 306 in the supply gas 308b within the plasma zone L1 of the length L of the FEWG 305. In some embodiments, the portion L1 extends from a location along the FEWG 305 downstream of the location where the supply gas 308a enters the FEWG 305 to the end of the FEWG 305 or to a location between the inlet of the supply gas and the end of the FEWG 305. In some embodiments, the portion L1 extends from the location where the supply gas 308a enters the FEWG 305 to the end of the FEWG 305 or to a location between the inlet of the supply gas and the end of the FEWG 305. One or more additional process material inlets 310 are configured to receive process materials flowing into the FEWG at a second set of locations downstream of the supply gas inlet 302. The generated plasma 306 provides energy for reactions occurring within the reaction zone 301 of the FEWG 305 having a reaction length L2. In some embodiments, portion L2 extends from the location where the process material 311a enters the FEWG 305 to the end of the FEWG 305 or to a location between the inlet of the process material and the end of the FEWG 305. Given appropriate conditions, the energy in the plasma will be sufficient to form separate components from the process material molecules. Additional hydrocarbon cracking reactions and/or modification of the produced carbon material may occur in the high temperature plume 320.

In some embodiments, additional input materials may be introduced into the reactor at the process material inlet 310. For example, elements may be introduced during or shortly after the production of the carbon material to functionalize the carbon material (e.g., to enhance bonding to the resin) or to add (e.g., bond, embed) the resin to the carbon material. One or more outlets 303 are configured to collect separation products from the FEWG 305 downstream of the portion 301 where the reaction occurs. In the exemplary system 300 shown in Figure 3, the propagation direction of the microwave energy 309 is parallel to the majority of the supply gas flow 308b and the process material flow 311b, and the microwave energy 309 enters the FEWG upstream of the reaction portion 301 of the FEWG where the separation components are produced.

In some embodiments, the FEWG (such as 205 in FIG. 1A and 305 in FIG. 1B) is configured to maintain a pressure of 0.1 atm to 10 atm, or 0.5 atm to 10 atm, or 0.9 atm to 10 atm, or greater than 0.1 atm, or greater than 0.5 atm, or greater than 0.9 atm. In many conventional systems, microwave chemical processing is operated under vacuum. However, in embodiments of the present invention where plasma is generated within the FEWG, operating in a positive pressure environment helps prevent the generated plasma from feeding back into the microwave energy source (such as 204 in FIG. 1A and 304 in FIG. 1B).

FEWG (such as 205 in FIG. 1A and 305 in FIG. 1B) may have a rectangular cross section of 0.75 inches by 3.4 inches in length LB to correspond to a microwave energy frequency of 2.45 GHz. For other microwave frequencies, other dimensions of LB are possible, and these cross-sectional dimensions may be 3-6 inches depending on the waveguide mode. FEWG (such as 205 in FIG. 1A and 305 in FIG. 1B) may have a rectangular cross section of, for example, 1.7 inches by 3.4 inches in length LA to correspond to a microwave energy frequency of 2.45 GHz. For other microwave frequencies, other dimensions of LA are possible. It is noteworthy that the FEWG is used as a chamber where plasma is generated and a reaction of the process material occurs, rather than having a separate waveguide and quartz reaction chamber as in conventional systems. Using the FEWG as a reactor chamber provides a much larger volume (such as up to 1000 L) where gas reactions may occur. This achieves a high flow rate of the process material to be processed without being limited by the accumulation of carbon particles as occurs in conventional systems. For example, the flow rate of the process material entering the waveguide (such as 205 in FIG. 1A and 305 in FIG. 1B) through the inlet (such as 202 in FIG. 1A and 310 in FIG. 1B) can be 1 slm (standard liters per minute) to 1000 slm, or 2 slm to 1000 slm, or 5 slm to 1000 slm, or greater than 1 slm, or greater than 2 slm, or greater than 5 slm. The flow rate of the supply gas entering the waveguide (such as 205 in FIG. 1A and 305 in FIG. 1B) through the inlet (such as 202 in FIG. 1A and 302 in FIG. 1B) can be, for example, 1 slm to 1000 slm, or 2 slm to 1000 slm, or 5 slm to 1000 slm, or greater than 1 slm, or greater than 2 slm, or greater than 5 slm. Depending on the gas plasma properties (such as the secondary electron emission coefficient) to obtain sufficient plasma density, the flow rate can be 1 slm to 1000 slm, and the pressure up to 14 atm.

In some embodiments, a plurality of FEWGs may be coupled to one or more energy sources (such as microwave energy sources). The FEWGs in these embodiments may share some or all of the features in the system described above. The supply gas and treatment material input in these embodiments may also share some or all of the features described above. In some embodiments, each FEWG has a reaction zone. In some embodiments, plasma is generated from the supply gas in the plasma zone in each FEWG, and the reaction length of each FEWG is used as a reaction zone for separating the treatment material into individual components. In some embodiments, the reaction zones are connected together, and the microwave chemical treatment system has an outlet for separating components. In some embodiments, the reaction zones are connected together, and the microwave chemical treatment system has an outlet for separating components more than one. In some embodiments, each reaction zone has its own outlet for separating components. In some embodiments, a multi-chamber reactor may allow carbon materials to be produced and modified without the need for additional treatment, and/or directly input into a resin/polymer. Other examples of multiple components (such as multiple reaction zones, multiple energy sources) are described in the aforementioned U.S. Patent No. 9,767,992.

3D Carbon Structure

Composite materials and methods of the present invention include high surface area 3D carbon materials that produce a porous matrix structure (such as, voids or open spaces in and around the sub-particles of carbon particles) for bonding to composite materials to obtain strength and conductivity. Using graphene as an exemplary type of carbon, conventional graphite or two-dimensional (2D) graphene nanosheets (GNP) materials are generally elongated with a flat surface, and are about 200nm long. In order to form a conventional composite material with GNP as shown in the schematic diagram of Figure 2, GNP 410 is encapsulated in a first resin to form particles 420, particles 420 are dried, and particles 420 are then added to a second resin to form a composite material 430. Therefore, in these conventional GNP-resin composite materials, GNP is simply encapsulated in a first resin, and the strength of composite material 430 is generally limited by the resin-resin bond between the first resin for forming particles 420 and the second resin in which particles 420 are dispersed. Conventional GNP composites (such as those without functionalized GNPs) are generally not reinforceable without affecting the elastic modulus, and often delamination occurs because the GNPs are not chemically connected to each other or to the bulk resin.

In contrast, the 3D carbon structure (such as 3D graphene structure) of the method and material of the present invention has a matrix connected by intrinsic 3D, thereby forming a longer material used as a 3D solid structure, increasing three-dimensional strength. The 3D carbon structure enables polymers to penetrate into the porous matrix of the structure, and provides mechanical interlocking between carbon and polymers by the geometry and high surface area of the structure. 3D carbon can also be functionalized, as will be described in more detail later, by carbon-resin bonds to promote chemical connection. In addition, the composite material formed by the 3D carbon material can provide independent control of strength and modulus by customizing the geometry of the 3D structure of carbon.

Fig. 3A shows a schematic diagram of a carbon particle 500 as a 3D graphene particle according to some embodiments. Different from other 3D forms of carbon materials, the unique structure of the 3D carbon material (such as, graphene nanosheet) produced by the plasma of the present invention is structured as a porous matrix. The 3D graphene particles may include graphene nanosheet sub-particles, wherein the sub-particles are in the form of single-layer graphene (SLG) sub-particles, few-layer graphene (FLG) sub-particles and/or multi-layer graphene (MLG) sub-particles. Carbon particles 500 are shown as having SLG sub-particles 510a, 510b, 510c and FLG sub-particles 520a, 520b. The 3D graphene of the present disclosure may contain only one form of graphene, such as only SLG, FLG or MLG, or may be a combination of one or more forms, such as SLG and FLG or SLG and MLG. In some embodiments, the 3D graphene may be primarily FLG, such as having greater than 50%, greater than 70%, or greater than 90% FLG sub-particles in the carbon particle 500. In some embodiments, the 3D graphene may be primarily MLG or SLG, such as having greater than 50%, greater than 70%, or greater than 90% MLG or SLG sub-particles in the carbon particle 500. Although the particle 500 is shown as having only GNPs, the carbon particles of the present disclosure may include other allotropes of carbon, such as, but not limited to, CNO, CNT, and nanowires.

The graphene nanosheet sub-particles form a porous matrix by three-dimensional growth and connection. That is, the 3D graphene particles 500 grow in the X-Y plane and in the Z direction, wherein the SLG sub-particles 510a, 510b and 510c and the FLG sub-particles 520a and 520b grow at various angles (such as orthogonally and at acute angles) relative to each other during the formation of the sub-particles. For example, the FLG sub-particle 520a may be first formed during hydrocarbon cracking, and then the SLG sub-particles 510a, 510b and 510c may grow from the edge and/or base face position of the FLG sub-particle 520a. The FLG sub-particle 520a has a graphene layer that grows mainly in the X-Y plane, while the SLG sub-particles 510a, 510b and 510c grow when their base faces are outside the X-Y plane and oriented in the Z direction.

Therefore, the overall growth of graphene particles 500 is in the X-Y plane and in the Z direction. Various sub-particles of particles 500 are interconnected at various edge and base (flat surface) positions, wherein connections 540a, 540b and 540c may be carbon-carbon bonds, which are attributed to the connection being formed during the formation of graphene sub-particles. Connection 540a is at an edge-edge position between the edge of FLG sub-particle 520a and the edge of SLG sub-particle 510c, while connection 540b is at an edge-base face position between the edge of FLG sub-particle 520b and the base face of SLG sub-particle 510c. Connection 540c is at a base face-base face position between the graphene nanosheet layers of FLG sub-particle 520b. These connections between sub-particles provide a pore matrix in a 3D manner, which is conducive to being incorporated into a composite material. The connection between the sub-particles can be, for example, through covalent or non-covalent bonds between the carbon lattices of two or more sub-particles, such as through the growth of one sub-particle from a site in another sub-particle. The 3D graphene structure can also include curling, wrinkling or folding of the nanosheet, where these features are retained as a three-dimensional geometry due to the interconnection with the surrounding sub-particles.

FIG3B shows 3D graphene particles 501, 502, and 503 incorporated into a polymer 550 according to some embodiments. The 3D graphene particles 501, 502, and 503 may be as-formed in a reactor, or may be particles that have been reduced in size from larger particles formed in a reactor. The particles 501, 502, and 503 are shown dispersed in the polymer 550, which may be facilitated by tailoring the particles in the reactor to bond the particles 501, 502, and 503 to the polymer 550 (such as by functionalizing and/or mixing the polymer with the particles, as described in other parts of this disclosure).

The 3D carbon structure of the material of the present invention provides a porous matrix, which is used as a scaffold structure into which the resin can penetrate and interlock. The pores can be between sub-particles, as indicated by pore 530, or between MLG or FLG layers, as indicated by pore 535. The pores of the 3D carbon material of the present invention can also be referred to as openings, holes or recesses, into which the resin can penetrate and entangle with the carbon particles, such as to increase the mechanical strength between the carbon additive and the polymer. The pores also provide a large amount of surface area for carbon to be bonded to the resin. In some embodiments, the pores may have a pore width of, for example, 1nm to greater than 50nm. The pores can be produced in a bimodal or unimodal mode, and the pore width is very narrow. In some embodiments, the carbon particles have a mesoporous structure with a wide pore size distribution (such as, multimodal distribution). For example, mesoporous particle carbon can contain a multimodal distribution of pores, and the size of the pores is 0.1nm to 10nm, 10nm to 100nm, 100nm to 1μ and/or greater than 1μ. For example, the pore structure may contain pores with a bimodal distribution of sizes, including smaller pores (such as, 1 nm to 4 nm in size) and larger pores (such as, 30 nm to 50 nm in size). Without being limited by theory, such a bimodal distribution of pore sizes in the mesoporous carbon particulate material may be beneficial in a composite resin system by achieving modulation of properties. For example, a larger amount of larger pores may be used to increase tensile strength, while a larger amount of smaller pores may be used to increase elastic modulus. In some cases, the void space distribution (such as, pore size distribution) within the structure may be bimodal or multimodal, and the various modes of pore size distribution may be tailored to customize the final composite product (such as, maximize, minimize, or achieve a desired range of properties, such as physical properties, mechanical properties, chemical properties, and/or electrical properties). As a non-limiting example, the void space may include a larger percentage of larger void spaces (such as, 50% or more), wherein the larger void spaces are more easily broken than the smaller void spaces, thereby allowing the material to be enhanced in different ways.

The 3D carbon material of the present invention provides benefits that are superior to conventional carbon materials. For example, conventional 3D graphene can be composed of crumpled graphene sheets. Graphene sheets are generally desirable because the hexagonal carbon lattice structure is inherently continuous along the face of the sheet. Conventionally, graphene sheets are connected to each other from the base face to the base face to form a stacked layer, wherein any gap between these long graphene sheet layers is likely to collapse. In contrast, compared with the graphene sheets that have been connected to carbon, as in the embodiment of the 3D carbon material of the present invention, it is counterintuitive to connect nanosheets together. However, the 3D structure of graphene nanosheets connected at different positions provides a structure with a fixed open porosity, in which the pores (such as, gaps or openings into which the resin can penetrate and bond with it) are unlikely to collapse (such as, compression or size reduction). Furthermore, connections between graphene layers and between sub-particles at various locations such as edge-edge, edge-base plane, and base plane-base plane can provide larger pores than between stacked layers of substantially parallel sheets in conventional graphene.

