CN108069725B

CN108069725B - A kind of hollow foam material and its preparation method and application

Info

Publication number: CN108069725B
Application number: CN201611001541.1A
Authority: CN
Inventors: 张劲松; 高勇; 田冲; 杨振明; 杨晓丹; 矫义来
Original assignee: Institute of Metal Research of CAS
Current assignee: Institute of Metal Research of CAS
Priority date: 2016-11-09
Filing date: 2016-11-09
Publication date: 2021-05-18
Anticipated expiration: 2036-11-09
Also published as: CN108069725A; WO2018086522A1

Abstract

本发明涉及多孔材料领域，具体地说是一种中空泡沫材料及其制备方法和应用。该中空泡沫材料在宏观上由三维连通的支撑骨架网络构建而成，支撑骨架自身为三维连通的具有中空结构的微通道，微通道管壁为致密的，或为含有纳米级和/或微米级孔径的孔隙。利用具有三维连通网络结构的高分子树脂泡沫材料，采用本发明所述的结构设计和制备方法，制得三维连通网络的中空泡沫材料。该中空泡沫材料同时具有尺寸可调控的三种类型的孔隙：宏观三维连通的开孔网孔、三维连通的中空微通道、微通道管壁本体内的纳米级和/或微米级孔径的孔隙。该中空泡沫材料的具有三维连通中空微通道这一创新性结构特性，为其应用奠定基础。The invention relates to the field of porous materials, in particular to a hollow foam material and a preparation method and application thereof. The hollow foam material is macroscopically constructed from a three-dimensionally connected supporting skeleton network, the supporting skeleton itself is a three-dimensionally connected microchannel with a hollow structure, and the wall of the microchannel is dense, or contains nanoscale and/or microscale. pore size pores. Using the polymer resin foam material with a three-dimensional connected network structure and the structure design and preparation method of the present invention, a three-dimensional connected network hollow foam material is prepared. The hollow foam material simultaneously has three types of pores with adjustable size: macroscopic three-dimensionally connected open-cell mesh, three-dimensionally connected hollow microchannels, and pores with nanoscale and/or microscale pore sizes in the microchannel wall body. The innovative structural feature of the hollow foam material with three-dimensional connected hollow microchannels lays the foundation for its application.

Description

Hollow foam material and preparation method and application thereof

Technical Field

The invention relates to the field of foam materials, in particular to a three-dimensional communicated hollow foam material and a preparation method and application thereof.

Background

The foam material is a special porous material, and the geometrical structural characteristics of the foam material are that polygonal closed rings are used as basic units, and the basic units are connected with each other to form a three-dimensional communication network. The material with the structure has the advantages of light weight, adjustable porosity, high permeability and the like, and the mass transfer efficiency, the momentum transfer efficiency and the heat transfer efficiency of fluid in the three-dimensional communicated meshes can be effectively improved. Therefore, in the field of chemical process intensification, the preparation and application of foam materials are gradually receiving wide attention.

However, the conventional foam obtained by the preparation method described in patent US3090094 based on k.schwartzwalder, although it may contain hollow structures in its supporting skeleton, is restricted by the structure of the formwork in its preparation process, and the shape and size of the cells of the hollow pores in the cross section of the supporting skeleton cannot be controlled. This results in that the three-dimensionally connected open-cell structure of the conventional foam is difficult to realize when the distribution of the fluid is required to be finely controlled or when a plurality of fluids are required to be simultaneously controlled.

The hollow material is a material containing a specific cavity inside, and the research focus is mainly on hollow fiber materials, i.e. chemical fibers with thin tubular cavities in the axial direction of the fiber. The wall of the hollow fiber pipe is distributed with micropores, the pore diameter can be expressed by the molecular weight of the trapped substance, and the trapped molecular weight can reach thousands to hundreds of thousands. Therefore, the module assembled by the hollow fiber is widely researched and applied in the fields of microfiltration, ultrafiltration, dialysis, gas separation, reverse osmosis, evaporation permeators and the like.

Although the hollow fiber has many advantages, in the practical application process of the device assembled by the hollow fiber, the flowing state of the fluid is mainly parallel flow or cross flow, the transfer of the substance is mainly limited by the law of diffusion, and the mass transfer efficiency is not high. On the other hand, the main component of the hollow fibers is chemical fibers at present, and therefore the use temperature is generally not more than 400 ℃. Therefore, there is a need to develop a novel hollow material with high mass transfer efficiency and mechanical properties, high temperature resistance, corrosion resistance and oxidation resistance.

Disclosure of Invention

The invention aims to provide a structural design of a hollow foam material, and a preparation method and application thereof, and solves the problems of low fluid mass transfer efficiency, no high temperature resistance, no oxidation resistance, poor corrosion resistance, poor mechanical property and the like of the material in the prior art.

The invention creatively introduces the hollow structure into the foam material to develop the hollow foam material, so that the hollow foam material has a three-dimensional communication network open-cell structure of the foam material and a thin tubular cavity structure of the hollow material. Meanwhile, a targeted preparation process is provided for the innovative pore structure of the hollow foam material, which is one of the main innovation points of the invention.

The technical scheme of the invention is as follows:

a three-dimensionally interconnected hollow foam material which, macroscopically, is interconnected three-dimensionally by a supporting skeleton (a) to form a network of open cells (b), wherein the supporting skeleton (a) itself has dimensionally controllable, hollow microchannels (c) which have a cross-section which is approximately circular or elliptical.

The pipe wall of the hollow micro-channel (c) is a porous structure pipe wall or a dense structure pipe wall.

The porous structure pipe wall body contains pores with nanometer and/or micron-sized pore diameters.

The material of the pipe wall body can be homogeneous or heterogeneous.

The physical or chemical structure of the tube wall body may be isotropic or anisotropic.

The mesh size (d1) of the openings (b) is 0.2 mm-20 mm.

The hollow micro-channel (c) has an outer diameter (d2) of 0.1mm to 10mm and an inner diameter (d3) of 0.02mm to 9 mm.

The pore size range of pores contained in the porous pipe wall is 0.1 nm-100 mu m, and the porosity p of the pipe wall is more than 0 and less than or equal to 70 percent.

The hollow foam material is made of one or more than two of the following materials: metal, ceramic, polymer, carbon material.

The metal material is selected from one or more of simple metal substances, alloys containing the elements, metal solid solutions or intermetallic compounds containing Li, Na, K, Al, Ca, Sr, Mg, Ni, Fe, Cu, V, Cr, Mo, W, Mn, Co, Zn, Y, Zr, Nb, Ag, Pd, Ru, Rh, Au, Pt, Ta, lanthanide metals and actinide metals;

the ceramic material is selected from one or more than two of the following materials: (1) oxides and composite oxides: al (Al)₂O₃、SiO₂、ZrO₂、MgO、CaO、BeO、SrO、NiO、CuO、TiO₂、V₂O₅、Fe₃O、RuO₂、WO₃、ZnO、SnO₂、CdO、Nb₂O₅、PbO、Pb₃O₄、Bi₂O₃、MoO₃、Cr₂O₃、Y₂O₃、MnO、MnO₂、Mn₂O₃、Mn₃O₄、CoO、Co₃O₄、Co₂O₃Oxides of lanthanides, actinides; mullite (3 Al)₂O₃·2SiO₂) Aluminummagnesium spinel (MgO. multidot.3Al)₂O₃) Magnesium chromium spinel (MgO. Cr)₂O₃) Zircon (ZrO)₂·SiO₂) Calcium metasilicate (2 CaO. SiO)₂) Forsterite (2 MgO. SiO)₂) Perovskite type composite oxide (CaTiO)₃Or doped CaTiO₃、BaTiO₃Or doped BaTiO₃、LiNbO₃Or doped LiNbO₃、SrZrO₃Or doped SrZrO₃、LaMnO₃Or doped LaMnO₃Doped SrCo_yFe-_1-yO_3-δLa substituted at position A with y being more than 0 and less than 1 and delta being more than 0 and less than 3_xA_1- _xCo_yFe_1-yO_3-δWherein A is Sr, Ba, Ca, 0< x < 1, 0< y < 1, 0< delta < 3); (2) carbide: silicon carbide, zirconium carbide, tungsten carbide, titanium carbide, boron carbide, tantalum carbide, vanadium carbide, chromium carbide, niobium carbide, molybdenum carbide, iron carbide, and manganese carbide; (3) nitride: alpha-Si₃N₄、β-Si₃N₄、AlN、Si_6-xAl_xO_xN_8-x、BN；(4)Si；

The polymer material is selected from one or more than two of the following materials: (1) polyolefins: polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyacrylonitrile; (2) polyamides: polycaprolactam (PA6), polyhexamethylene sebacamide (PA610), polyundecanolactam (PA11), polyhexamethylene dodecanoamide (PA612), polyhexamethylene sebacamide (PA 1010); (3) polyesters: polyurethane, polymethyl methacrylate, Polyisocyanurate (PIR), polycarbonate, polybutylene terephthalate (PBT), polyethylene terephthalate (PET); (4) polyethers: polyphenylene oxide, polyphenylene sulfide;

the carbon material is selected from one or more than two of the following materials: graphite, amorphous carbon, graphene, diamond, activated carbon, ordered mesoporous carbon, disordered mesoporous carbon, carbon fiber, carbon nano-tube and carbon micro-tube.