Because the carbon-carbon bonds connecting the sub-particles are formed during the growth of the carbon particles (rather than non-carbon bonds between the already formed sub-particles, which may also contain contaminants), in the 3D carbon materials of the present invention, properties such as electrical conductivity and thermal conductivity are improved. In addition, in some embodiments, the location and number of 3D interconnections between sub-particles can be customized to achieve certain features. For example, a combination of edge-edge, edge-base face and/or base face-base face connections can enable properties (such as electrical conductivity and/or thermal conductivity) to be multi-directional (such as, X, Y and Z directions; three-dimensional), rather than mainly in the X-Y plane as in conventional graphene sheets. This multi-directionality of properties can be used to reduce the need for carbon materials in oriented composites. Without being limited by theory, edge-base face connections between GNPs can reduce the energy levels required for electrons to jump between GNPs. In one example, edge-base face connections can enable electrons traveling on the base face of a first GNP to bypass naturally occurring defects (such as vacancies) in the first GNP by jumping to a second GNP that is connected at its edge to the base face of the first GNP via a carbon-carbon bond. Thus, the 3D connections between GNPs enable electrons to be unrestricted and travel outside the base face, resulting in higher conductivity than the 2D electron flow paths of conventional sheets.

4A-4B show scanning electron microscope (SEM) images of examples of 3D graphene according to some embodiments. FIG. 4A shows FLG sub-particles 521 and SLG sub-particles 511 interconnected in a 3D manner (X, Y and Z directions), wherein the SLG sub-particles 511 are also curled in this image, providing additional 3D geometry. FIG. 4B shows interconnected GNPs of various sizes, demonstrating that in some embodiments, a distribution of sub-particle sizes can be formed and utilized in a carbon particle material. FIG. 4B also demonstrates the ability to grow different types of carbon-carbon growths (such as, seeding) with each other, such as different allotropes of carbon.

Fig. 4C shows the example of multi-shell fullerene 560 and multi-shell fullerene 570 with ligand 575, and in some embodiments, these two can be combined into the carbon material of the present invention alone or in combination.Ligand 575 is the carbon chain grown and extended from multi-shell fullerene 570, wherein the ligand length is in the range of about 5-20nm.Ligand 575 is the engineered feature part that allows the carbon of different terminal sizes to mix in resin.In one embodiment, when combined with resin, ligand 575 may break (such as, in the engineered position, as will be described later in the present disclosure), and it can provide the resin with the enhancement different from the multi-shell fullerene ball with larger size.In another embodiment, ligand 575 can be retained, such as to be better anchored in polymer.Ligand 575 can provide the benefit of such as dispersion of energy and/or realization change aspect ratio to obtain the bonding improvement between carbon and polymer.

Figures 4D and 4E show exemplary SEM images of carbon and resin combinations according to some embodiments. Figure 4D shows a carbon-resin system that is partially wetted to enable visualization of the voids 580 (such as pores) in and around the carbon sub-particles and particles. Figure 4E shows a more highly wetted carbon-resin system compared to Figure 4D, demonstrating the high degree of integration between carbon and resin that can be achieved in the present disclosure.

The 3D carbon structure of the present disclosure is made by a plasma reactor as described herein, which is capable of achieving a higher growth temperature than a conventional reactor. Because there is no dielectric barrier between the high-frequency energy source (such as a microwave source) and the reaction zone in an embodiment of the present invention, the high-frequency energy (such as microwave energy) can apply direct heating to the material to be cracked. In contrast, in a conventional reactor, high-frequency energy is an indirect heating source because the energy is applied to an ionized carrier gas, which is then applied to the hydrocarbon material. The growth temperature in the hydrocarbon cracking process of an embodiment of the present invention may be, for example, at least 3000K, with a highly local (such as, at the atomic level) temperature of, for example, greater than 10,000K or greater than 20,000K. These extremely high temperatures result in rapid decomposition of hydrocarbon gases, wherein highly controlled vapor growth allows 3D formation of carbon materials. In addition, the high growth temperature of an embodiment of the present invention enables the production of high phase purity carbon materials, such as a specific phase (such as GNP) with a phase purity greater than 95%, or greater than 97%, or greater than 99%. Higher growth temperatures allow higher structure carbon (e.g., higher degree of crystallinity) to grow, while amorphous carbon preferentially grows at low temperatures and has a low growth rate at these high temperatures. Therefore, the plasma reactors and methods of the present invention are uniquely capable of producing high phase purity carbon materials with little to no amorphous carbon. In one example of how to uniquely control carbon growth in some embodiments, highly structured carbon materials can be grown in the highest temperature zone of the reactor, and then the highly structured carbon materials can be decorated with amorphous materials in lower temperature zones of the same or another reactor to help disperse and/or promote wettable surfaces and favorable surface chemistry of specific terminal polymers.

In addition to producing extremely pure fractions of highly structured carbon materials, materials can also be formed with 3D porous structures as described above. In the reactor of the present invention, by controlling the process parameters that affect the growth rate of the carbon material, it is possible to form 3D connections between sub-particles. A parameter that can be used to affect the formation of 3D carbon particles of the present disclosure is partial pressure, wherein the reduction of process gas partial pressure (such as, methane content to the supply gas content for generating plasma) can cause the process gas to be out of supersaturated conditions. That is, the partial pressure of the process gas can be controlled to produce metastable conditions so that hydrocarbon substances emerge from the plasma. Adjusting the partial pressure of the process gas to change this metastable condition can be used to affect the growth of carbon particles. For example, a slower growth rate can be used to produce particles and sub-particles of larger size. On the contrary, a faster growth rate can be used to produce particles and sub-particles of smaller size, such as generating GNPs that grow in connection with each other, rather than generating long graphene sheets. The size of the particles produced therefore affects the characteristics of the carbon material, such as the density of the overall 3D carbon particle structure. In another example, the power level can also be controlled such as by changing the temperature in the reactor to affect the growth rate. Through aspects such as extremely high temperatures and control of various process parameters, the plasma reactor system of the present invention enables the production of unique carbon particles having sub-particles connected in a 3D manner to form a porous structure.

fiber

In some embodiments, in addition to the carbon additive (such as, graphene, MWSF, 3D carbon material, 3D graphene) combined with the resin, the composite material of the present invention also includes fiber as a reinforcing material. Fiber provides multiple benefits, such as being used as an additional 3D structure on which a 3D carbon material can be formed, providing a 3D geometric matrix for the composite material and providing a material with a high aspect ratio, thereby enabling the beneficial properties of the composite material (such as, high strength and/or anisotropic properties). Some embodiments of the composite material relate to carbon fibers (which may be referred to as carbon composite fillers (CCF)) combined with resin and carbon particles. Some embodiments of the composite material relate to non-carbon fibers (such as, non-carbon composite fillers (non-CCF), such as glass fibers) combined with resin and carbon particles. Some embodiments of the composite material can utilize chopped fibers added to resin and carbon particles. The types of fibers that can be used in some embodiments include, but are not limited to, carbon fibers, glass (Si), aramid, polyethylene, boron, ceramics, Kevlar or other spinning or weaving materials.

FIG. 5A shows a diagram of unique material processing involving fibers according to some embodiments. Fiber 610 may be, for example, carbon, ceramic, or metal fibers. In conventional composites, when combined with a resin binder, these fibers will break away from the binder in the formed composite. In some embodiments of the present disclosure, fiber 610 may be introduced into a reactor, which may or may not be the same reactor that produces the carbon particles, and the fibers are modified in the reactor (such as chemical or non-chemical etching, or surface treatment to roughen or change the surface chemistry of the fibers), as indicated by fiber 620.

Detailed view 625 shows an embodiment in which etching results in surface roughening of the fiber. Modification of the fiber can produce higher interfacial bonding between the fiber and the polymer compared to unmodified (e.g., unetched) fibers. For example, etching can be performed by adding oxygen-containing groups to the plasma region of the reactor, wherein in some embodiments, a partial pressure of O2, such as 0% to 21% or up to 100%, can be used. In a specific example, the glass fiber can be etched using oxygen-containing groups, wherein Si-O-C bonds will be formed between the resin and the glass fiber treated with O2 and the resin, or between the carbon particles in the resin and the treated glass fiber.

The modified fiber 630 is then used to form a composite material, as shown in FIG5B , where the modified fiber 630 is added to a carbon-resin matrix 640 to form a composite material 650. The carbon-resin matrix 640 is a resin containing carbon filler particles, such as the 3D carbon material disclosed herein. The resulting composite material 650 is an interconnected matrix of chemically bonded materials (fibers, carbon fillers, and resins) that provides improved properties, such as higher strength than conventional resin-fiber composites. In some embodiments, the fibers are integrated with a carbon material to produce a synthetic carbon matrix material to be added to a carbon-resin composite.

FIG. 6 shows a combination of a carbon material (such as the 3D carbon structure described above) of the present invention according to some embodiments with a fiber 710. For example, the composite material and method of the present invention may include a high surface area 3D carbon material 720, which is integrated with the fiber 710 during the composite material processing, such as in situ integration in a microwave reactor, to provide improved properties for the composite material, such as strength and conductivity. The resulting 3D carbon material on the 3D fiber structure provides a high surface area and pores (such as between fibers, within the 3D carbon and between the fiber and the 3D carbon) for mechanical interlocking and chemical bonding between the resin and the fiber-carbon structure. Depending on the end-use application of the composite material, the fiber 710 may be various sizes in different embodiments. For example, the fiber may be a nano-scale or macro-scale material, or the size may be about a fraction of an inch or several inches, such as a fiber ranging from 0.25 inches to 2 inches. The diameter of the fiber may be about 0.001 inches to 0.3 inches, but is not limited to nanometer to micrometer-sized diameters, depending on the final manufacturing technology (such as injection molding, resin transfer molding, manual layup, etc.). In one example, the 3D carbon material 720 can be 3D graphene grown onto the fibers 710, creating an even higher reinforcement matrix for the composite material than 3D graphene particles alone.

In some embodiments, the fiber 710 is modified (e.g., etched) in the same reactor that produces the 3D carbon material 720. In some embodiments, a microwave plasma reactor is used in conjunction with an etching gas to etch the fiber 710 within the plasma and thermal high temperature plume of the reactor, thereby promoting carbon growth directly to nucleation sites on the fiber 710. The ions within the plasma can etch the fiber and drive a gas phase cracking process that causes layers and three-dimensional structures of the carbon material 720 to grow onto the surface of the etched fiber. The use of a base fiber material (such as a metal, a dielectric rod, and a tube) coated (in whole or in part) with a carbon matrix structure can advantageously produce a reinforcement material with adjustable properties, enabling the formation of a composite material with adjustable material properties. The synthetic 3D carbon material deposited onto the 3D fiber is combined with a resin 730 to form a final composite material 740.

Figures 7A-7D show exemplary SEM images of 3D carbon material grown onto fibers using plasma energy from a microwave plasma reactor and thermal energy from a thermal reactor. Figure 7A shows an SEM image of intersecting fibers 711 and 712 on which 3D carbon material 720 grows on the fiber surface. Figure 7B is a high-magnification image of 3D carbon growth 720 shown on fiber 712 (the scale bar is 300 μm, compared to the scale bar of Figure 7A of 500 μm). Figure 7C is a further enlarged view (the scale bar is 40 μm), which shows 3D carbon growth 720 on fiber surface 715, in which the 3D nature of carbon growth 720 can be clearly seen. Figure 7D shows a close-up view of individual carbon (the scale bar is 500 nm), which shows the interconnection between the base face 722 and the edge face 724 of multiple sub-particles of the 3D carbon material 720 grown on the fiber. 7A-7D illustrate the ability to grow 3D carbon on 3D fiber structures, such as growing 3D carbon on carbon fibers, according to some embodiments.

In some embodiments, 3D carbon growth on fibers can be achieved by introducing multiple fibers into a microwave plasma reactor (such as, through the inlet 202 of the system 200 in Figure 1A) and using the plasma in the microwave reactor to etch the fibers. Etching produces nucleation sites so that when carbon particles and sub-particles are produced by hydrocarbon cracking in the reactor, the growth of the 3D carbon structure starts at these nucleation sites. The direct growth of the 3D carbon structure on the fiber is itself three-dimensional, providing a highly integrated 3D structure with pores into which the resin can penetrate. Compared with composite materials with smooth surfaces and conventional fibers that are usually delaminated from the resin matrix, this 3D reinforced matrix of the resin composite (including a 3D carbon structure integrated with high aspect ratio reinforcing fibers) obtains enhanced material properties, such as tensile strength and shear.