The invention also provides a method for preparing the hollow foam material, which comprises the following steps:

(1) the preparation process of the sacrificial template foam material comprises the following steps: firstly, adopting a high polymer resin foam material with a three-dimensional communication network structure as an initial template material, wherein the high polymer resin foam material is one or more than two of epoxy resin, phenolic resin, furan resin, polyurethane, polyester and polyether; secondly, thickening the network framework ribs of the polymer resin foam material until the thickness degree of the framework ribs reaches the required size of the inner diameter of the hollow micro-channel, namely 0.02-9 mm, so as to prepare the sacrificial template foam material;

(2) preparing a foam material preform: the process is selected from one or a combination of two or more of the following: (a) preparing slurry of a green layer of the pipe wall of the microchannel, fully soaking the foam material of the sacrificial template obtained in the step (1) into the slurry of the green layer, then taking out, removing the redundant slurry, and semi-curing at 80-150 ℃; circularly performing the operations of slurry impregnation, excess slurry removal and semi-solidification until the thickness of the green layer on the pipe wall of the micro-channel reaches a preset design value, and finally completely solidifying the sample at 100-300 ℃ to obtain a foam material prefabricated body; (b) constructing a microchannel pipe wall green body layer on the surface of the framework rib of the foam material of the sacrificial template by adopting an electroplating method, thereby preparing a foam material prefabricated body; (c) constructing a microchannel tube wall green body layer on the surface of a framework rib of the foam material of the sacrificial template by adopting a chemical plating method, thereby preparing a foam material prefabricated body; (d) etching the green layer of the pipe wall of the micro-channel by adopting a solution etching method to construct the green layer of the pipe wall of the micro-channel with a specific geometric structure or specific chemical substance distribution, thereby preparing a foam material prefabricated body; (e) constructing a green body layer of the wall of the micro-channel tube by adopting a specific crystal grown by a hydrothermal reaction method, thereby preparing a foam material prefabricated body; (f) carrying out anodic oxidation treatment on the microchannel tube wall green body layer by adopting an anodic oxidation method to construct a microchannel tube wall green body layer with a specific geometric structure or specific chemical substance distribution, thereby preparing a foam material prefabricated body; (g) constructing a green body layer of the wall of the micro-channel tube by adopting a sol-gel method to prepare a foam material prefabricated body; (h) constructing a thin film layer green body layer with Langmuir-Blodgett film characteristics by adopting a Langmuir-Blodgett method, thereby preparing a foam material prefabricated body; (i) constructing a green body layer of the wall of the micro-channel tube by adopting a physical vapor deposition method, thereby preparing a foam material prefabricated body; (j) constructing a green body layer of the wall of the micro-channel tube by adopting a chemical vapor deposition method, thereby preparing a foam material prefabricated body;

(3) removing the foam material of the sacrificial template: pyrolyzing the foam material preform prepared in the step (2) under the protection of inert gas, wherein the heating rate is 1-10 ℃/min, the pyrolysis temperature is 600-900 ℃, the heat preservation time is 10-300 min, and the obtained sample is treated according to one or more than two of the following operations: cleaning with acid solution, cleaning with alkali solution, cleaning with acetone, cleaning with absolute ethyl alcohol, cleaning with deionized water, and roasting in air; preparing a hollow foam material molding precursor;

(4) a molding procedure: the process is selected from one or a combination of two or more of the following: (a) sintering the foam material forming precursor obtained in the step (3) at high temperature of 900-2500 ℃ in a protective atmosphere for 10 min-6 h; the protective atmosphere is one or more than two of high-purity argon protection, high-purity hydrogen protection, high-purity nitrogen protection, high-purity hydrogen and argon mixed gas protection and vacuum condition; (b) forming operation is carried out by adopting an electroplating method; (c) carrying out forming operation by adopting a chemical plating method; (d) carrying out forming operation by adopting a solution etching method; (e) carrying out forming operation by adopting a hydrothermal reaction method; (f) molding by an anodic oxidation method; (g) carrying out forming operation by adopting a sol-gel method; (h) forming by adopting a Langmuir-Blodgett method; (i) carrying out forming operation by adopting a physical vapor deposition method; (j) carrying out forming operation by adopting a chemical vapor deposition method; (k) applying voltage to the sample to perform electrifying heating to complete the molding operation;

(5) and a post-treatment process: and (3) carrying out one or more than two of the following operations on the molded sample obtained in the step (4): acid solution cleaning, alkali solution cleaning, acetone cleaning, absolute ethyl alcohol cleaning, deionized water cleaning and roasting in air, thereby preparing the three-dimensionally communicated hollow foam material.

The thickening treatment in the step (1) is one or more than two of the following: thickening by an electroplating method, thickening by a chemical plating method and a sol-gel method.

The thickening treatment in the step (1) is carried out according to the following steps: according to the main components: solvent 100 g: (50-200) g, preparing thickening slurry, immersing an initial template material into the thickening slurry, and circularly performing impregnation, removing excess slurry, semi-curing until the thickness of the framework rib reaches the required size of the inner diameter of the hollow micro-channel, namely 0.02-9 mm, wherein the main component of the thickening slurry is one or more than two of the following substances: polyurethane, phenolic resin, epoxy resin, furan resin, polyvinyl alcohol, polyvinyl butyral, isocyanate, modified isocyanate, carboxymethyl cellulose, cellulose acetate, starch, alumina, magnesia, silica, calcium oxide, ferric oxide, ferroferric oxide, cobalt oxide, manganese oxide, copper oxide, zinc oxide, tin oxide, nickel oxide, graphite, amorphous carbon, graphene, diamond, activated carbon, ordered mesoporous carbon, unordered mesoporous carbon, carbon fiber, carbon nanotube, potassium salt, sodium salt, calcium salt, magnesium salt, aluminum salt, ferrous salt, iron salt, copper salt, manganese salt, nickel salt, zinc salt, ammonium salt, tartrate, bisulfite, sulfite, thiosulfate, halide salt, sulfonate salt, salicylate, benzoate, acetate, phosphate, carbonate, bicarbonate, lactate salt, sodium salt, manganese salt, nickel salt, sodium salt, potassium salt, calcium salt, aluminum salt, iron salt, copper salt, manganese salt, lithium salt, sodium salt, tartrate, bisulfite salt, sodium, Sulfates, nitrates, Li, Na, K, Al, Ca, Sr, Mg, Ni, Fe, Cu, V, Cr, Mo, W, Mn, Co, Zn, Y, Zr, Nb, Ag, Pd, Ru, Rh, Au, Pt, Ta, lanthanoids, actinide metals, alloys containing the above elements, metal solid solutions or intermetallic compounds; the solvent is selected from one or more than two of the following: water, ethanol, acetone, ethylene glycol, cyclohexane, n-hexane, toluene, xylene and tetrahydrofuran.