Functionalized Carbon

In some embodiments, the carbon material (such as the 3D carbon material described herein) can be functionalized to promote adhesion and/or add elements such as oxygen, nitrogen, carbon, silicon or hardeners. In some embodiments, the carbon material can be functionalized in situ (i.e., in the same reactor where the carbon material is produced) or in post-processing. For example, the surface of fullerenes or graphene can be functionalized with oxygen- or nitrogen-containing species that form bonds with the polymer of the resin matrix, thereby improving adhesion and providing strong bonding to enhance the strength of the composite material.

Embodiments include functionalized surface treatment of carbon (e.g., CNT, CNO, graphene, 3D carbon materials such as 3D graphene) using a plasma reactor (e.g., a microwave plasma reactor) as described herein. Various embodiments may include: in-situ surface treatment during the production of carbon materials that will be combined with binders or polymers in composite materials; and/or surface treatment after the carbon materials are produced (but still within the reactor).

Figure 8A shows a diagram representing functionalized carbon, where the 3D graphene of Figure 4A is shown along with FLG sub-particles 521 as modified with functionalized groups as represented by black and white dots 810. Figure 8B is a SEM of a 3D carbon material functionalized with a single percentage of a Group 6 non-metallic element. Although the functional elements cannot be visualized in this SEM, the interconnections of the GNP sub-particles 820 are clearly visible in Figure 8B.

Functionalized carbon can be used to enhance bonding with resin. In some embodiments, functionalized carbon can be grown on fiber matrix, such as described with respect to Figure 6. In some embodiments, carbon particles (alone or integrated on fiber) are functionalized in situ in the reactor producing carbon particles to be compatible with polymer. That is, in some embodiments, by promoting chemical bonding (such as covalent bonding) and/or physical bonding (such as, π-π interaction) and hydrogen bonding between carbon particles and resin, carbon particles are functionalized to be compatible with resin. For example, functionalization can include surface oxidation or nitridation with hydroxylation or nitrided carbon, so as to promote bonding with resin. In addition, surface preparation can be carried out to clean and prepare the carbon surface receiving polymer. Functionalization can also include surface doping or surface alloying, such as CxNy, AlxCy, SixCy, NiXCy, CuxCy, NxCy or elements such as Be, Sc, Mg, Ti and Pt. In some embodiments, the carbon may be functionalized with one or more of H, O, S, N, Si, aromatic hydrocarbons, Sr, F, I, Na, K, Mg, Ca, Cl, Br, Mn, Cr, Zn, B, Ga, Rb, Cs, amino groups, acid groups (such as, COOH, OH), or additional polymers.

In various embodiments of carbon materials and composite materials of the present invention, functionalized carbon surfaces can enhance surface wettability (such as, surface activity), and realize wetting enhancement between carbon materials and resins. For example, carbon can be functionalized to increase wettability (such as, forming a low contact angle with the resin), thereby improving the integration of carbon and resin. In some embodiments, chemical additives can be added to carbon-resin systems to allow particles to be better anchored in the resin, which can also increase the mechanical properties of the composite material formed. This is because the correctly anchored material will not settle from the resin system, but keeps completely suspended. The example of chemical additives includes but is not limited to nonionic surfactants and dispersants containing polyethylene oxide chains and hydrophobic groups, which allow carbon to be better chemically bonded to the polymer matrix.

In various embodiments of the composite material of the present invention, the mixture of resin and carbon remains in an unhardened state, which can then be used as a raw material for various applications (such as formed parts) or applied as a coating. Unhardened composite materials can be the type of resin systems (such as two-part systems or systems in which a crosslinking agent or hardener is added to initiate curing). In other embodiments, the carbon/resin mixture can directly produce a hardened material, such as in an embodiment in which carbon starting particles are functionalized with a hardener, and the functionalized carbon initiates crosslinking when entering the resin. Functionalized carbon particles with a hardener can be directly embedded in the resin in a reactor for producing and functionalizing carbon, as will be described in more detail in the next section. The resulting resin/carbon composite material (wherein carbon includes a hardener) can, for example, provide a composite material in a ready-to-mold state. The carbon in this molding scheme can be a carbon matrix material, in which functionalized graphene is designed to be a strength-reinforced material and a hardener.

FIG9 shows a schematic diagram of a field enhanced waveguide 905 as part of a microwave plasma reactor, wherein for simplicity, other parts of the reactor are not shown. FEWG 905 includes: a supply gas inlet 902, which is configured to receive a supply gas 908a flowing into FEWG 905; and a treatment material inlet 910a, 910b and 910c, which is configured to receive treatment materials 912a, 912b and optionally 912c. High frequency energy 909 generates plasma 906 in the supply gas 908a and/or treatment material 912a. The generated plasma 906 provides energy for the reaction occurring in the treatment material 908b in the reaction zone 901 of FEWG 905. In some embodiments, the treatment material 912a is a hydrocarbon substance, such as a gas, a liquid or a colloidal suspension, from which the carbon material will be produced by a cracking process. The treatment material 912b may be a substance such as a gas or a liquid to produce a functional group for in-situ functionalization of carbon in FEWG905. The treatment material 912c may be a functionalized or doped material (which is a different substance than the treatment material 912b), or may be a fiber as described above (such as a fiber matrix on which carbon particles will grow). In FIG. 9 , the treatment material inlets 910a, 910b, and 910c are shown at different locations upstream and downstream of each other, but in other embodiments, they may all be at the same location or a combination of the same and different locations. The location of the treatment material inlets 910a, 910b, and 910c may be used to change the location where the reaction occurs, such as within the plasma 906 and/or in the afterglow region 920, to customize the properties of the carbon material.

Functionalizing carbon using the reactor and method of the present invention provides unique advantages over conventional reactors and methods by introducing additional gas or liquid (containing functional elements, doping materials and/or hardeners) into the vicinity of the plasma that produces the carbon material. This allows hydrocarbon substances to be cracked during the growth of the carbon material or later near the functionalized material. Functional groups can be introduced directly into the plasma or plasma afterglow, on the newly manufactured surface of the produced carbon, and produce stronger bonds than carbon particles previously produced by functionalization. This is because the carbon surface has a high surface energy when the carbon is produced. Functionalization is carried out by gas-gas interaction; that is, in vapor form instead of, for example, wet chemistry. Conventional methods such as plasma enhanced chemical vapor deposition (PECVD) involve vapor form; however, functionalization in a hydrocarbon cracking plasma reactor is more difficult than standard PECVD because it is difficult to add other substances to the carbon cracking process. The introduction of other substances produces a large number of process parameters, all of which interact with each other. In an embodiment of the present invention, it has been found that functionalization during the carbon formation process is only possible in a small window of process parameters, such as to prevent the growth of functional groups on the reactor surface, which will terminate the hydrocracking process.

Functionalization of in situ carbon materials (in the reactor while the carbon material is growing) is achieved by controlling factors such as partial pressures, flow rates of supply and process gases, power levels of high frequency energy, and use of non-equilibrium plasma modes, as well as utilizing reactors of different designs (such as using different reactor zones or different temperature and energy zones). In addition, functionalization can be performed in the plasma itself or in a subsequent portion of the particle flow (such as a high temperature plume following the plasma) to further tailor the chemical reaction between the functionalizing element and the carbon material.

In some embodiments, the reactor may include different zones, wherein the generation of carbon particles and functionalization of carbon particles may occur in one or more zones. For example, the generation and functionalization of carbon particles may occur substantially simultaneously in one zone. In another example, carbon particles may be generated in one zone of the reactor, and then functionalization may occur in a subsequent zone. In another example, (i) carbon particles may be generated in a first zone of the reactor where a microwave plasma is present; (ii) a plurality of fibers may be introduced into the plasma in the first zone and/or into a second zone containing a hot high temperature plume of the reactor, wherein the fibers are etched and 3D carbon grows onto the fibers, and/or the fibers adhere together at interconnection points; and (iii) functionalization of carbon may occur in a third zone.

In some embodiments, 3D carbon materials, whether functionalized or not, can advantageously provide anisotropy (e.g., directionality in one or more of the X, Y, Z dimensions) through the natural randomness of their structure. In some embodiments, 3D carbon materials, whether functionalized or not, can provide multi-directional enhancement of properties, such as increased conductivity through 3D interconnection of carbon sub-particles.

Because the carbon-resin bond is promoted by carbon functionalization, the reinforcing carbon filler of the composite material of the present invention is more dispersed (such as, a low aggregation or less aggregation dispersion) compared to conventional composite materials, and a high loading of carbon filler material (such as, greater than 40% or greater than 50%) can be achieved in the resin system. In some embodiments, the carbon filler particle size in the composite material is relatively small, such as 200-400nm, which helps to disperse. The carbon-loaded resin has processability (rheology of the polymer-carbon mixture before curing), which is suitable for various applications, including but not limited to prepreg applications, molding applications and extrusion processes. The carbon filler particles in the carbon-resin mixture of the present invention are suspended, similar to a colloidal solution, which is attributed to the filler material being well dispersed and fully wetted, wherein in some cases, the filler can also be chemically bonded to the resin.

In some embodiments, the carbon-metal matrix material is produced by doping carbon or mixing carbon with a metal, such as by impregnating a metal on carbon by chemical bonding using a plasma reactor. In some embodiments, the size of the carbon-metal matrix material particles can be reduced by mixing with a resin, creating a carbon/metal interface so that the carbon/metal particles of reduced size within the resin composite can be bonded to a metal support structure. Metal doping of carbon can be used to produce organometallics, where the carbon particles are functionalized with a metal to be compatible with a metal-based binder such as a carbon-infused metal or a carbon-metal covetic material. The terms "organometallic" and "organometallic" are used interchangeably.

Compared with conventional materials, the bonding between carbon additives, resin and fiber (if included) provides improved composite material properties. For example, the functionalized carbon structure grown on the fiber material provides energy transfer modification so that the energy applied to the composite material is distributed in all sub-components of the fiber reinforced composite material system. In another example, crack propagation is alleviated by stress termination (for example, the termination of dangling bonds), and stress termination is realized by functionalization and/or generation of carbon-carbon connections between the sub-particles of the carbon material of the present invention. Toughening resins can also be prepared, wherein plastics can be such as by adjusting the concentration of functional substances and/or regulating the bond type between carbon and polymer to elastic behavior to control. In some embodiments, compared with conventional composite materials that generally cause higher viscosity compared to higher enhancement, because functional groups are integrated into carbon along with the growth of carbon, high strength can be achieved without increasing viscosity.

In addition to the functionalization of the carbon material described in this section, other treatments of the carbon material can also be used to enhance the combination of carbon and resin. Exemplary methods include etching carbon surface, surface roughening and/or treating carbon surface to remove pollutants. In some embodiments, the clean surface of carbon that is not exposed to the environment can itself be used as a functionalized surface, such as by injecting carbon directly into the resin composite material system, so that the carbon material is not exposed to environmental conditions (such as, the surface is only exposed to resin after carbon is formed). Other examples of the modification or treatment of carbon material include, for example, structural or morphological modification, surface promotion (such as, by surface chemistry) and the use of environmental constraints (such as, via creating specific environmental conditions that produce carbon material, such as different types of inert atmospheres in reactors, promote the bonding of carbon material to resin).

In situ resin embedding

In some embodiments, carbon particles are produced in a reactor and combined with resin (such as, mixing) in a container. In other embodiments, carbon and resin are combined by directly embedding carbon particles (functionalized or non-functionalized) in the resin in the reactor for growing (and optionally functionalized) carbon particles, so that contact from external resources is not required. That is, resin and carbon can be combined in the reactor without any human contact. For example, resin flow injection or liquid injection can be used in the reactor to produce steam-steam interactions between carbon particles and polymers. In some embodiments, composite material includes producing graphene nanoparticles (such as, 3D graphene) or carbon nano onions, which can be injected into adhesives (such as, resins or polymers) to produce composite materials. Some embodiments include injection molding or forging parts from composite materials.

Returning to FIG. 9 , in some embodiments, the treatment material 912c may be a resin introduced into the inlet 910c. Types of resins that may embed the carbon material include thermosets, thermoplastics, polyesters, vinyl esters, polysulfones, epoxies (such as novolacs or other epoxies), rigid amines, and polyimides. The treatment material 912b may be a gas or liquid used to functionalize the carbon material to be more compatible with the resin (such as to enhance or promote bonding or wetting with the resin).

Directly embedding carbon particles in situ into resin can provide multiple benefits, such as avoiding exposure of carbon particles to the surrounding environment (such as, air and moisture) and generating stronger bonds between carbon and resin. This is because the surface of carbon particles is more reactive immediately after particle formation compared with exposure to the surrounding environment (such as, oxygen) after collection from the reactor. Therefore, in the reactor producing carbon particles, before the carbon particles are present in the reactor, the carbon particles are combined with polymer particles, which can provide enhanced bonding between carbon and resin and improved composite material properties. In hydrocarbon cracking plasma reactors, the in-situ integration of resin and carbon material is contrary to conventional practice, because the introduction of additional substances into the cracking process greatly increases the complexity of determining the process parameters that can be successfully used, as described above for in-situ functionalization. For example, it is extremely complicated to introduce resin into the reactor without causing the resin to accumulate on the reactor wall or not affecting the desired growth characteristics of carbon, and it is not simple from the perspective of conventional practice.