In the step (2), the slurry of the green layer of the tube wall of the microchannel is prepared from main component powder, a binder, a curing agent and a solvent according to the weight ratio of 50-500 g: 50-200 g: (more than 0 to 0.2) times the binder mass: 1000mL of the mixture is prepared by fully ball-milling and mixing;

wherein, the main component powder is selected from one or more than two of metal, ceramic, polymer or carbon material;

the carbon material is selected from one or more than two of the following materials: graphite, amorphous carbon, graphene, diamond, activated carbon, ordered mesoporous carbon, disordered mesoporous carbon, carbon fiber, carbon nanotube and carbon nanotube;

the binder is one or more than two of polyvinyl alcohol, polyvinyl butyral, carboxymethyl cellulose, chitosan, alginic acid, sodium alginate, epoxy resin, phenolic resin, furan resin, polyurethane, polycarbosilane, polyborosilazane, polyborosiloxane, polyborosilazane and polyzirconium borosilazane;

the curing agent is formaldehyde, glutaraldehyde, p-xylylene aldehyde, water-soluble amine-formaldehyde condensate, dimethyl urea, trimethyl melamine, dimethyl ethyl urea, sodium sulfate, zinc sulfate, boric acid, borax, silane crosslinking agent, dichromate, chromium nitrate, chromium complex, cuprammonium hydroxide, urea, melamine, phenol, polyisocyanate, diethyl oxalate, dimethyl oxalate, propylene glycol, organic titanium, epichlorohydrin, chlorohydrin, sodium tetraborate, N-methylolacrylamide, N' -methylenebisacrylamide, beta-cyclodextrin, isopropylacrylamide, acrylamide, acrylic acid, methyl methacrylate, vanillin, genipin, glyoxal, poly (N-ethylene glycol) -acetaldehyde, polyacrylonitrile, succinic acid and its derivatives, glycine, lysine, and/or their derivatives, Diisocyanatohexane, trimellitic anhydride, bromodecane, p-azidobenzoic acid, heparin, ethylene glycol diglycidyl ether, epichlorohydrin, acetic acid, citric acid, formic acid, glycolic acid, lactic acid, malic acid, propionic acid, fatty acid, sodium citrate, calcium chloride, polyethylene glycol, aliphatic diamines, polyamines, aromatic polyamines, dicyandiamide, imidazoles, modified amines, boron trifluoride and complexes, low molecular polyamides, hexamethylenetetramine, benzenesulfonyl chloride, p-toluenesulfonyl chloride, ethyl sulfate, petroleum sulfonic acid, p-toluenesulfonic acid, sodium p-toluenesulfonate, paraformaldehyde, sodium hydroxide, triacetin, propylene carbonate, methylolurea, sulfuric acid, hydrochloric acid, phosphoric acid, oxalic acid, adipic acid, benzenesulfonic acid, phthalic anhydride, maleic anhydride, 3' -dichloro-4, one or more than two of 4' -diaminodiphenylmethane and divinylbenzene;

the solvent is one or more of water, ethanol, acetone, ethylene glycol, toluene and xylene.

And (3) the slurry of the raw layer of the tube wall of the microchannel also contains a pore-forming agent so as to regulate and control the pore structure of the tube wall of the microchannel. The regulation step is preferably as follows: (1) the pore-forming agent is selected from one or more than two of metal pore-forming agent, oxide pore-forming agent, polymer pore-forming agent, inorganic salt pore-forming agent and carbon material pore-forming agent, the particle size of the pore-forming agent is 1 nm-100 mu m, and the addition amount of the pore-forming agent is 0.001-20% of the total mass of the slurry of the green layer on the tube wall of the microchannel; (2) and (3) carrying out 'slurry dipping-excess slurry removal-semi-curing' cyclic operation by sequentially adopting the slurry of the raw material layer of the pipe wall of the microchannel containing the same or different pore-forming agents by stages to form the foam material prefabricated body with the raw material layer of the pipe wall of the microchannel, which is homogeneous or non-homogeneous.

The structure of the green layer of the tube wall of the microchannel in the step (2) can be a partial porous structure, a uniform porous structure or a completely non-porous structure.

And (3) removing the pores through any one or more than two combined operations in the steps (3), (4) and (5), and further preparing the hollow foam material with the micro-channel pipe wall with the compact structure.

And (5) a functional modification process, namely performing functional modification on the outer wall surface and the inner wall surface of the wall of the microchannel or the nano-pores or the micropores contained in the wall of the microchannel by one or more of an electroplating method, a chemical plating method, a solution etching method, an anodic oxidation method, a sol-gel method, a hydrothermal reaction method, a vapor phase conversion method, a Langmuir-Blodgett method, a physical vapor deposition method and a chemical vapor deposition method.

The hollow foam material of the present invention can be applied to any of the following fields: membrane separation material, reaction separation material, filter material, extraction separation material, reaction extraction separation material, catalytic carrier material, microreactor, micro heat exchange material, composite material reinforcement, electrode material, sound absorption/noise reduction material, heat insulation material, fluid distribution material, material for reaction fractionation, material for reaction rectification, fixed valve in the fractionating/rectifying tower and the like.

The invention has the following advantages and beneficial effects:

1. the hollow foam material of the present invention has three types of pores: macroscopic three-dimensional communicated meshes, three-dimensional communicated hollow micro-channels and micro-or/and nano-scale pores in the wall of the micro-channel tube. The hollow foam material comprehensively utilizes the multi-type pores and the multi-level pores, and is favorable for mass transfer, momentum transfer and heat transfer of fluid flowing through the hollow foam material.

2. The cross section of the microchannel (c) is in a near-circular or elliptical shape, so that the microchannel wall with uniform thickness can be prepared, and the structural stability of the microchannel wall is improved.

3. Compared with the common foam material, the introduction of the hollow structure in the invention is beneficial to preparing novel functional materials and composite materials with special structures.

4. The hollow foam material of the three-dimensional communication network has the characteristics of high mass transfer efficiency, high mechanical property, high temperature resistance, corrosion resistance, oxidation resistance and the like.

5. The invention has simple technical process and does not need complex equipment. The hollow foam material is high temperature resistant, oxidation resistant and corrosion resistant, and has good mechanical properties.

6. The hollow foam material is a brand-new porous material, has wide application prospect, and can be applied to the following fields: membrane separation material, reaction separation material, filter material, extraction separation material, reaction extraction separation material, catalytic carrier material, microreactor, micro heat exchange material, composite material reinforcement, electrode material, sound absorption/noise reduction material, heat insulation material, fluid distribution material, material for reaction fractionation, material for reaction rectification, fixed valve in the fractionating/rectifying tower and the like.

Drawings

FIG. 1 is a macroscopic view of a hollow foam material having porous tube walls according to the present invention.

FIG. 2 is a partially enlarged view of a hollow foam having a porous tube wall according to the present invention.

FIG. 3 is a hollow microchannel tube wall topography of the hollow foam with porous tube walls of the present invention.

FIG. 4 is a hollow microchannel wall microstructure of the hollow foam material having a porous wall according to the present invention.

FIG. 5 is a macroscopic view of a hollow foam with dense walls according to the present invention.

FIG. 6 is a close-up view of a hollow foam with dense walls according to the present invention.

FIG. 7 is a hollow microchannel tube wall topography of the hollow foam with dense tube walls of the present invention.

FIG. 8 is a flow chart of a process for preparing the hollow foam of the present invention.

Detailed Description

As shown in fig. 8, in the specific embodiment of the structural design and the preparation process of the hollow foam material, the present invention prepares slurry by using main components and pore-forming agent powder, polymer material, and solvent as basic raw materials, uses a three-dimensional communicated sacrificial template foam material with framework ribs subjected to thickening treatment as a template material, and adopts a preparation process represented by "dipping slurry-removing excess slurry, drying and curing-preprocessing-high-temperature sintering and molding-post treatment (selection)" ("dipping slurry-removing excess slurry-drying and curing" operation is to construct a raw layer of the wall of the microchannel tube of the framework rib, which can be circularly performed until the thickness of the raw layer of the wall of the microchannel tube reaches a design value), and the following embodiments are listed according to the specific process of preparing the hollow foam material:

example 1

The preparation process of the embodiment is a preparation process of a hollow foam silicon carbide material with a porous structure and a microchannel tube wall:

(1) preparing a thickening slurry: fully ball-milling and mixing polyvinyl alcohol powder, epoxy resin, a curing agent and ethanol to prepare a thickening slurry, wherein the ratio of the polyvinyl alcohol to the epoxy resin to the curing agent to the ethanol is 50-500 g: greater than 0 to 500 g: 10-100 g: 1000mL (namely, every 1000mL of solvent in the slurry corresponds to 50-500 g of polyvinyl alcohol powder, more than 0-500 g of epoxy resin and 10-100 g of curing agent corresponding to the epoxy resin).

(2) Preparing slurry of the green layer of the pipe wall of the microchannel: silicon carbide powder (average particle size of 5 μm), silicon powder (average particle size of 3.5 μm), phenolic resin, p-toluenesulfonic acid (curing agent) and ethanol are mixed according to the proportion of 50-500 g: 50-500 g: 50-200 g: (more than 0 to 0.2) times the mass of the phenolic resin: 1000mL, and preparing the slurry of the raw blank layer of the tube wall of the micro-channel by fully ball-milling and mixing.