Extra Energy/Blend

Figure 10A-Figure 10B shows a simplified schematic diagram of an embodiment in which the size of carbon particles can be reduced when carbon particles are combined with resin to produce a composite material. That is, during the process of combining with the resin, the size of the carbon particles is reduced from the initial particle size to the final particle size. In Figure 10A, carbon particles are produced in a reactor 1010, which may be, for example, a microwave plasma reactor as described herein. The carbon particles 1020 produced may be modified (such as, functionalized) or not modified in the reactor 1010, and may have a nanometer to micron size, such as about 100 μ, which is used as a starting particle and as a filling material combined with a resin 1030. In some embodiments, the starting particles may be injected into an uncured or unhardened resin bath (such as, a certain volume of resin contained in a container). In other embodiments, mixing may be achieved by injecting the resin flow into the carbon flow of the reactor (such as in a plasma zone and/or in a plasma afterglow). Energy 1040 is input into the carbon/resin mixture, wherein energy 1040 may be mechanical mixing 1045, which applies mechanical forces, such as shear forces, to the particles in the resin. In addition to mechanical mixing 1045 or in place of mechanical mixing, the energy addition system may also include thermal energy or high-frequency energy input to help the process. For example, large particles may be injected into the resin, and mechanical energy may be added together with thermal energy and/or microwave energy. Additional energy 1040 (such as mechanical energy, thermal energy and/or high-frequency energy) may be used for various purposes, including but not limited to helping decompose carbon starting particles and helping the process of carbon chemically bonding to polymer (resin). Supplemental energy 1040 may be supplied, for example, in the form of mechanical mixing 1045, thermal heating and/or microwave heating.

FIG. 10B shows a diagrammatic illustration showing the effect of supplemental energy 1040 on particle size, wherein the energy may be, for example, mechanical energy (such as, mechanical mixing 1045) or thermal energy. The particles of the starting material may be aggregates 1050 of up to, for example, 100 μ in size. Energy 1040 may be imparted to the particles via one or more of applying shear forces to the particles, homogenizing the particles, or mixing the particles. Mechanical or thermal energy may break the particles into smaller sizes 1052, 1054, and 1056, which may result in new surfaces for resin (such as, polymer) bonding. Smaller sizes 1052, 1054, and 1056 may involve breaking carbon particles into sub-particle groups of various sizes, such as GNP sub-particle groups. As previously discussed, the newly exposed surfaces that have not yet been exposed to the surrounding environment may provide increased bonding to polymer molecules.

In some embodiments, mechanical shearing is used to break up carbon (or formulated/functionalized carbon) particles, thereby facilitating the dispersion of carbon throughout the resin. Dispersion can be achieved by mechanical mixing, chemical methods (such as, adding organic solvents or surfactants to promote bonded carbon-organic polymers) or a combination of these methods. For uniformity improvements in material properties throughout the composite material and improvements in the properties themselves, increasing dispersion may be desirable. Examples of improved properties include, but are not limited to, mechanical strength, toughness, flexural modulus, conductivity, and density (such as, lighter). Compared to the fewer larger surfaces of the starting carbon particles, the increased number of small shear surfaces of the mixed carbon particles (which can be maintained as 3D carbon structures in some embodiments) allows for greater amounts of resin/surface anchoring. This higher surface binding amount can result in, for example, improved conductivity and/or mechanical properties. Typically, the smaller particles produced by the energy input into the resin/carbon mixture change the surface area, structure, and surface activity compared to the larger size of the starting carbon particles. Surface area refers to the total area of the carbon material surface, including the area that can interact with the resin.

Particle size and shape can affect surface area. Structure describes the shape of the particle. Structure can be affected by the number of particles (or sub-particles) that are fused together and the configuration of particles within the aggregated particle. Surface activity is related to the strength of the surface interaction between the carbon filler material and the resin/polymer. Surface activity can affect the dispersion characteristics of the carbon material within the resin.

In other embodiments, external energy can be applied to heat or cool the resin to change the viscosity. For example, the resin viscosity can be changed during mixing to change the shear force on the carbon particles. In another example, the viscosity of the resin can be changed to change the elastic modulus of the final composite material (such as, the increase in the viscosity of the composite material can help suspend the carbon particles in the mixture). In some embodiments, cooling or heating can be used to help harden or cure the polymer.

Engineering defects

In some embodiments, the carbon material of the present disclosure has engineered defects in the carbon particles to achieve further adjustability (such as, customization) of carbon, and thus achieve the adjustability of the properties of the composite material made of defect engineered carbon particles. Embodiments include engineering defects into structured carbon materials, that is, carbon materials designed to have defects specifically for bonding with resins, such as 3D carbon structures and/or functionalized carbon materials. In some embodiments, carbon particles are produced in a microwave reactor, and defects are engineered in the microwave reactor to intentional defect positions between sub-particles or particles (which can also be referred to as agglomerates) in carbon particles, so that particles or aggregates are decomposed (such as, fragmented) from the starting particle size into a smaller final particle size, which is determined by the defect position. In some embodiments, the energy dissipation in the system is controlled to mitigate or concentrate force, such as by engineering a 3D structure with a porous matrix geometry and/or weakened bonds so that energy can move to or along a specified surface. This achieves different interactions between filler-filler and filler-polymer, wherein the filler is a carbon-based material.

FIG. 11A shows a schematic diagram of an engineered defect according to some embodiments, using 3D graphene as an exemplary carbon material. The 3D graphene particle 1100 is made of a plurality of few-layer graphene sub-particles 1110 (which may also be MLG and/or SLG sub-particles in various embodiments), each sub-particle 1110 being made of up to a graphene layer 1112, as shown in a detailed cross-sectional view 1120. The FLG sub-particles 1110 are building blocks of the 3D graphene particles 1100, and are interconnected at various edges 1115 in this embodiment, but the connections may also include edge-base face and base face-base face positions. The interconnected sub-particles 1110 form a 3D assembled structure having open spaces (such as, pores) between the sub-particles 1110, as previously described with respect to FIG. The sub-particles 1110 and the interconnections are formed in a plasma reactor, as described herein. The intrinsic mechanical properties (eg, elastic modulus, tensile strength) of a single layer of graphene (eg, layer 1112) are not impaired or are maintained during the creation of particle 1100, ie, with minimal base face defects.

An example of an engineered defect is to create a selectively weakened site within the particle 1100. In a post-plasma process, such as in the high temperature plasma afterglow of a reactor, the interconnected contact points between the FLG sub-particles 1110 can be selectively weakened by the focused and concentrated impact of the sputtered atoms 1140. The connection points are high-angle contact points with sharp bumps or transitions that concentrate the sputtering energy while minimizing the impact of ions on the flat, low-angle base surface 1118 of pure graphene. The sputtered atoms 1140 are depicted as argon in this embodiment, but can be other elements, such as but not limited to nitrogen, oxygen, ammonia (NH4) or other active and reactive species. In some embodiments, a selective bias field can be applied to the 3D aggregate structure 1100 so that the bias field is concentrated at the edges of the FLG sub-particles 1110, and the sputtered atoms are further focused at these selective sites accordingly. The location of the defect can be selectively selected based on, for example, the injection mode of the sputtered atoms, the gas particle pressure, and the plasma temperature. The weakening of the sites results from a reduction in the number of carbon-carbon bonds at the attachment points. A greater number of weakened sites will cause the particle 1100 to fragment into smaller particle sizes, for example when shear or mixing forces are applied.

In some embodiments, the carbon can be grown weakly bonded from the beginning, or the carbon can be grown and then defects added. In some embodiments, defects can be engineered into carbon particles using a plasma reactor with a multi-stage reactor zone. High-frequency energy (such as microwave energy) can effectively target the location where the energy is applied, thereby enabling selectivity in defect generation in the embodiments of the present disclosure. In contrast, thermal energy acts on bulk properties, which may damage the inherent structure of carbon materials (such as graphene). The use of high-frequency energy (such as microwave energy) advantageously maintains the characteristics or properties of the sheet and can be primarily targeted at the interconnections between the sub-particles, whether the connection is edge-edge type, edge-base type or base-base type.

Figure 11B shows the benefits of engineered defects in the size of custom carbon particles for composite materials. In Figure 11B, particle 1100 has multiple defects, which are engineered to the sub-particle edge, such as at defects 1150a, 1150b and 1150c. High-energy shearing process or any shearing process that combines energy (such as, from the energy applied during the mixing of carbon and resin) into the fluid causes particle 1100 to be broken into smaller fragmented particles 1101 and 1102 at the defect position. The average final particle size (its size or volume can be measured) of fragmented particles 1101 and 1102 is less than the average initial particle size of particle 1100. Smaller particles 1101 and 1102 are easily dispersed into fragments due to the newly cut close (wettable) surface produced at the shearing position of defects 1150a, 1150b and 1150c. Therefore, by applying high-energy shearing force during mixing particles in uncured/unhardened resin, the newly cut surface is immediately in contact with the resin and is not contaminated. At the same time, the fracturing of the 3D particles during the high energy shear process within the resin maintains the inherent mechanical integrity of the FLG sub-particles 1110 .

The ability of engineered structured carbon materials to break down into specific sizes is a unique and important capability of structured carbon that facilitates improved composites containing those materials. The materials are engineered to achieve minimal exposure to ambient conditions even when left in the ambient environment for a period of time. Larger engineered materials keep the internal materials sealed to achieve exposure only at specific moments in processing (such as when additional energy is found in shear or mixing when combining carbon with resin). Engineered materials have specially adjusted fracture surfaces, which in turn achieve specific behavior in post-processing to provide carbon-resin composites with end-use properties.

In some treatment schemes, the structured carbon has at least one adjusted fracture surface. Such structured carbon with an adjusted fracture surface is mixed with additional materials, and its amount and formulation are controlled at least in part based on the application-specific final component specifications. In addition, the specific fracture surface of the structured carbon can be controlled during the treatment in the reactor. Strictly speaking, as an example, by using in-reactor processing techniques, the structured carbon produced can be adjusted to have a fracture surface engineered for specific final product characteristics. For example, in a formulation, the structured carbon produced in a microwave reactor is deliberately not compressed before being used in a post-processing step, so the only necessary post-processing required is the step of mixing with the resin, which produces a compounded composite material.

In some engineered formulations, the fracture planes in the carbon materials of the present invention are defined by the presence or absence of bonding/non-bonding carbon atoms. The fracture planes can be engineered by introducing weakly bonded regions into the lattice, by introducing gaps or holes, or by introducing dangling bonds. These weakly bonded regions can be intentionally created by introducing non-carbon chemicals into the carbon system to form different bonds. For example, by introducing a measured amount of oxygen into the reactor during the formation of structured carbon, a weaker C-O bond (such as, weaker than a C-C bond) can be formed in the lattice. Due to the different energies associated with each type of bond, the flat structure of the lattice can be engineered to achieve intentional failures at specific locations or faces or regions.

In some embodiments, defects (such as lower energy bonds) are intentionally engineered to ensure that the critical length or geometry of the final material has a specific strength to length or strength to volume ratio. These lengths can be tailored for specific end applications of the resulting carbon-resin composite.

Deliberately engineered defects result from regulating the growth of the carbon structure. Such regulation can be achieved by controlling reactor process conditions such as gas flow rate, residence time, flow velocity, Mach number, hydrocarbon concentration, etc. Other process conditions that can be controlled to regulate the growth of the lattice include plasma-specific conditions such as plasma concentration, thermal distribution gradient, disordered orientation within the plasma energy, ionization potential, collision frequency, microwave wave modulation, and microwave frequency.

These controls achieve specific types of localized structural growth and/or minimize the growth of carbon in particle orientation. As an example of regulating growth within the reactor: (1) when hydrocarbon atoms enter the plasma zone, they will begin to break C-H, C-C bonds in a specific and calculated manner; (2) when the molecules are broken into many C and H bonds, they become highly reactive; then (3) by adjusting the microwave energy in the reactor, the material is exposed to a higher (or lower) energy state. The higher (or lower) energy state corresponds to a preferred growth path. Based on the regulation of growth, a lattice with some relatively strong (or relatively weak) faces is formed. In post-processing, the resulting structured carbon decomposes along the weaker faces. As described above, the decomposition along the engineered weaker faces of the structured carbon promotes molecular combination with the polymer, resulting in a high-performance carbon-containing elastomer.

method

FIG. 12 shows a flow chart 1200 representing a method of producing a composite material according to some embodiments. The method includes producing a plurality of carbon particles in a plasma reactor in step 1210. In some embodiments, the plurality of carbon particles include 3D graphene, wherein the 3D graphene includes a porous matrix and graphene nanosheet particles in at least one form of: single-layer graphene (SLG), few-layer graphene (FLG), or multi-layer graphene (MLG). The method of FIG. 12 also includes: in-situ functionalizing the plurality of carbon particles in a plasma reactor in step 1220 to promote adhesion to a binder; and combining the plurality of carbon particles with a binder to form a composite material in step 1230.

In some embodiments, a plurality of carbon particles have a phase purity of graphene nanosheets greater than 99%. Carbon particles (such as GNP sub-particles) can have a 3D structure in the X-Y plane and in the Z direction, wherein the graphene nanosheet sub-particles are connected to each other to form a porous matrix. The 3D carbon particles can have sub-particles, such as GNP sub-particles, which are connected to each other by carbon-carbon bonds at multiple positions including edge-edge, edge-base face and base face-base face positions. The porous matrix includes gaps or spaces between sub-particles or within sub-particles (such as, between graphene nanosheet layers). For example, the porous matrix can include pores between graphene nanosheet sub-particles or pores between FLG or MLG layers.

In some embodiments, the fibers may be introduced into a plasma reactor in step 1240 for incorporation into a carbon-resin composite. In some embodiments, the fibers are modified, such as by etching, and used as a structure on which carbon particles are grown. For example, step 1240 may involve introducing a plurality of fibers into a plasma reactor (such as a microwave plasma reactor), modifying a plurality of fibers within a plasma or high temperature plume of the microwave plasma reactor, and growing a plurality of carbon particles on the plurality of modified fibers. In some embodiments, the fibers may be modified in a reactor different from the reactor in which the carbon particles are generated (such as before being input into a plasma reactor). In some embodiments, the carbon particles are 3D carbon, such as 3D GNPs grown on the fibers.

The generation of carbon particles in step 1210 can be carried out using a plasma reactor as described in Figures 1A-1B, and can also include using other reactors (such as thermal reactors) to provide energy for the growth of carbon particles. In some embodiments, the plasma reactor may be a high-frequency plasma reactor, and the high frequency is radio frequency (RF), very high frequency (VHF), ultra-high frequency (UHF) or microwave frequency. For example, the plasma reactor may be a microwave plasma reactor with a field-enhanced waveguide and a microwave energy source, wherein the field-enhanced waveguide is used as a reaction chamber in which a plurality of carbon particles are generated. The field-enhanced region has a reduced cross-sectional area between the first cross-sectional area and the second cross-sectional area of the field-enhanced waveguide, wherein the second cross-sectional area is less than the first cross-sectional area. The reaction zone is formed by a second cross-sectional area extending along the reaction length of the field-enhanced waveguide. The microwave energy source is coupled to the field-enhanced waveguide, and microwave energy is provided to the first cross-sectional area of the field-enhanced region, wherein the microwave energy propagates in the direction of the reaction length along the reaction zone. The microwave plasma reactor does not have a dielectric barrier between the field-enhanced region and the reaction zone. The method may include inputting hydrocarbon materials (e.g., gases, liquids) into a plasma reactor, and controlling parameters such as plasma mode, cracking temperature, and power level to control the growth rate, sub-particle and particle size and/or type of carbon grown in the reactor. The processing temperature in the reactor to produce the carbon material may be, for example, 3000K or higher, with a local temperature of 10,000K or higher.

The method may also include engineering defects into intentional defect locations in the carbon particles during the generation of the carbon particles in step 1210. Defects may be engineered by bombarding the carbon particles with atoms (such as by sputtering) to weaken bonds (such as carbon-carbon bonds) between sub-particles (such as edge-edge connections, edge-base planes, and/or base plane-base planes), wherein the bombardment may be controlled by aspects such as the injection pattern of the sputtered atoms, the gas particle pressure, the plasma parameters (such as the plasma concentration), and the microwave parameters (such as the wave modulation of the microwaves and the microwave frequency).

Functionalization of the carbon particles in step 1220 can include any of the methods and techniques described in the present disclosure. In some embodiments, the functionalization is performed in a plasma or high temperature plume of a plasma reactor. In some embodiments, the binder is a resin, and the plurality of carbon particles are functionalized to be compatible with the resin by promoting chemical bonding between the plurality of carbon particles and the resin. Embodiments can include, for example, adding functional groups to the carbon, performing surface doping or surface alloying, adding hardeners to the carbon particles, changing surface wettability, or performing surface treatment.

In some embodiments, the combination of carbon particles and a binder in step 1230 can be performed outside the reactor after the carbon particles are generated. In some embodiments, the combination of carbon particles and a binder can be performed in a reactor during or after the growth of carbon particles. In some embodiments, the method involves combining a plurality of functionalized carbon particles with a resin in a plasma reactor to form a composite material. In some embodiments, energy may be added to the composite material in step 1250 to further customize the properties of the composite material. For example, the method may include adding energy to the composite material during the combination of step 1230, wherein the plurality of carbon particles have an average starting particle size, and the energy causes the plurality of carbon particles to be reduced to an average final particle size less than the average starting particle size. The energy may be, for example, mechanical energy (such as, mixing), thermal energy, or high frequency energy. The method may also include, during the generation of carbon particles in step 1210, engineering defects to intentional defect locations in the carbon particles, wherein the average final particle size (in the addition of energy to the composite material in step 1250) is determined by the intentional defect locations.

13 shows a flow chart 1300 representing a method of producing a composite material according to some embodiments. The method includes: producing a plurality of carbon particles in a plasma reactor in step 1310; functionalizing the plurality of carbon particles in a plasma reactor to promote chemical bonding with a resin in step 1320; and combining the plurality of functionalized carbon particles with a resin within the plasma reactor to form a composite material in step 1330. The carbon particles can be combined directly with the resin in the reactor without contact with an external source or without manual contact with the resin or the carbon particles.

In some embodiments, the functionalization in step 1320 is performed in a plasma or high temperature plume of a plasma reactor. In some embodiments, the functionalization includes oxidation, nitridation, surface doping, surface alloying, or adding a hardener. Functionalization can include the embodiments described with respect to FIG. 12 and throughout this disclosure.

In some embodiments, step 1330 of combining carbon particles with resin in a reactor is performed in a plasma or high temperature plume of a plasma reactor. The combination of step 1330 may include embodiments described with respect to FIG. 12 and throughout this disclosure.

In some embodiments, the plasma reactor is a microwave plasma reactor, and the method of flowchart 1300 includes a step 1340 of introducing a plurality of fibers into the microwave plasma reactor and modifying the plurality of fibers within the plasma or thermal high temperature plume of the reactor, wherein the generation of step 1310 includes growing a plurality of carbon particles on the plurality of modified fibers. The addition of fibers may include the embodiments described with respect to FIG. 12 and throughout the present disclosure.

The carbon particles produced in step 1310 may include various allotropes, such as graphene, GNPs, MWSF, and CNTs, and may be 3D structured carbon materials including any of these allotropes. In some embodiments, the carbon particles include 3D graphene, wherein the 3D graphene has a porous matrix and has graphene nanosheet particles in at least one of the following forms: single-layer graphene (SLG), few-layer graphene (FLG), or multi-layer graphene (MLG). The graphene nanosheet particles grow in the X-Y plane and in the Z direction, wherein the graphene nanosheet particles are connected to each other. In an embodiment where GNPs are produced, the plurality of carbon particles may have a phase purity of graphene nanosheets greater than 99%.

In some embodiments, energy may be added to the composite material to further customize the properties of the composite material in step 1350. The addition of energy in step 1350 may include embodiments described with respect to FIG. 12 and throughout this disclosure.

The generation of carbon particles in step 1310, the functionalization in step 1320, and the combination in step 1330 can be performed using a plasma reactor as described in Figures 1A-1B, and can also include using other reactors (such as thermal reactors) to provide energy for the growth of carbon particles. As described with respect to Figure 12, in some embodiments, the plasma reactor may be a microwave plasma reactor having a field enhancement waveguide and a microwave energy source, wherein the field enhancement waveguide is used as a reaction chamber in which a plurality of carbon particles are generated. The field enhancement zone has a reduced cross-sectional area between the first cross-sectional area and the second cross-sectional area of the field enhancement waveguide, wherein the second cross-sectional area is less than the first cross-sectional area. The reaction zone is formed by a second cross-sectional area extending along the reaction length of the field enhancement waveguide. The microwave energy source is coupled to the field enhancement waveguide, and microwave energy is provided to the first cross-sectional area of the field enhancement zone, wherein the microwave energy propagates in the direction of the reaction length along the reaction zone. There is no dielectric barrier between the field enhancement zone and the reaction zone in the microwave plasma reactor.

In some embodiments, the method may include formulating a monomer or selecting a resin that is customized to accept a plurality of carbon particles. For example, a specific monomer or resin designed to bond to a specific type of carbon particle (such as graphene, CNO, CNT, and 3D structures of one or more of these) and/or to certain functional groups may be formulated.

Some embodiments include using plasma torch system to enhance the attachment of composite material of the present invention to surface (such as, metal substrate).For example, metal surface can be modified with the metal layer injected with carbon, and the metal layer is produced by plasma torch, to realize the high carbon content interface (such as, by metal fusion into carbon-polymer bonding) that carbon-polymer composite material can attach, so as to increase structural strength.The metal layer injected with carbon includes metal particles and carbon particles bonded together, which are generated by accelerating metal particles and carbon particles toward metal surface by high current by ionizing at least some of the particle atoms with the microwave plasma of plasma torch.Then, the carbon-metal particles produced are deposited on the metal surface, and melted together, producing the body injected on the composition, wherein the carbon-metal particles continue to deposit and melt together.Compared with the attachment of carbon-resin composite material with only metal surface, the metal surface of this carbon load improves the bonding of carbon-resin composite material and metal substrate.

Figure 14 shows that carbon-polymer composites can be used to produce an embodiment of an organometallic material. During the generation of carbon, metal can be integrated into or in a carbon structure, wherein the interface carbon is bonded to a metal lattice. That is, the carbon structure can be in the gap space of a metal lattice structure (such as a metal crystal structure, such as a face-centered cubic or body-centered cubic crystal structure). Metal and polymer can be fused together using such an organometallic structure, wherein various percentages of carbon material and metal can be used to produce a key between the metal and the polymer. Structure 1420 illustrates the use of such an organometallic material, wherein a carbon fiber layer 1422 crosses with an element 1424 (such as, during the manufacture of the final product, each layer is constructed in a cross manner). Element 1424 can be metal and/or can be made of an organometallic material having carbon in a crystal structure. Organometallic carbon-resin layer 1426 has a carbon-metal that is integrated into the resin to form a composite material, and layer 1426 is sandwiched between carbon fiber layers 1422 to provide a key between carbon fiber layers 1422 and element 1424. With this structure, the carbon-resin layer 1426 provides an intermediate between the element 1424 and the carbon fibers 1422 ; that is, by creating a transition from metal to carbon-metal to polymer and promoting adhesion between the materials of the structure 1420 .

As noted above, structured carbons that substantially conform to a specific regulated size, and/or a specific regulated pore size, and/or a specific regulated morphology, and/or a specific phase purity promote and/or affect improvements in composite materials containing these structured carbons. Strictly speaking, as an example, a high phase purity of carbon in a composite material results in a composite material having substantially higher performance than a composite material made with carbon of lower phase purity.

Figure 15 shows the results of using structured pure carbon. Specifically, the graph shows a region of very high values of the enhancement metric, where the high values correspond to the designed high purity level. Thus, the performance of the parts made using high purity structured carbon 1504 is significantly better than that of parts made using low purity carbon (such as, using N grade carbon 1502).

The aspect of being free of impurities can be quantified. Specifically, techniques such as those disclosed herein can produce free of impurities carbon to the extent that the carbon purity is 99% or higher. In some cases, the remaining 1% may contain various impurities, but no quantifiable impurities, at least to a purity level of 99%. One possible test to determine the total amount of impurities is to fully oxidize a sample and evaluate the influent stream. This is further described in ASTM E2550 and ASTM D1619.

The lower left portion of Figure 15 shows that lower grade carbons (such as conventional N-grade carbons) do not provide the desired level of reinforcement. This is because conventional N-grade carbons present less surface area to support molecular interactions with the polymer. As is known in the art, the higher the interaction between the polymer and the carbon (such as via site interactions, via available surface area, or via active surface area), the stronger the resulting polymer part.

One method of increasing the surface area of site interaction is to just increase the surface area of conventional carbon by milling or other mechanical treatment. However, in practice, when milling or other mechanical treatment is adopted, the impurity level increases, and therefore damages the cured elastomer. Strictly speaking, as an example, when sulfur is introduced (such as, as an unwanted impurity), the presence of sulfur inhibits curing. Incomplete or partial curing is accompanied by a reduction in crosslinking density, which in turn can lead to an observable reduction in the reinforcement system (such as, by a lower elastomer durometer measurement result, by a reduced bonded rubber, by a modified elongation at break, etc.). Merely increasing the surface area does not necessarily lead to an increase in the number of interaction sites. This is shown and discussed with respect to Figure 16A.