(3) Preparation of sacrificial template foam: adopting a polyurethane resin foam material with an average mesh size of 3mm and a three-dimensional communicated network structure to thicken network framework ribs of the polyurethane resin foam material: and (2) soaking polyurethane resin foam into the thickening slurry prepared in the step (1), taking out the polyurethane resin foam, removing the redundant slurry in meshes of the foam template material, and semi-curing at 80-150 ℃. According to the requirement of the required size (0.02 mm-9 mm) of the inner diameter of the hollow micro-channel of the hollow foam material to be finally prepared, the operations of 'slurry dipping-slurry removal-semi-solidification' are circularly carried out for a plurality of times until the thickness degree of the network framework rib reaches the pre-designed value of 550 mu m.

(4) Preparing a foam material preform: namely the construction of a tube wall green body layer of the hollow micro-channel of the three-dimensional communication network. And (3) cutting the three-dimensional communicated sacrificial template foam material with the thickness degree of the network framework ribs increased to a preset design value to a required shape and size, fully immersing the three-dimensional communicated sacrificial template foam material into the slurry of the raw material layer of the wall of the microchannel tube prepared in the step (2), removing the redundant slurry in the meshes of the template foam material, and semi-curing at 80-150 ℃. According to the requirement of the wall thickness of the hollow micro-channel pipe designed in advance, the operations of slurry hanging, redundant slurry removing and semi-solidification can be carried out for a plurality of times in a circulating mode, finally the obtained skeleton foam is completely solidified at the temperature of 200-300 ℃, the construction of a green layer of the pipe wall of the micro-channel is completed, and the prefabricated foam material is obtained.

(5) Removing the foam material of the sacrificial template: removing the foam material of the sacrificial template from the prefabricated foam material under the protection of high-purity argon (the volume fraction of the argon is more than or equal to 99.999%) or other inert gases, wherein the heating rate is 1-10 ℃/min, the processing temperature is 600-900 ℃, the heat preservation time is 10-300 min, and the obtained sample can be processed by one or more than two methods selected from the following operations: cleaning with acid solution, cleaning with alkali solution, cleaning with acetone, cleaning with absolute ethyl alcohol, cleaning with deionized water, roasting in air, and completely drying to obtain the hollow foam material molding precursor.

(6) A molding procedure: and (3) sintering the formed precursor at high temperature of 900-2500 ℃ under the protection of high-purity argon or under vacuum condition, and keeping the temperature for 10 min-6 h.

(7) Post-treatment (optional): subjecting the sample obtained in step (6) to one or more of the following operations: cleaning with an acid solution, cleaning with an alkali solution, cleaning with an organic solvent (including but not limited to acetone and absolute ethyl alcohol), cleaning with deionized water, roasting in air, and calcining under the protection of an inert atmosphere to obtain the hollow foam material with the three-dimensional communication network. The hollow foam material mainly comprises silicon carbide, the structure of the hollow foam material is macroscopically constructed by a three-dimensionally communicated supporting skeleton network, and the average value of the mesh sizes of macroscopically three-dimensionally communicated open pores is 2.5 mm. The network skeleton is a three-dimensionally communicated microchannel with a hollow structure, the average size of the inner diameter of the hollow microchannel is 500 μm, and the average size of the outer diameter of the hollow microchannel is 900 μm. The chemical composition of the wall of the microchannel mainly comprises silicon carbide, the wall of the microchannel contains pores with the pore diameters from nano-scale to micron-scale, the average pore diameter is 5 mu m, and the porosity is 50 percent.

Example 2

The preparation process of the embodiment is a preparation process of a hollow foam silicon carbide material with a dense-structure microchannel tube wall: the difference between this embodiment and embodiment 1 is that the molding process in step (6) is: and (3) placing the formed precursor in a vacuum sintering furnace, and uniformly placing silicon powder particles with the average particle size of 3mm on a formed precursor sample. And (3) under the condition of vacuumizing, keeping the temperature at 900-2500 ℃ for 10 min-6 h. The average mesh size of the macroscopically three-dimensionally connected open cells of the hollow foam obtained was 0.5 mm. The support skeleton is a three-dimensionally connected microchannel with a hollow structure, the average size of the inner diameter of the hollow microchannel is 250 μm, and the average size of the outer diameter of the hollow microchannel is 550 μm. The wall of the micro-channel tube is of a compact structure, and the chemical composition of the micro-channel tube mainly comprises silicon carbide and silicon.

Example 3

The preparation process of the embodiment is a preparation process of a hollow foamed aluminum oxide material with a microchannel tube wall with a porous structure: this example is different from example 1 in that the epoxy resin in step (1) is replaced with polyurethane. In the step (2), the slurry of the green layer on the wall of the microchannel tube comprises the following components: alumina powder (average particle size is 5 μm), phenolic resin, p-toluenesulfonic acid (curing agent) and ethanol according to the proportion of 50-500 g: 50-200 g: (more than 0 to 0.2) times the mass of the phenolic resin: 1000 mL. The polyurethane resin foam having an average cell diameter of 3mm in step (3) was replaced with a polyurethane resin foam having an average cell size of 5 mm. And (4) the thickness degree of the framework ribs of the supporting framework in the step (3) reaches the pre-designed value of 600 mu m. The average mesh size of the macroscopically three-dimensionally connected open cells of the hollow foam obtained was 4 mm. The support skeleton is a three-dimensionally communicated microchannel with a hollow structure, the average size of the inner diameter of the hollow microchannel is 550 μm, and the average size of the outer diameter of the hollow microchannel is 1000 μm. The chemical composition of the microchannel wall mainly comprises alumina, the microchannel wall contains pores with the pore diameters from nanometer to micron, the average pore diameter is 4 mu m, and the porosity is 70%.

Example 4

The preparation process of the embodiment is a preparation process of a hollow foamed aluminum oxide material with a micro-channel pipe wall with a compact structure, and comprises the following steps: this example is different from example 1 in that the epoxy resin in step (1) is replaced with polyurethane. In the step (2), the slurry of the green layer on the wall of the microchannel tube comprises the following components: alumina powder (average particle diameter 5 μm), alumina sol (a (Al)₂O₃·nH₂O)·bHx·cH₂O) and water in a proportion of 50-500 g: 50-500 g: 1000 mL. The polyurethane resin foam having an average cell diameter of 3mm in step (3) was replaced with a polyurethane resin foam having an average cell size of 5 mm. And (4) the thickness degree of the framework ribs of the supporting framework in the step (3) reaches the preset design value of 1100 mu m. The average mesh size of the macroscopically three-dimensionally connected open cells of the hollow foam obtained was 4 mm. The support framework is a three-dimensionally communicated microchannel with a hollow structure, the average size of the inner diameter of the hollow microchannel is 1000 μm, and the average size of the outer diameter of the hollow microchannel is 1600 μm. The microchannel walls are dense structures whose chemical composition comprises primarily alumina.

Example 5

The preparation process of the embodiment is a preparation process of a hollow foam sialon material of a microchannel tube wall with a porous structure: this example is different from example 1 in that the epoxy resin in step (1) was replaced with polyurethane, and the polyurethane resin foam having an average cell diameter of 3mm in step (3) was replaced with a polyurethane resin foam having an average cell size of 8 mm. In the step (2), the slurry comprises the following components: silicon carbide powder (average particle size 5 μm), silicon powder (average particle size 3.5 μm), silicon oxide powder (average particle size 1 μm), activated alumina powder(average particle size is 2 μm), phenolic resin, p-toluenesulfonic acid (curing agent), and ethanol are mixed according to the proportion of 50-500 g: 50-500 g: 50-500 g: 50-500 g: 50-200 g: (more than 0 to 0.2) times the mass of the phenolic resin: 1000 mL. And (4) the thickness degree of the framework ribs of the supporting framework in the step (3) reaches a predesigned value of 2200 mu m. And (6) sintering the pretreated molded precursor at high temperature in a high-purity nitrogen atmosphere at 1200-2500 ℃ for 10 min-6 h. The average mesh size of the macroscopically three-dimensionally connected open cells of the hollow foam obtained was 5 mm. The support framework is a three-dimensionally communicated microchannel with a hollow structure, the average size of the inner diameter of the hollow microchannel is 2000 μm, and the average size of the outer diameter of the hollow microchannel is 3000 μm. The chemical composition of the microchannel walls consists essentially of sialon (Si)_6-xAl_xO_xN_8-x) And the wall of the micro-channel tube contains pores with the pore diameters from nano-scale to micro-scale, the average pore diameter is 3 mu m, and the porosity is 30 percent.