Relationship between surface area and interaction site volume

FIG. 16A shows a bounded region on a graph 1600 that relates the specific active area (SAA) of carbon (in any form) to a given specific surface area (SSA). As used herein, the specific surface area of a sample of a given material is defined as the total surface area of the sample of the same sample of the same material per unit mass. Thus, the unit is area/mass. As used herein, the specific surface area of a carbon structure is related to the geometry of the structure. As used herein, the specific active area (SAA) of carbon is the percentage of the corresponding SSA that is available for interaction (such as, interaction with a polymer, etc.). The accompanying drawings depict a desired region 1630 that is located above the graphene surface positive limit 1610 shown and to the right of the graphene surface positive limit 1620 shown.

The abscissa (X-axis) represents the range of SSA to a larger value corresponding to the theoretical limit of the surface area of the graphite particles, while the ordinate represents the range of SAA from 0% to 100%.

Intuitively, the specific active area of a sample of a given mass of material is defined as the total number of electrochemically active sites in the sample divided by the total number of electrochemically active sites that would be present in the same given mass of sample if the mass were composed entirely of single atoms of the given material. The value of the specific active area is therefore dimensionless and ranges from 0 to 1, or equivalently, 0% to 100%.

The graph depicts graphene sheets of different sizes. As shown, even if the specific surface area is substantially increased to a range of greater than 0 m2/g to about 2600 m2/g, no additional electrochemically active sites are formed, because the electrochemically active sites mainly appear only at the edges of the graphene sheets. Graphite particles are also shown in the graph 1600. As shown, as the size of the graphite particles decreases, they present more electrochemically active sites. However, there are empirical limits to the size of such graphite particles, and therefore, there are limits to the surface area presented by the graphite particles. This empirical limit is shown as the graphite surface active limit 1620.

On the one hand, graphene can present a very large surface area, but is limited to a relatively small range of corresponding electrochemically active sites. On the other hand, graphite can present a very large number of electrochemically active sites, but is limited to an upper limit on the surface area. Additional features are shown in Tables 1 and 2.

Table 1: Exemplary 2D graphene morphologies

Table 2: Exemplary 3D graphene morphologies

There is a need for 3D carbon morphology that exhibits a larger surface area than graphite and more active sites than 2D graphene. There is a need for technology to synthesize carbon structures in a reactor so that the morphology of the resulting carbon can be controlled and so that the resulting 3D carbon has a specific surface area and specific active area in the desired region 1630.

FIG16B1 depicts a system 1650 for synthesizing 3D carbon that is adjusted to correspond to a desired morphology. As shown, the microwave chemical processing reactor is configured to interface with a control system 1640. More specifically, the pressure at the supply gas inlet 302 and the process material inlet 310 is controlled by flow control 1641, the microwave energy source 304 is controlled by microwave pulse control 1642, the temperature in and around the FEWG 305 is controlled by temperature control 1644, and the back pressure at one or more outlets 303 is controlled by back pressure control 1645.

In addition to the aforementioned examples of adjustable reactor parameters 1646, multi-parameter control 1648 is also provided. Adjustable reactor parameters and multi-parameter control are used to create conditions within the reactor. When the desired carbon leaves from one or more outlets 303, they are collected in collector 1660, whereupon the carbon can be used to form a composite material. Further details on how morphology control 1643 operates are given in Figures 16B2 and 16B3.

FIG16B2 shows multi-parameter control (such as multi-parameter control 1648 ₁ and multi-parameter control 1648 ₂ ). Specifically, the figure shows specific surface area control 1647 and specific activity area control 1649. These multi-parameter controls can be used to adjust the morphology of the carbon obtained by the operation of the microwave chemical treatment reactor shown. More specifically, carbon structures exhibiting regulated specific surface area control and regulated specific activity area can be grown and assembled in the reactor, and after growth and assembly, the regulated morphology of the carbon is collected in a liquid collection facility 1661. The regulated morphology of the carbon mixed in the liquid can be subjected to additional energy input (such as microwave frequency, radio frequency or similar energy input).

In the particular embodiment shown, the additional energy input is provided as microwave energy input 1671. The specific frequency and energy amplitude of the microwave energy input 1671 can be controlled using microwave frequency and energy control 1653. The microwave frequency can be controlled so as to apply energy to the conditioned carbon mixed in the liquid without heating the liquid.

The liquid is specifically designed/selected to support specific chemistries. In this configuration, the carbon material can be suspended in a low loss tangential fluid so that highly localized heating of the aggregate material can be achieved, and microwave energy is provided to the collection facility to achieve thermal cracking of the matrix material for size reduction without damaging the morphological properties of the carbon material.

The choice and concentration of the dielectric loss tangent property can be adjusted to reduce the size of the suspended clumps without heating the fluid because the suspended clumps are held together by weak van der Waals or other weak forces and can therefore be easily broken into smaller clumps for subsequent dispersion.

Selective energy absorption by materials in the collection vessel can be used to force one type of material or fluid onto another, thereby (1) creating new particles or (2) depositing particles onto existing materials. In some cases, varying the frequency of the microwaves can result in a second layer being deposited onto a first layer, and so on. Controlled sequential application of energy to the collection vessel can result in the deposition of multiple layers of successively deposited material.

In the embodiment of Figure 16B2, the specific surface area of the resulting carbon structure and the specific active area of the resulting carbon structure can be independently controlled by independent settings of specific surface area control 1647 and specific active area control 1649. However, in some embodiments, the morphology of the carbon can be controlled by using multi-parameter control that coordinates the settings of specific surface area control 1647 with the settings of specific active area control 1649.

Figure 16B3 shows a morphology selection technique 1670 implemented by one or more controls. The morphology control 1643 shown can be used to coordinate the control of any one or more of the aforementioned adjustable reactor parameters 1646 (such as flow control 1641, microwave pulse control 1642, temperature control 1644, back pressure control 1645, etc.) to adjust the conditions within the reactor to promote specific growth and assembly processes within the reactor.

Morphology control is used to coordinate any/all of flow control 1641, microwave pulse control 1642, temperature control 1644, and back pressure control 1645 to create conditions within the reactor that are conducive to the formation of a specific desired morphology. Strictly speaking, as an example, morphology control 1643 can adjust the conditions within the reactor to promote specific growth and assembly processes within the process material stream 311b.

As shown, the morphology control 1643 can be adjusted to any point within the entire range from a minimum value (such as, the "minimum value" shown) to a maximum value (such as, the "maximum value" shown). When set to the minimum value, the conditions in the reactor are conducive to the formation of flat graphene sheets 1651. When set to the maximum value, the conditions in the reactor are conducive to the formation of small graphite particles. Throughout the range, other settings produce different morphologies. For example, the conditions in the reactor can be adjusted to facilitate the formation of graphite particles with a size between the larger graphite particles 1656 shown and the smaller graphite particles 1658 shown.

In a particular configuration, the settings for morphology control 1643 may correspond to creating intra-reactor conditions conducive to producing 3D carbon structures exhibiting a particular pore matrix and/or a particular fractal dimension tuned for a particular application, such as for battery applications, for elastomeric systems, for organometallic systems, etc. In another particular configuration, the settings for morphology control 1643 may correspond to creating intra-reactor conditions conducive to producing 3D carbon exhibiting scaffold structures and tuned fractal dimensions, such as for resin-based composite applications.

Creation and use of crumpled graphene sheets

In yet another particular configuration, the configuration of the morphology control 1643 can correspond to creating in-reactor conditions that facilitate the production of "corrugated" (referring to intentionally or purposely organized or disrupted folding, compression, or some other type of orientation or configuration that facilitates exposure of additional active surface per unit volume compared to conventional substantially straight or curved graphene sheet configurations, alternatively, the term may also include "crumpled," "compressed," "compacted," "wavy," etc.) graphene sheets 1652 that are particularly useful in thermoplastic and thermoset composites. These corrugated graphene sheets 1652 are significantly different from the other morphologies shown. Using the corrugated graphene sheets 1652, the properties of the thermoplastic and thermoset composites are significantly improved.

These wrinkled graphene sheets 1652 appear to be beneficial for thermoplastic materials, in part because stress buildup caused by the mismatch in coefficient of thermal expansion (CTE) between the thermoplastic and the filler is lower when the polymer is mixed with the wrinkled graphene sheets.

Generation and use of ordered carbon scaffolds

[00136] Referring to yet another setting of morphology control 1643, multiple reactor parameters can be coordinated to create conditions within the reactor that are conducive to the formation of ordered carbon scaffolds of varying morphological order.

One way to characterize an ordered carbon scaffold is by using a fractal dimension metric. And one way to calculate a fractal dimension metric is by using a "box counting" method. Specifically, and as used herein, the fractal dimension is derived by observing a certain area overlapped by a box of a certain size (box size). This fractal dimension is an indicator of shape complexity and surface irregularity. Larger fractal dimensions indicate more complex irregularities. The fractal dimension is defined by the following formula, where N _δ (F) is the number of square boxes of size δ required to cover the pattern F.

To apply this equation to SEM images, a cross-sectional SEM image of a scaffold composed of voids and carbon is divided into grid regions (such as boxes) at regular intervals of size δ, and the number of boxes containing voids is counted. The value of δ is then changed (such as halved), and the SEM image is again divided into grid regions with edges of δ. A double logarithmic plot is created, in which the number of boxes with voids counted is plotted on the vertical axis, and different sizes of δ are plotted on the horizontal axis. The fractal dimension mentioned above is determined by the slope of the curve on the double logarithmic plot.

FIG16B4 shows a schematic diagram of the morphology of a wrinkled sheet consisting of flat crystallites of various lengths (such as La1, La2, etc.) fused together at sheet folds (such as Fold 1, Fold 2, Fold 3, Fold 4, Fold 5). La is the average crystallite size estimated from Raman spectroscopy. The sheet shown has edges at Edge 1 and Edge 2.

Figure 16C1 shows the relationship between the average crystallite size La of the D and G bands and the D:G intensity ratio in the Raman spectra of several wrinkle morphologies compared to the reference. Figure 16C2 shows the relationship between the average crystallite size La of the 2D and G bands and the 2D:G intensity ratio in the Raman spectra of several wrinkle morphologies compared to the reference. Details of the data points on the graphs of Figures 16C1 and 16C2 are presented in Table 3.

Table 3: Comparison of Raman measurement results

The G peak corresponds to the first-order scattering of the sp2 domain (such as, due to the in-plane vibration of the carbon atom). In contrast, the D peak is attributed to the disordered region containing sp3 carbon with related out-of-plane vibration. The D/G intensity ratio of the D band and the G band in the Raman spectrum reflects the ratio of the disordered region with sp3 hybridized carbon to the two-dimensional atomic scale hexagonal lattice domain consisting of sp2 hybridized carbon. For the graphene of the wrinkled morphology, the disordered region is related to the folding in the graphene sheet structure. Therefore, the D:G intensity ratio of the graphene of this type of wrinkled morphology reflects the wrinkle degree of the graphene sheet.

The size of the hexagonal lattice domains composed of sp2 hybridized carbon or the crystallite size La can be estimated from the D:G intensity ratio. For graphene with wrinkled morphology, the D:G intensity ratio reflects the size of the domains with flat sheet morphology between the disordered regions where folding occurs. The larger in-plane size of the sp2 domains with lower D:G ratios indicates a wrinkled morphology with less folding.

Referring to Figure 16C1, it shows a group of graphene materials (wrinkle A, wrinkle B, wrinkle C) with different roughness of graphene sheets obtained by adjusting the production conditions as described above. It shows that the D/G ratio decreases linearly with the increase of crystallite size, indicating that the wrinkle A material has fewer folds formed on the sheet compared with other materials.

In contrast, the values for the reference graphene do not follow the same trend of decreasing D/G ratio with increasing La. This reference material, with larger crystallite size La compared to the wrinkled A material, is characterized by a higher D/G ratio than the wrinkled A material, indicating a different morphology with increasing disorder in the graphene sheets.

The 2D band of the Raman spectrum is considered to be an overtone of the D peak. It is known that the intensity ratio of the 2D mode peak to the G mode peak (such as the 2D/G intensity ratio) is related to the number of layers in graphene. A higher 2D/G intensity ratio corresponds to fewer layers in a multilayer graphene material.

Referring to Figure 16C2, there is shown the relationship between the average crystallite size La and the 2D:G intensity ratio of the 2D and G bands in the Raman spectra of several wrinkle morphologies compared to a reference. The 2D/G ratio increases linearly with increasing crystallite size, indicating that larger crystallites are formed as fewer layers fuse together to form sheets. The figure shows that the wrinkle morphology can be adjusted by producing conditions between the less folded wrinkle A material composed of fewer layers with the largest crystallite size La (highest 2D/G ratio) and the more folded wrinkle C material composed of more layers with the smallest crystallite size La (lowest 2D/G ratio).

The reference graphene material having a larger crystallite size La than the wrinkle A material is characterized by a higher 2D/G ratio than the wrinkle A material, indicating a sheet morphology with larger crystallites and even fewer layers. However, this reference material composed of graphene layers with a larger disorder (e.g., a higher D/G ratio) is as described above and shown in Figure 16C1.

There are many techniques for combining morphologically modified carbon with thermoplastics and/or thermosetting epoxies. One particular process flow for combining morphologically modified carbon with thermoplastics and/or thermosetting epoxies is shown in FIG. 17A.

FIG. 17A shows a process flow 1700 for processing carbon material from a reactor and delivering the composite material for downstream processing. As shown, conditioned carbon 1701 is input into the process (step 1702). The carbon is processed to achieve a specified particle size and/or a specified active area (step 1706) followed by chemical capping 1710 or coating 1708. The process of achieving the specified particle size and specified active area is based at least in part on post-processing specifications 1705, which may include one or more of a surface area specification, an active area specification, and/or a particle size specification.

If a process is being performed to obtain a reinforced thermoplastic material, the process continues through step 1712. If a process is being performed to obtain a reinforced thermosetting polymer, the process continues through step 1714. However, in both cases, the process includes processes known in the art for producing one or more of carbon fiber (CFRES), glass fiber (GF), acrylic fiber (AF) reinforced composite materials, or combinations thereof (such as process 1716). The illustrated process ends with a product 1718 (such as a reinforced thermoplastic material or a reinforced thermosetting material) that can be used for various applications (such as including but not limited to prepreg applications, molding applications, extrusion processes, etc.).

The material may be subjected to shear forces (such as during particle processing 1706 and during mixing) while undergoing process flow 1700. Additionally, the material may undergo cooling while undergoing process flow 1700. The effects of applying shear forces to the material and the effects of cooling are as shown and described with respect to FIG. 17B.

Figure 17B shows a schematic diagram 1750 showing how polymer chains and carbon structures interact when subjected to shear force input and cooling. Specifically, and as shown in the figure, when carbon structures (such as, graphene sheets) are mixed with resins, polar groups at the edges of the carbon structures are usually combined with polar groups of resins via hydrogen bonding or other types of bonding. Under the shear force applied to the blend (such as, when grinding), the aggregates of carbon materials are broken into smaller aggregates, and are reduced to the level of a single sheet. For example, and as shown in the figure, the high-energy graphene surface newly exposed to the resin is combined with polymer segments via van der Waals interactions, so they are fixed on the surface. During this treatment, polymer segments are aligned with the surface of the carbon structure. For flat sheet morphology, this alignment occurs in the extended region, resulting in the fixation of long polymer segments. However, for wrinkle morphology, due to the change in the face orientation of the folding sheet, alignment occurs in the much shorter region between the folding of the sheet, resulting in a shorter length of the polymer segments combined with the surface. Therefore, the wrinkle sheet morphology causes the shorter length of the fixed polymer segments.

Fixed segments on the surface of carbon structures have a significant impact on the stress accumulation of thermoplastic materials. As an example, after the thermoplastic material is blended with the graphene material at a temperature higher than the transition temperature of the thermoplastic material (Tg, meaning the glass temperature of amorphous plastics, or Tc, meaning the crystallization temperature of crystalline plastics), the prepared composite blend is placed in a mold and then cooled to a temperature lower than the aforementioned transition temperature to solidify the composite material. The coefficient of thermal expansion (CTE) is a measure of the volume change of a material when it passes through a transition temperature. The polymer matrix expands when it is higher than its transition temperature and shrinks when cooled. This leads to the rearrangement of the segments, tending to the equilibrium chain conformation. However, if the polymer segments are fixed on the surface of the carbon structure, they cannot promote rearrangement, and therefore keep stretching in a non-equilibrium conformation. The rest of the thermoplastic matrix shrinks around the carbon structure, thus generating a local compression force. However, the carbon structure does not shrink when cooled. The mismatch of the CTE of this thermoplastic material and the carbon structure leads to undesirable stress concentration at the graphene/polymer interface.

As described above and with specific reference to the case of flat sheet-like carbon structure morphology, long polymer segments are undesirably pinned on extended areas. Therefore, it leads to undesirable large stress concentration areas formed under cooling below the transition point. In contrast, according to the wrinkled graphene sheets disclosed herein, and due to (1) the shorter length of the fixed polymer segments, and (2) due to the redistribution of the polymer segments on the surface of the wrinkled graphene sheet. Therefore, the wrinkled graphene sheet morphology serves to reduce the size of the stress concentration areas and redistribute them over a larger volume. This in turn minimizes the propagation of stress cracks under deformation, which in turn results in improved mechanical properties of the resulting polymer-containing composite material.

Some such improvements in the mechanical properties of the resulting polymer-containing composites are shown and discussed with respect to Figures 18A and 18B.

Improvement of mechanical characteristics of thermoset material samples

FIG. 18A and FIG. 18B show DMA analysis of samples compared to reference composites. DMA analysis includes viscoelasticity and glass transition temperature of the cured system as a function of temperature. FIG. 18A shows the improvement in storage modulus relative to the reference sample when using the carbon of the present disclosure. Specifically, and as shown, sample 1 exhibits a flexural (storage) modulus of about 3.0 GPa, which is a 50% improvement in flexural (storage) modulus at 50°C compared to the pure epoxy reference sample. Sample 2 also exhibits an improvement of about 50% in flexural (storage) modulus at 50°C compared to the pure epoxy reference sample, and this improvement is present to varying degrees over a wide temperature range (at least up to about 100°C). However, while sample 1 and sample 2 have almost similar storage moduli at the beginning of the test, sample 1 subsequently begins to deform earlier and shows a lower linear viscoelastic range as the temperature ramp increases compared to sample 2. This is because sample 2 has a stronger filler/resin surface interaction due to better dispersion of carbon particles in the resin. This improved dispersion quality of the 3D carbon disclosed herein is due to increased compatibility with the resin, resulting in stronger resin/carbon interfacial phase interactions.

FIG. 18B shows the change in glass transition temperature, referred to as Tg, relative to the reference sample when using the carbon of the present disclosure. The higher Tg of sample 2Tg(2) is associated with a higher crosslink density and lower free volume and uniform dispersion of carbon particles in the matrix. These factors restrict the movement of the polymer chains and require higher temperatures to provide sufficient kinetic energy for the polymer segments to change conformation. However, the lower Tg of sample 1Tg(1) may be the result of a plasticizing effect or poor dispersion of carbon in the matrix. Covalent, ionic or van der Waals-bound steric stabilizing ligands at the graphene surface in the form of only a few carbon atoms in length (n=about 5 to about 9) are bonded to oligomeric substances of about 10 to about 20 carbon atoms in length will result in improved dispersion stability, miscibility with epoxy resins, and improved degree of cure. However, such steric stabilizers may soften the resin, thereby effectively reducing the Tg transition. On the other hand, the same decrease in Tg may be the result of poor carbon dispersion quality, because carbon aggregates with loosely bound carbon particles are more easily deformed under applied stress than composite systems with strong bonding between the resin and the carbon particles.

As shown in Figure 18B, and particularly applicable to Sample 2, improving both E' (storage modulus) and Tg requires a combination of good dispersion quality, minimized plasticizing effects (if a steric stabilizer is used), high crosslinking, and low free volume. Sample 2 exhibits an improved operating range compared to the pure epoxy reference sample. This is because the 3D carbon disclosed herein achieves increased compatibility of the resin/catalyst/fiber interaction, which in turn results in a densely crosslinked thermosetting composite in which the carbon is optimally dispersed within the composite to increase (or in some cases, maximize) the resin/carbon/fiber interfacial phase interaction.

Figure 18C1 shows the improvement in compressive strength and flexural strength relative to a reference sample when using the carbon disclosed herein. Specifically, it represents an example of a carbon fiber reinforced epoxy resin composite material, wherein the carbon fiber material has a medium modulus 7 (IM7) 6,000 (6k), a yarn count plain weave (PW) of 200 grams per square meter (gsm) of fabric average weight (F.A.W.), and a resin content (RC) of 35% by weight. As shown in the figure, the composite material named "Epoxy-Crinkle" exhibits improved compressive strength and flexural strength compared to the "pure epoxy" reference sample. This is because the 3D carbon disclosed herein achieves increased compatibility with resins, catalysts, and fibers, resulting in improved interactions.

Figure 18C2 shows the improvement of interlaminar shear strength (ILSS) and bending strength relative to the reference sample when using carbon disclosed in the present invention. Specifically, and as shown in the figure, respectively, the composite material made of carbon named as fold 1 shows an improvement of several percentages of interlaminar shear strength (ILSS) and bending strength, while the composite material made of carbon named as fold 3 shows an improvement of 5% to 12% of ILSSS and bending strength, and the composite material made of carbon named as fold 5 shows an improvement of 12% to 20% of ILSSS and bending strength. This is because the 3D carbon disclosed herein achieves an increase in the compatibility of resin/catalyst/fiber interactions, which in turn leads to an improvement in energy dissipation between carbon fiber and polymer. This increased adhesion allows a variety of composite material properties (such as bending, ILSS, compression, etc.) to occur within the same system. The improvement may be directly related to the morphology (such as wrinkle features) of graphene, which in turn is caused by the setting of the aforementioned adjustable reactor parameters.

Improvement of mechanical characteristics of thermoplastic material samples

FIG. 19A shows the improvement in mechanical characteristics of thermoplastic material samples associated with the selection of carbon having a specific fractal dimension. Specifically, the specific strength of the resulting thermoplastic material is highly correlated to the fractal dimension of the carbon added to the nylon system. In the first improved embodiment shown, a corrugated type 3 carbon with a fractal dimension of approximately >2.5 was added to the nylon system. In the second improved embodiment shown, a corrugated type 5 carbon with a fractal dimension of approximately >2.5 was added to the nylon system. The first improved embodiment exhibited a specific strength of 100 MPa/g, while the second improved embodiment exhibited a specific strength of 108 MPa/g. For reference, the control nylon system had a specific strength of 75 MPa/g, while the prior art material was added to increase the strength to approximately 82 MPa/g.

Figure 19B1 shows that the bending modulus improves as the carbon loading volume increases. The increase in bending modulus is directly related to good dispersion. That is, if the dispersion quality is good, then the fixed material additive that has a specific modulus (and other characteristics) added to the lower modulus system will increase the modulus of the total system. In addition to the first-order modulus of the filler material (such as graphene), the key attribute is the dispersion quality of the material. In the case of insufficient dispersion, the high modulus material added to the lower modulus material will not show a significant increase in modulus. As can be seen from Figure 19B00, among the three materials added, the dispersion quality of wrinkle 3 shows excellent dispersion at higher loads. At a load of about 5%, wrinkle 1 shows excellent dispersion, and the platform shows that the interface site between graphene and the polymer is saturated, such as, an active surface area is set for the added material, and no modification is performed during the process.

Figure 19B2 shows that flexural strength improves with increasing carbon loading volume. The improvement in strength is particularly related to surface interactions, i.e., graphene/graphene-type surfaces and/or combinations thereof (or other materials) interact well with the polymer. The interactions that may occur can be, but are not limited to, physical and/or chemical attractions. In this figure, wrinkle 1 shows the highest increase in flexural strength due to its excellent surface interactions and minimal aggregation within the nylon system. The linear behavior of wrinkle 2 is directly related to the scaling of the surface area available for interaction with the specific polymer system, and it also shows minimal aggregation. The degree of strength increase varies with the modulus of the additive material.

FIG. 19C shows the improvement in tensile strength relative to the reference sample when using the carbon of the present disclosure. Specifically, and as shown, the tensile strength of the composite material is improved by about 15% compared to the reference sample using the Pleated 5 carbon. This increase is related to the dispersion quality of the material. If the dispersion quality is poor, additional voids and stress concentration sites will be added to the system, limiting the tensile strength. In addition, the increased heat dissipation of Pleated 5 changes the cooling rate of the nylon system and causes the polymer to recrystallize, showing an increase in tensile strength.

Figure 20 shows a system 2000 for producing carbons of a specified morphology and using them in a composite material system. Specifically, the system of Figure 20 illustrates aspects related to producing carbonaceous materials conforming to a selected morphology.

In the exemplary system shown, a hydrocarbon feedstock 2010 is fed into a reactor 2002. The reactor is controlled in whole or in part by a carbon morphology parameter value 2006 corresponding to a resultant specification 2004, which is determined in whole or in part by a selector 2008. The selector 2008 may be controlled by a user, and/or may be controlled by a process recipe, and/or may be controlled by a set of one or more application-specific terminal component specifications. The reactor produces structured carbon 2050, which may be in the form of carbon in form 1 2052, or form 2 2054, or form 3 2056, and/or any combination thereof. The specific characteristics of the structured carbon 2050 may be controlled in whole or in part by the aforementioned adjustable reactor parameters 1646 (see FIG. 16B1).

High purity/sulfur-free carbon

The aforementioned carbon structure does not have a residual sulfur content. This feature is different from charge grade carbon black because, unlike charge grade carbon black, the aforementioned carbon structure is not derived from oil. In addition, even though thermal grade carbon black is derived from natural gas, the aforementioned carbon structure is also different from thermal grade carbon black. When used in various applications, the aforementioned carbon structure performs better than thermal carbon black. Specifically, thermal black carbon exhibits poor reinforcement and tensile structural properties when used in elastomer applications, while the aforementioned carbon structure exhibits improved reinforcement and tensile structural properties when used in elastomer applications.