Example 6

The preparation process of the embodiment is a preparation process of a hollow foam silicon carbide material with a microchannel tube wall with an asymmetric porous structure: this example is different from example 1 in that the epoxy resin in step (1) was replaced with polyurethane, and the polyurethane resin foam having an average cell diameter of 3mm in step (3) was replaced with a polyurethane resin foam having an average cell size of 5 mm. In the step (2), two kinds of slurry are prepared, wherein the slurry A comprises the following components: silicon carbide powder (average particle size is 5 μm), silicon powder (average particle size is 3.5 μm), phenolic resin, p-toluenesulfonic acid (curing agent) and ethanol are mixed according to the proportion of 50-500 g: 50-500 g: 50-200 g: (more than 0 to 0.2) times the mass of the phenolic resin: 1000 mL. The composition of slurry B was: silicon carbide powder (average particle size of 0.5 μm), silicon powder (average particle size of 0.5 μm), phenolic resin, p-toluenesulfonic acid (curing agent) and ethanol are mixed according to the proportion of 50-500 g: 50-500 g: 50-200 g: (more than 0 to 0.2) times the mass of the phenolic resin: 1000 mL. And (4) the thickness degree of the framework ribs of the supporting framework in the step (3) reaches the pre-designed value of 600 mu m. In the construction process of the raw material layer of the pipe wall of the microchannel in the step (4), the slurry A in the step (2) is utilized to carry out operation circulation of slurry coating, excess slurry removal and semi-solidification for a plurality of times; and (3) circularly performing operation of 'hanging the slurry', removing the redundant slurry 'and semi-curing' on the slurry B in the step (2) for a plurality of times. The average mesh size of the macroscopically three-dimensionally connected open cells of the hollow foam obtained was 4 mm. The support skeleton is a three-dimensionally communicated microchannel with a hollow structure, the average size of the inner diameter of the hollow microchannel is 550 μm, and the average size of the outer diameter of the hollow microchannel is 1000 μm. The chemical composition of the wall of the microchannel mainly comprises silicon carbide, and the wall of the microchannel contains asymmetric pores with the pore diameters from nanometer to micron (namely, the pore structure of the wall layer of the microchannel tube is anisotropic), wherein the average pore diameter of a 200-micron-thickness area close to the inner wall side of the wall of the tube wall is 4 microns, and the porosity is 50%. The average pore diameter in the 25 μm thick region near the outer wall side of the tube wall was 1 μm, and the porosity was 45%.

Example 7

The preparation process of this example is a preparation process of a hollow foamed stainless steel material having a microchannel tube wall with a porous structure, and the difference between this example and example 1 is that polyurethane is used in place of the epoxy resin in step (1), and polyurethane resin foam material with an average mesh size of 5mm is used in place of the polyurethane resin foam with an average pore size of 3mm in step (3). In the step (2), the slurry comprises the following components: 316L stainless steel powder (with the particle size ranging from 10 to 30 mu m), phenolic resin, polyvinyl butyral, a curing agent and ethanol are mixed according to the proportion of 50 to 500 g: 50-200 g: 50-200 g: (more than 0 to 0.2) times the mass of the phenolic resin: 1000 mL. The thickness degree of the supporting skeleton muscle in the step (3) reaches the pre-designed value of 600 mu m. The average mesh size of the macroscopically three-dimensionally connected open cells of the hollow foam obtained was 4 mm. The support skeleton is a three-dimensionally communicated microchannel with a hollow structure, the average size of the inner diameter of the hollow microchannel is 550 μm, and the average size of the outer diameter of the hollow microchannel is 1000 μm. The chemical composition of the wall of the microchannel mainly comprises 316L stainless steel, the wall of the microchannel contains pores with the pore diameters from nanometer to micron, the average pore diameter is 5 mu m, and the porosity is 50 percent.

Example 8

The preparation process of the embodiment is a preparation process of a hollow copper foam material of a microchannel tube wall with a porous structure, and comprises the following steps: this example is different from example 1 in that the epoxy resin in step (1) was replaced with polyurethane, and the polyurethane resin foam having an average cell diameter of 3mm in step (3) was replaced with a polyurethane resin foam having an average cell size of 6 mm. In the step (2), the slurry comprises the following components: copper oxide powder (with the particle size ranging from 10 to 30 mu m), copper powder (with the particle size ranging from 10 to 30 mu m), phenolic resin, polyvinyl butyral, a curing agent and ethanol are mixed according to the proportion of 50 to 500 g: 50-500 g: 50-200 g: 50-200 g: (more than 0 to 0.2) times the mass of the phenolic resin: 1000 mL. The thickness degree of the supporting skeleton muscle in the step (3) reaches the pre-designed value of 600 mu m. The average mesh size of the macroscopically three-dimensionally connected open cells of the hollow foam obtained was 5 mm. The support skeleton is a three-dimensionally communicated microchannel with a hollow structure, the average size of the inner diameter of the hollow microchannel is 550 μm, and the average size of the outer diameter of the hollow microchannel is 1000 μm. The chemical composition of the microchannel wall mainly comprises copper, the microchannel wall contains pores with the pore diameters from nanometer to micron, the average pore diameter is 3 mu m, and the porosity is 40%.

Example 9

The preparation process of the embodiment is a preparation process of a hollow foam copper material with a micro-channel pipe wall with a compact structure, and specifically comprises the following main steps:

(2) Preparing plating solution for the green layer of the tube wall of the microchannel: 10-100 g/L of main salt (copper sulfate, copper chloride, basic copper carbonate, copper tartrate and copper acetate); 10-100 g/L complexing agent (potassium sodium tartrate, sodium citrate, sodium gluconate, triethanolamine, tetrahydroxypropyl ethylenediamine, glycerol, glycolic acid or EDTA disodium salt); 10-100 g/L of reducing agent (formaldehyde, hydrazine, borohydride, dimethylamino borane and sodium hypophosphite); 10-50 g/L of additive (stabilizer, accelerator, leveling agent or brightener); and preparing chemical copper plating aqueous solution by using 10-50 g/L of pH regulator (sodium hydroxide and sodium carbonate).

(4) Preparing a foam material preform: namely the construction of a tube wall green body layer of the hollow micro-channel of the three-dimensional communication network. Cutting the three-dimensional communicated sacrificial template foam material with the thickness degree of the network framework ribs increased to a preset design value into a sample with a required shape and size, fully soaking the sample into 30-50 g/L stannous chloride solution for treatment for 3-5 min, and then placing the sample into 0.5-1 g/L palladium chloride solution for treatment for 1-2 min. And (3) taking out, removing redundant solution in the three-dimensional communicated open hole, putting the solution into the plating solution for the green layer of the tube wall of the micro-channel prepared in the step (2), and performing chemical copper plating operation at the temperature of 20-100 ℃ while maintaining the pH value of 11-13. Determining the electroless copper plating operation time for 1-10 h according to the requirement of the wall thickness of the pre-designed hollow microchannel tube, finally taking out the sample, cleaning and drying to complete the construction of the green layer of the microchannel tube wall, and obtaining the prefabricated foam material.

(5) Removing the foam material of the sacrificial template: removing the foam material of the sacrificial template from the prefabricated foam material under the protection of high-purity argon (the volume fraction of the argon is more than or equal to 99.999%) or other inert gases, wherein the heating rate is 1-10 ℃/min, the processing temperature is 650 ℃, the heat preservation time is 10-300 min, and the obtained sample can be processed by one or more than two methods selected from the following operations: cleaning with acid solution, cleaning with alkali solution, cleaning with acetone, cleaning with absolute ethyl alcohol, cleaning with deionized water, roasting in air, and completely drying to obtain the hollow foam material molding precursor.

(6) A molding procedure: and (3) sintering the formed precursor at high temperature under the protection of high-purity argon or under vacuum condition, wherein the temperature is 800-1050 ℃, the heating rate is 0.5-2 ℃/min, and the heat preservation time is 10 min-6 h.

(7) Post-treatment (optional): subjecting the sample obtained in step (6) to one or more of the following operations: cleaning with an acid solution, cleaning with an alkali solution, cleaning with an organic solvent (including but not limited to acetone and absolute ethyl alcohol), cleaning with deionized water, roasting in air, and calcining under the protection of an inert atmosphere to obtain the hollow foam material with the three-dimensional communication network. The obtained hollow foam material has a structure which is macroscopically constructed by a three-dimensionally communicated supporting skeleton network, and the average value of the mesh sizes of macroscopically three-dimensionally communicated open pores is 2.5 mm. The support skeleton is a three-dimensionally communicated microchannel with a hollow structure, the average size of the inner diameter of the hollow microchannel is 500 μm, and the average size of the outer diameter of the hollow microchannel is 900 μm. The microchannel walls are dense structures whose chemical composition comprises primarily copper.

Example 10

The preparation process of the embodiment is a preparation process of a hollow foam material of a microchannel tube wall with a porous tube wall structure, and specifically comprises the following main steps:

(1) preparing a thickening slurry: fully ball-milling and mixing active magnesium oxide powder, polyurethane, a curing agent and ethanol to prepare a thickening slurry, wherein the proportion of the active magnesium oxide powder, the polyurethane, the curing agent and the ethanol is 50-500 g: greater than 0 to 500 g: 10-100 g: 1000mL (namely, every 1000mL of ethanol in the slurry corresponds to 50-500 g of active magnesium oxide powder, more than 0-500 g of polyurethane and 10-100 g of curing agent corresponding to epoxy resin).

(2) Preparing slurry of the green layer of the pipe wall of the microchannel: mixing polytetrafluoroethylene powder (with an average particle size of 10 mu m), polytetrafluoroethylene emulsion (with a solid content of 60 wt%) and waterborne polyurethane according to a ratio of 50-500 g: 1000 g: 50-500 g, and fully ball-milling and mixing to prepare the slurry of the green layer of the tube wall of the microchannel.

(3) Preparation of sacrificial template foam: adopting a polyurethane resin foam material with an average mesh size of 5mm and a three-dimensional communicated network structure to thicken network framework ribs of the polyurethane resin foam material: and (2) soaking polyurethane resin foam into the thickening slurry prepared in the step (1), taking out the polyurethane resin foam, removing the redundant slurry in meshes of the foam template material, and semi-curing at 80-150 ℃. According to the requirement of the required size (0.02 mm-9 mm) of the inner diameter of the hollow micro-channel of the hollow foam material to be finally prepared, the operations of 'slurry dipping-slurry removal-semi-solidification' are circularly carried out for a plurality of times until the thickness degree of the network framework rib reaches the pre-designed value of 450 mu m.

(4) Preparing a foam material preform: namely the construction of a tube wall green body layer of the hollow micro-channel of the three-dimensional communication network. And (3) cutting the three-dimensional communicated sacrificial template foam material with the thickness degree of the network framework ribs increased to a preset design value to a required shape and size, fully immersing the three-dimensional communicated sacrificial template foam material into the slurry of the raw material layer of the wall of the microchannel tube prepared in the step (2), removing the redundant slurry in the meshes of the template foam material, and semi-curing at 80-100 ℃. According to the requirement of the wall thickness of the hollow micro-channel pipe designed in advance, the operations of slurry hanging, redundant slurry removing and semi-solidification can be carried out for a plurality of times in a circulating mode, finally the obtained skeleton foam is completely solidified at 100-120 ℃, the construction of a green layer of the pipe wall of the micro-channel is completed, and the prefabricated foam material is obtained.

(5) Removing the foam material of the sacrificial template: and cleaning the prefabricated foam material in an acid solution, then cleaning with deionized water, and completely drying to obtain the hollow foam material molding precursor.

(6) A molding procedure: and (3) carrying out molding operation on the molded precursor under the protection of high-purity argon at the temperature of 120-300 ℃ for 10 min-6 h.

(7) Post-treatment (optional): subjecting the sample obtained in step (6) to one or more of the following operations: cleaning with an acid solution, cleaning with an alkali solution, cleaning with an organic solvent (including but not limited to acetone and absolute ethyl alcohol), cleaning with deionized water, roasting in air, and calcining under the protection of an inert atmosphere to obtain the hollow foam material with the three-dimensional communication network. The obtained hollow foam material has a structure which is macroscopically constructed by a three-dimensionally communicated supporting skeleton network, and the average value of the mesh sizes of macroscopically three-dimensionally communicated open pores is 4 mm. The support skeleton is a three-dimensionally communicated microchannel with a hollow structure, the average size of the inner diameter of the hollow microchannel is 400 μm, and the average size of the outer diameter of the hollow microchannel is 900 μm. The chemical composition of the wall of the micro-channel mainly comprises polytetrafluoroethylene, the wall of the micro-channel is of a porous wall structure and contains pores with the pore diameters from nano-scale to micro-scale, the average pore diameter is 5 mu m, and the porosity is 50%.

Example 11

The preparation process of the embodiment is a preparation process of a hollow foamed polyethylene material with a porous structure and a microchannel tube wall, and specifically comprises the following main steps: the difference between this example and example 10 is that the slurry for the green layer of the microchannel tube wall in step (2) is prepared by: mixing polyethylene powder (with an average particle size of 10 mu m), polyethylene emulsion (with a solid content of 40%) and waterborne polyurethane according to a proportion of 50-500 g: 1000 g: 50-500 g, and fully ball-milling and mixing to prepare the slurry of the green layer of the tube wall of the microchannel. The polyurethane resin foam having an average cell diameter of 5mm in step (3) was replaced with a polyurethane resin foam having an average cell size of 8 mm. And (4) the thickness degree of the framework ribs of the supporting framework in the step (3) reaches the pre-designed value of 600 mu m. The semi-curing temperature in the step (4) is 50 ℃, and the final curing temperature is 60 ℃. In the step (6), the molding temperature is 70-220 ℃, and the heat preservation time is 5 min-3 h. The average mesh size of the macroscopically three-dimensionally connected open cells of the hollow foam obtained was 6.5 mm. The support skeleton is a three-dimensionally communicated microchannel with a hollow structure, the average size of the inner diameter of the hollow microchannel is 550 μm, and the average size of the outer diameter of the hollow microchannel is 1000 μm. The wall of the microchannel is a dense structure whose chemical composition mainly comprises polyethylene.

Example 12

The preparation process of the embodiment is a preparation process of a hollow foamy carbon material with a porous structure of a microchannel tube wall: this example is different from example 1 in that the epoxy resin in step (1) is replaced with polyurethane. In the step (2), the slurry of the green layer on the wall of the microchannel tube comprises the following components: activated carbon powder (with an average particle size of 5 microns), phenolic resin, p-toluenesulfonic acid (curing agent) and ethanol are mixed according to a ratio of 50-500 g: 50-200 g: (more than 0 to 0.2) times the mass of the phenolic resin: 1000mL, and preparing the slurry of the raw blank layer of the tube wall of the micro-channel by fully ball-milling and mixing. The polyurethane resin foam having an average cell diameter of 3mm in step (3) was replaced with a polyurethane resin foam having an average cell size of 5 mm. And (4) the thickness degree of the framework ribs of the supporting framework in the step (3) reaches the preset design value of 1100 mu m. The average mesh size of the macroscopically three-dimensionally connected open cells of the hollow foam obtained was 4 mm. The support framework is a three-dimensionally communicated microchannel with a hollow structure, the average size of the inner diameter of the hollow microchannel is 1000 μm, and the average size of the outer diameter of the hollow microchannel is 1600 μm. The chemical composition of the wall of the microchannel mainly comprises activated carbon and amorphous carbon, the wall of the microchannel is of a porous wall structure and contains pores with sub-nanometer to micron pore sizes, the average pore size is 1 mu m, and the porosity is 60%.

Example 13

The preparation process of the embodiment is a preparation process of a hollow foam graphite material with a dense-structure microchannel tube wall: this example is different from example 1 in that the epoxy resin in step (1) is replaced with polyurethane. In the step (2), the slurry of the green layer on the wall of the microchannel tube comprises the following components: activated carbon powder (with an average particle size of 5 microns), phenolic resin, p-toluenesulfonic acid (curing agent) and ethanol are mixed according to a ratio of 50-500 g: 50-200 g: (more than 0 to 0.2) times the mass of the phenolic resin: 1000mL, and preparing the slurry of the raw blank layer of the tube wall of the micro-channel by fully ball-milling and mixing. The polyurethane resin foam having an average cell diameter of 3mm in step (3) was replaced with a polyurethane resin foam having an average cell size of 5 mm. And (4) the thickness degree of the framework ribs of the supporting framework in the step (3) reaches the pre-designed value of 800 microns. The post-treatment process in the step (7) comprises the following steps: and (4) carrying out high-temperature graphitization treatment on the sample prepared in the step (6) in an inert atmosphere at the temperature of 600-3000 ℃. The average mesh size of the macroscopically three-dimensionally connected open cells of the hollow foam obtained was 4 mm. The support skeleton is a three-dimensionally communicated microchannel with a hollow structure, the average size of the inner diameter of the hollow microchannel is 600 μm, and the average size of the outer diameter of the hollow microchannel is 1200 μm. The wall of the micro-channel is a compact wall structure, and the chemical composition of the micro-channel mainly comprises graphite.