The structured carbon is combined in various forms of material processing step 2012. Strictly speaking, as an example, post-processing can include mixing the structured carbon with other materials (such as, mixing with application-specific materials), and/or post-processing can include mixing the structured carbon using a large number of post-processing techniques (such as, application-specific post-processing techniques). In some cases, the structured carbon changes during post-processing. For example, the structured carbon may shear during mixing. The ability to engineer structured carbon materials to adapt to specific adjustable morphologies is dominant in producing the improvements discussed herein.

In the illustrated system 2000, the results of such post-processing may include final components 2016 (e.g., resulting component 1, resulting component 2, ... resulting component N). Some or all of the final components are analyzed to determine resulting characteristics. Strictly speaking, as an example, the resulting characteristics of the final components 2016 may include exhibiting extremely high enhancement (e.g., in the illustrated high enhancement region 2070).

The foregoing system can support a number of processes or formulations. In an exemplary embodiment, the steps include: (1) treating a hydrocarbon gas in a reactor to produce hydrogen and structured carbon (e.g., wherein the structured carbon is at least 99% free of elements other than carbon or hydrogen), and (2) introducing the structured carbon into a mixture of additional materials to produce a composite material. In some formulations, the mixture of additional materials includes any one or more of a polymer, a filler, a curing agent, or a receptor.

In some treatment schemes, the structured carbon has at least one adjusted fracture surface. Such structured carbon with adjusted fracture surface is mixed with additional materials, and its amount and formulation are controlled at least in part based on the application-specific final component specifications. In addition, the specific fracture surface of the structured carbon can be controlled during the treatment in the reactor. Strictly speaking, as an example, by controlling the conditions in the reactor, the structured carbon produced can be adjusted to have a fracture surface engineered for a specific final product feature. For example, in a formulation, the structured carbon produced in the reactor 2002 is deliberately not compressed before being used for post-processing.

In some engineered formulations, the fracture plane between molecules is defined by the presence or absence of bonding/non-bonding carbon atoms. The fracture plane can be engineered by introducing weakly bonded regions into the lattice, by introducing gaps or holes or by introducing dangling bonds. These weakly bonded regions can be intentionally caused by introducing non-carbon chemicals into the system to form different bonds. For example, by introducing a measured amount of oxygen into the reactor during the formation of structured carbon, a weaker C-O bond (such as, weaker than a C-C bond) can be formed in the lattice. Due to the different energies associated with each type of bond, the flat structure of the lattice can be engineered to achieve intentional failures at specific locations or faces or regions.

Although in some formulations defects are removed, in some formulations such as those described above, defects (such as low energy bonds) are intentionally engineered to ensure that the critical length of the final material has a specific strength to length ratio. The intentionally engineered defects are caused by regulating the growth of the carbon structure. This regulation can be achieved by controlling process conditions such as gas flow rate, residence time, flow velocity, Mach number, hydrocarbon concentration, etc. Other process conditions that can be controlled to regulate the growth of the lattice include plasma-specific conditions such as plasma concentration, thermal distribution gradient, random orientation within the plasma energy, ionization potential, collision frequency, microwave wave modulation, and microwave frequency.

These controls enable specific types of localized structural growth and/or minimize the growth of carbon in a particle orientation. As an example of regulating growth within a reactor: (1) When hydrocarbon atoms enter the plasma zone, they will begin to break C-H, C-C bonds in a specific and calculated manner; (2) When the molecules are broken into many C and H bonds, they become highly reactive; then (3) by regulating the microwave energy in the reactor, the material is exposed to a higher (or lower) energy state. The higher (or lower) energy state corresponds to a preferred growth path. Based on the regulation of growth, a lattice with some relatively strong (or relatively weak) faces is formed. In post-processing, the resulting structured carbon decomposes along the weaker faces. The decomposition along the engineered weaker faces of the structured carbon promotes molecular combination with the polymer, resulting in a high-performance carbon-containing elastomer.

Other Implementations

Embodiment A is a composite material comprising: (i) a polymer; (ii) additional reinforcement (such as, fibers); and (iii) a graphene-containing material mixed into the polymer, wherein the graphene-containing material exhibits a specific surface area of at least 20 m2/g and a specific active area of at least 2% of the specific surface area.

In a variation of embodiment A, the composite material exhibits a tensile strength greater than 300 megapascals. In a variation of embodiment A, the composite material exhibits a compressive strength greater than 400 megapascals. In a variation of embodiment A, the composite material exhibits a flexural strength greater than 400 megapascals. In a variation of embodiment A, the composite material exhibits an in-plane shear strength less than 200 megapascals. In a variation of embodiment A, the composite material exhibits an interlaminar shear strength greater than 25 megapascals. In a variation of embodiment A, the composite material exhibits a flexural modulus greater than 50 gigapascals. In a variation of embodiment A, the composite material exhibits improvements in mechanical, thermal, or electrical properties compared to a composite material in the absence of the graphene-containing material.

Embodiment B is a composite material comprising: (i) a polymer; (ii) additional reinforcement (such as, fibers); and (iii) a graphene-containing material mixed into the polymer, wherein the graphene-containing material exhibits a specific surface area of at least 40 m2/g and a specific active area of at least 4% of the specific surface area.

In a variation of embodiment B, the composite material exhibits a tensile strength greater than 300 megapascals. In a variation of embodiment B, the composite material exhibits a compressive strength greater than 400 megapascals. In a variation of embodiment B, the composite material exhibits a flexural strength greater than 400 megapascals. In a variation of embodiment B, the composite material exhibits an in-plane shear strength less than 200 megapascals. In a variation of embodiment B, the composite material exhibits an interlaminar shear strength greater than 25 megapascals. In a variation of embodiment B, the composite material exhibits a flexural modulus greater than 50 gigapascals. In a variation of embodiment B, the composite material exhibits improvements in mechanical, thermal, or electrical properties compared to a composite material in the absence of the graphene-containing material.

FIG. 21 depicts various properties of thermoplastic and thermoset materials used in the applications shown. The properties shown include mechanical properties, thermal conductivity, oxidation resistance, durability, resistance to high temperature softening, fatigue resistance, and electrical conductivity. Individual parameters and/or combinations of these parameters dominate when selecting a specific thermoplastic or thermoset material for a particular application.

Strictly speaking, as an example, oxidation resistance may be the primary parameter when selecting a thermoplastic or thermoset material for manufacturing a corrosion resistant valve. As another example, mechanical properties such as strength to weight ratio may be the primary mechanical properties when selecting specific thermoplastic and thermoset materials for manufacturing aircraft components. The component may also need to exhibit very high resistance to system fatigue.

Typically, thermoplastics and thermosetting materials not only exhibit the aforementioned properties, but also have lower densities than alternative materials. Compared to the same parts made of the same thermoplastic material without carbon loading, the lower density of the carbon-loaded thermoplastic material generally corresponds to a lower weight of the molded part. Therefore, truck parts (such as cab parts, as shown), automotive parts (such as door fenders, roof panels, etc.), motorcycle parts, bicycle parts, and various parts (such as structural members) of air vehicles, and/or ships, and/or space-based aircraft or platforms can take advantage of the lower weight-to-strength ratio of the thermoplastic material and thermosetting material of the present disclosure.

As another example, thermoplastics and thermosets generally exhibit exceptionally low thermal conductivity, making structural members formed from thermoplastics and thermosets useful in high temperature applications requiring thermal insulation (such as heat sinks for electronic devices, industrial heat exchangers, etc.).

In certain embodiments, one set of properties may dominate other properties. For example, the surface of a space-based vehicle (such as a satellite) may need to be highly reflective to a certain range of electromagnets, while at the same time, the surface of the space-based vehicle may need to be thermally insulated (such as non-conductive). The aforementioned tuning techniques accommodate such situations, where a particular desired property (such as reflectivity) dominates the tuning of the microwave reactor in order to produce a substantially reflective surface, even at the expense of other properties.

The properties as shown and described with respect to Figure 21 are merely examples. Additional properties and/or combinations of properties may be needed or desired in various applications, and these additional properties are manifested in the resulting material based on adjustments to the input and control of the microwave reactor. Strictly speaking, as examples of the aforementioned additional properties, such properties and/or combinations of properties may include or be related to strength to weight ratio, and/or specific density, and/or mechanical toughness, and/or shear strength, and/or bending strength, etc. In addition, in embodiments of the present disclosure, the processing steps and materials obtained by the combination of a thermal reactor and a microwave reactor can achieve further high-value material properties.

Additional embodiments include injection molding of 3D carbon-resin materials. Such embodiments include injection processing of composite 3D carbon matrix materials, injection processing of functionalized 3D carbon matrix materials, and injection processing of functionalized 3D carbon matrix materials mixed with nanomaterials. Other embodiments include functionalized 3D carbon matrix materials in energy storage devices, such as those used in high-capacity batteries, high-efficiency fuel cells, and high-efficiency flow batteries.

In summary, the present invention particularly relates to the following aspects:

<1>. A composite material comprising:

a polymer comprising a filler configured to distribute one or more areas of stress concentration of the composite material over one or more corresponding larger areas of the composite material; and

A graphene-containing material is at least partially mixed into the polymer based on wrinkles of the graphene-containing material, in one or more exposed surfaces of the polymer, wherein the wrinkles are configured to increase bonding between the polymer and the graphene-containing material.

<2>. The composite material according to <1>, wherein the filler comprises a plurality of carbon fiber layers intersecting the organic metal material.

<3>. The composite material according to <2>, wherein the intersections between the plurality of carbon fiber layers and the organic metal material form an interconnected matrix configured to reinforce the composite material.

<4>. The composite material according to <1>, wherein the graphene-containing material has a specific surface area of at least about 60 m ² /g, and at least 10% of the specific surface area of the graphene-containing material is incorporated into the polymer.

<5>. The composite material according to <1>, wherein the composite material has a storage modulus of at least about 2.5 GPa at about 50°C.

<6>. The composite material according to <1>, wherein the composite material has a maximum tan δ greater than about 0.25.

<7>. The composite material according to <1>, wherein the composite material has a glass transition temperature higher than about 30°C.

<8>. The composite material according to <1>, wherein the graphene-containing material has a fractal dimension greater than about 1.0.

<9>. The composite material according to <1>, wherein the graphene-containing material comprises approximately 2 to 25 graphene sheets.

<10>. The composite material according to <1>, wherein the graphene-containing material has a D/G ratio of Raman band intensity between approximately 0.3 and 1.

<11>. The composite material according to <1>, wherein the graphene-containing material contains less than about 10% of oxygen-containing species.

<12>. The composite material of <1>, wherein the graphene-containing material has a particle size comprised between less than about 0.1 and about 1.0 micrometers.

<13>. The composite material as described in <1>, wherein the graphene-containing material comprises one or more wrinkled graphene sheets.

<14>. The composite material as described in <13>, wherein the corresponding wrinkled graphene sheet comprises a plurality of crystallites that are fused together at corresponding folds in the corresponding wrinkled graphene sheet.

<15>. The composite material of <14>, wherein the crystallites have a size of less than about 24 nanometers.

It should be understood that those of ordinary skill in the art can easily think of changes, variations and equivalents of these embodiments after reading this disclosure. For example, a feature shown or described as part of one embodiment can be used together with another embodiment to produce yet another embodiment. Therefore, the subject matter of the present invention is intended to cover all such modifications and changes within the scope of the appended claims and their equivalents. Without departing from the scope of the present invention, those of ordinary skill in the art may practice these and other modifications and changes to the present invention, and the scope of the present invention is more specifically set forth in the appended claims. In addition, those of ordinary skill in the art will understand that the foregoing description is exemplary only and is not intended to limit the present invention.

Claims (12)

1. A composite material, comprising:

A thermosetting polymer;

A filler; and

A graphene-containing material having a specific surface area of at least 60m ²/g, and being dispersed in the thermosetting polymer,

Wherein the composite is characterized by: the flexural modulus of the composite material was improved by 50% compared to the flexural modulus of the thermosetting polymer in the absence of the graphene-containing material.

2. The composite material of claim 1, wherein the filler comprises a plurality of carbon fiber layers intersecting an organometallic material.

3. The composite of claim 1, wherein the improvement in flexural modulus is measured at a temperature of 60 ℃ to 100 ℃.

4. The composite material of claim 1, wherein the composite material has a maximum tan delta greater than 0.25.

5. The composite material of claim 1, wherein the composite material has a glass transition temperature above 30 ℃.

6. The composite material of claim 1, wherein the graphene-containing material comprises 2 to 25 graphene sheets.

7. The composite material of claim 1, wherein the graphene-containing material has a D/G ratio of raman band intensities between 0.3 and 1.

8. The composite material of claim 1, wherein the graphene-containing material contains less than 10% oxygenates.

9. The composite material of claim 1, wherein the graphene-containing material has a particle size of less than 1.0 microns.

10. The composite material of claim 1, wherein the graphene-containing material comprises one or more sheets of pleated graphene.

11. The composite of claim 10, wherein respective sheets of pleated graphene comprise a plurality of crystallites fused together at corresponding folds in the respective sheets of pleated graphene.

12. The composite material of claim 11, wherein the crystallites have a size that is less than 24 nanometers.