Example 14

The preparation process of the embodiment is a preparation process of a hollow foamed aluminum/silicon carbide composite material with a micro-channel tube wall with a compact structure, and comprises the following steps: this example is different from example 1 in that the epoxy resin in step (1) is replaced with polyurethane. The polyurethane resin foam having an average cell diameter of 3mm in step (3) was replaced with a polyurethane resin foam having an average cell size of 5 mm. And (4) the thickness degree of the framework ribs of the supporting framework in the step (3) reaches the pre-designed value of 1000 microns. And (4) in the post-treatment procedure of the step (7), carrying out local high-temperature liquid-phase aluminizing operation on the hollow foam silicon carbide material with the porous structure prepared in the step (6) aiming at the pipe wall area of the microchannel, wherein the aluminizing temperature is 600-1000 ℃, and the time is 1 min-3 h. The average mesh size of the macroscopically three-dimensionally connected open cells of the hollow foam obtained was 4 mm. The support framework is a three-dimensionally communicated microchannel with a hollow structure, the average size of the inner diameter of the hollow microchannel is 800 μm, and the average size of the outer diameter of the hollow microchannel is 1600 μm. The wall of the micro-channel tube is a compact structure, and the chemical composition of the micro-channel tube mainly comprises silicon carbide and aluminum.

As shown in fig. 1, the hollow foam material has a typical foam cellular structure with three-dimensionally connected macroscopic open-cell network pores, as can be seen from the macroscopic morphology of the hollow foam material with porous tube walls.

As shown in fig. 2, as can be seen from the enlarged partial morphology of the hollow foam material with porous pipe walls, the supporting frameworks (a) are three-dimensionally communicated to form an open-cell (b) network structure. Wherein the supporting framework (a) is provided with a size-controllable hollow micro-channel (c), and the cross section of the micro-channel (c) is approximately circular or elliptical.

As shown in fig. 3, the microchannel wall has a porous structure as seen from the morphology of the wall of the hollow microchannel of the hollow foam material having a porous wall.

As shown in fig. 4, from the microscopic morphology of the wall of the hollow microchannel of the hollow foam material with the porous wall, the wall body of the hollow microchannel is composed of micron-sized particles, and the particles have a pore structure.

As shown in fig. 5, it can be seen from the macro-morphology of the hollow foam material with dense tube walls that the hollow foam material has a typical foam cellular structure with three-dimensionally connected macro-open-cell network pores.

As shown in fig. 6, the supporting framework itself is a hollow microchannel, as can be seen from the enlarged partial topography of the hollow foam material with dense tube walls.

As shown in fig. 7, it can be seen from the hollow microchannel tube wall morphology of the hollow foam material with dense tube wall that the hollow microchannel tube wall itself is a dense structure.

The specific implementation mode shows that the macrostructure of the hollow foam material of the three-dimensional communication network is a three-dimensional communication supporting framework, the supporting framework is a three-dimensional communication microchannel with a hollow structure, and pores with nanometer or/and micron-sized apertures are contained in the wall of the microchannel. The method adopts a high polymer resin foam material with a three-dimensional connected network structure as an initial template material, and performs thickening treatment to prepare the sacrificial template foam material with the thickness of the framework rib reaching a set value. The template material cut by the sacrificial template foam material is immersed into slurry of a microchannel tube wall green body layer, wherein the slurry is prepared by fully and uniformly mixing main component powder, high polymer resin and a solvent through ball milling, the slurry is taken out, redundant slurry in meshes in the template is removed, and the operation of 'dipping-slurry removal-drying' is circulated for a plurality of times. And then carrying out pyrolysis pretreatment under a protective atmosphere after high-temperature curing to obtain a foam structure forming precursor of a three-dimensional connected network similar to the original foam shape. And carrying out a molding process and a post-treatment process to obtain the hollow foam material. The technology has simple process and does not need complex equipment. The prepared hollow foam material is a novel foam porous material, and has the innovation points that the hollow foam material simultaneously has three types of pores: a macroscopic three-dimensional communicated open pore network, a three-dimensional communicated hollow micro-channel, and a nano-scale or/and micro-scale pore in the wall of the micro-channel. The hollow foam material is high temperature resistant, oxidation resistant, corrosion resistant and has good mechanical properties.

Claims

1. A method for preparing a three-dimensionally connected hollow foam material, wherein the hollow foam material is macroscopically connected by a supporting framework (a) three-dimensionally to form an open cell (b) network structure, wherein the supporting framework (a) It has a size-controllable, hollow microchannel (c), and the cross-section of the microchannel (c) is nearly circular or elliptical;

The tube wall of the hollow microchannel (c) is a porous structure tube wall or a dense structure tube wall;

The porous structure tube wall body contains nano-scale pores; or, the porous structure tube wall body contains pores with nano-scale and micro-scale pore sizes;

The mesh size d1 of the opening (b) is 0.2 mm to 20 mm;

The outer diameter dimension d2 of the hollow microchannel (c) is 0.1mm～10mm, and the inner diameter dimension d3 is 0.02mm～9mm;

The pore size of the pores contained in the porous tube wall ranges from 0.1 nm to 100 μm, and the porosity p of the tube wall is 0<p≤70%;

The preparation method of the hollow foam material comprises the following steps:

(1) Preparation process of sacrificial template foam material: first, a polymer resin foam material with a three-dimensional connected network structure is used as the initial template material, and the polymer resin foam material is epoxy resin, phenolic resin, furan resin, polyurethane, One or more of polyester and polyether; secondly, the network skeleton rib of the polymer resin foam material is thickened until the thickness of the skeleton rib reaches the required size of the inner diameter of the hollow microchannel of 0.02mm~ 9mm, thereby making sacrificial template foam;

(2) Preparation process of foam material preform: this process is selected from the following one or a combination of two or more: (a) preparing a slurry for the green layer of the microchannel tube wall, and preparing the sacrificial template foam material obtained in step (1) Fully immerse into the green layer slurry, then take it out, remove excess slurry, and perform semi-curing at 80-150°C; the above-mentioned "dipping slurry-removing excess slurry-semi-curing" operation is repeated until the microchannel tube The thickness of the wall green layer reaches the pre-designed value, and finally the sample is completely cured at 100-300 °C to obtain a foam material preform; (b) The micro-channel tube wall is constructed on the surface of the skeleton rib of the sacrificial template foam material by electroplating method. green body layer, thereby preparing a foam material preform; (c) using an electroless plating method to construct a microchannel tube wall green body layer on the surface of the skeleton rib of the sacrificial template foam material, thereby preparing a foam material preform; (d) ) Using a solution etching method, the microchannel tube wall green layer is etched to construct a microchannel tube wall green layer with a specific geometric structure or a specific chemical substance distribution, thereby preparing a foam material preform; (e ) Using the specific crystals grown by the hydrothermal reaction method to construct the green layer of the micro-channel tube wall, thereby preparing the foam material preform; (f) adopting the anodic oxidation method to anodize the green layer of the micro-channel tube wall , constructing a microchannel wall green layer with a specific geometric structure or a specific chemical substance distribution, thereby preparing a foam material preform; (g) using the sol-gel method to construct a microchannel wall green layer, thereby (h) using the Langmuir-Blodgett method to construct a thin-film green body layer with Langmuir-Blodgett film characteristics, thereby preparing a foam preform; (i) using the physical vapor deposition method to construct micro-layers; channel tube wall green layer, thereby preparing a foam material preform; (j) using chemical vapor deposition method to construct a microchannel tube wall green layer, thereby preparing a foam material preform;

(3) The removal process of the sacrificial template foam material: the foam material preform obtained in the step (2) is pyrolyzed under the protection of an inert gas, the heating rate is 1-10°C/min, and the pyrolysis temperature is 600-900°C, The holding time is 10-300min, and the obtained sample is processed according to one or more of the following operations: acid solution cleaning, alkali solution cleaning, acetone cleaning, absolute ethanol cleaning, deionized water cleaning, and roasting in air; Hollow foam material molding precursor;

(4) Forming process: this process is selected from the following one or a combination of two or more: (a) The foam material forming precursor obtained in step (3) is sintered at high temperature under a protective atmosphere at a temperature of 900-2500 ° C, The holding time is 10min to 6h; the protective atmosphere is selected from one or more of high-purity argon protection, high-purity hydrogen protection, high-purity nitrogen protection, high-purity hydrogen-argon mixed gas protection, and vacuum conditions; (b) electroplating is adopted (c) forming operation using electroless plating method; (d) forming operation using solution etching method; (e) forming operation using hydrothermal reaction method; (f) forming operation using anodizing method (g) using the sol-gel method to carry out the forming operation; (h) using the Langmuir-Blodgett method to carry out the forming operation; (i) using the physical vapor deposition method to carry out the forming operation; (j) using the chemical vapor deposition method to carry out the forming operation; (k) Completing the forming operation by applying a voltage to the sample for electrical heating;

(5) Post-treatment process: perform one or more of the following operations on the molded sample obtained in step (4): acid solution cleaning, alkaline solution cleaning, acetone cleaning, absolute ethanol cleaning, deionized water cleaning , calcined in air, thereby obtaining three-dimensional connected hollow foam materials.

2 . The method for preparing a hollow foam material according to claim 1 , wherein the material of the pipe wall body can be homogeneous or heterogeneous. 3 .

3 . The method for preparing a hollow foam material according to claim 1 , wherein the physical structure or chemical structure of the pipe wall body can be isotropic or anisotropic. 4 .

4 . The method for preparing a hollow foam material according to claim 1 , wherein the material of the hollow foam material is selected from one or more of the following: metal, ceramic, polymer, and carbon material. 5 .

5. The preparation method of the hollow foam material according to claim 4, wherein the metal material is selected from the group consisting of Li, Na, K, Al, Ca, Sr, Mg, Ni, Fe, Cu, V, Cr , Mo, W, Mn, Co, Zn, Y, Zr, Nb, Ag, Pd, Ru, Rh, Au, Pt, Ta, lanthanide, actinide metal element, alloy containing the above elements, metal solid solution Or one or more of intermetallic compounds;

The ceramic material is selected from one or more of the following: (1) oxides and composite oxides: Al ₂ O ₃ , SiO ₂ , ZrO ₂ , MgO, CaO, BeO, SrO, NiO, CuO, TiO ₂ , V ₂ O ₅ , Fe ₃ O, RuO ₂ , WO ₃ , ZnO, SnO ₂ , CdO, Nb ₂ O ₅ , PbO, Pb ₃ O ₄ , Bi ₂ O ₃ , MoO ₃ , Cr ₂ O ₃ , Y ₂ O ₃ , MnO, MnO ₂ , Mn ₂ O ₃ , Mn ₃ O ₄ , CoO, Co ₃ O ₄ , Co ₂ O ₃ , lanthanide oxides, actinide oxides, mullite 3Al ₂ O ₃ ·2SiO ₂ , Aluminium Magnesium Spinel MgO·3Al ₂ O ₃ , Magnesium Chromium Spinel MgO·Cr ₂ O ₃ , Zircon ZrO ₂ ·SiO ₂ , Calcium Orthosilicate 2CaO·SiO ₂ , Forsterite 2MgO·SiO ₂ , perovskite-type composite oxide, the perovskite-type composite oxide is CaTiO ₃ or doped CaTiO ₃ , BaTiO ₃ or doped BaTiO ₃ , LiNbO ₃ or doped LiNbO ₃ , SrZrO ₃ or doped SrZrO ₃ , LaMnO ₃ or doped LaMnO ₃ , doped SrCo _y Fe _1-y _O _3-δ , 0< _y <1, 0<δ<3, A-site substituted _LaxA1 - _xCoy Fe _1-y O _3-δ , where A=Sr, Ba, Ca, 0<x<1, 0<y<1, 0<δ<3; (2) Carbides: silicon carbide, zirconium carbide, tungsten carbide , titanium carbide, boron carbide, tantalum carbide, vanadium carbide, chromium carbide, niobium carbide, molybdenum carbide, iron carbide, manganese carbide; (3) Nitride: α-Si ₃ N ₄ , β-Si ₃ N ₄ , AlN, Si _6-x Al _x O _x N _8-x , BN; (4) Si;

The polymer material is selected from one or more of the following: (1) Polyolefins: polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polypropylene, polyvinyl chloride, polystyrene, Polyacrylonitrile; (2) Polyamides: polycaprolactam PA6, polyhexamethylene sebacate PA610, polyundecalactam PA11, polyhexamethylene dodecanediamide PA612, polyhexamethylene sebacate PA1010 ; (3) Polyesters: polyurethane, polymethyl methacrylate, polyisocyanurate, polycarbonate, polydibutyl terephthalate, polyethylene terephthalate; (4) ) Polyethers: polyphenylene ether, polyphenylene sulfide;

The carbon material is selected from one or more of the following: graphite, amorphous carbon, graphene, diamond, activated carbon, ordered mesoporous carbon, disordered mesoporous carbon, carbon fiber, carbon nanotube, and carbon microtube.

6 . The method for preparing a hollow foam material according to claim 1 , wherein the thickening treatment in step (1) is selected from one or more of the following: thickening by electroplating and thickening by electroless plating. 7 . , sol-gel method.

7 . The method for preparing a hollow foam material according to claim 1 , wherein the thickening treatment in step (1) is carried out as follows: according to the mass ratio of main component: solvent=100: (50-200) The thickening slurry is prepared, the initial template material is dipped into the thickening slurry, and the operation of dipping-removing excess slurry-semi-curing is carried out in a cycle until the thickness of the skeleton rib reaches the required size of the inner diameter of the hollow microchannel of 0.02mm to 9mm; wherein , the main component of the thickening slurry is selected from one or more of the following substances: polyurethane, phenolic resin, epoxy resin, furan resin, polyvinyl alcohol, polyvinyl butyral, isocyanate, modified isocyanate, Carboxymethyl cellulose, cellulose acetate, starch, aluminum oxide, magnesium oxide, silicon oxide, calcium oxide, ferric oxide, ferric oxide, cobalt oxide, manganese oxide, copper oxide, zinc oxide, tin oxide, oxide Nickel, graphite, amorphous carbon, graphene, diamond, activated carbon, ordered mesoporous carbon, disordered mesoporous carbon, carbon fiber, carbon nanotube, carbon microtube, urea, potassium salt, sodium salt, calcium salt, magnesium salt , aluminum salts, ferrous salts, iron salts, copper salts, manganese salts, nickel salts, zinc salts, ammonium salts, tartrate salts, bisulfite salts, sulfite salts, thiosulfate salts, halide salts, sulfonate salts , Salicylate, Benzoate, Acetate, Phosphate, Carbonate, Bicarbonate, Lactate, Sulfate, Nitrate, Li, Na, K, Al, Ca, Sr, Mg, Elemental metals of Ni, Fe, Cu, V, Cr, Mo, W, Mn, Co, Zn, Y, Zr, Nb, Ag, Pd, Ru, Rh, Au, Pt, Ta, lanthanide, and actinide , an alloy, solid metal solution or intermetallic compound containing the above elements; the solvent is selected from one or more of the following: water, ethanol, acetone, ethylene glycol, cyclohexane, n-hexane, toluene, xylene, and tetrahydrofuran.

8 . The preparation method of the hollow foam material according to claim 1 , wherein in step (2), the green layer slurry of the micro-channel tube wall is composed of main component powder, binder, curing agent, The solvent is made according to the ratio of 50～500g: 50～200g: (greater than 0 to 0.2) times the mass of the binder: 1000mL, and is fully ball-milled and mixed;

Wherein, the main component powder is selected from one or more of metals, ceramics, polymers or carbon materials;

The metal material is selected from the group consisting of Li, Na, K, Al, Ca, Sr, Mg, Ni, Fe, Cu, V, Cr, Mo, W, Mn, Co, Zn, Y, Zr, Nb, Ag, Pd One or more of Ru, Rh, Au, Pt, Ta, lanthanide metals, actinide metals, alloys containing the above elements, metal solid solutions or intermetallic compounds;

The ceramic material is selected from one or more of the following: (1) oxides and composite oxides: Al ₂ O ₃ , SiO ₂ , ZrO ₂ , MgO, CaO, BeO, SrO, NiO, CuO, TiO ₂ , V ₂ O ₅ , Fe ₃ O, RuO ₂ , WO ₃ , ZnO, SnO ₂ , CdO, Nb ₂ O ₅ , PbO, Pb ₃ O ₄ , Bi ₂ O ₃ , MoO ₃ , Cr ₂ O ₃ , Y ₂ O ₃ , MnO, MnO ₂ , Mn ₂ O ₃ , Mn ₃ O ₄ , CoO, Co ₃ O ₄ , Co ₂ O ₃ , lanthanide oxides, actinide oxides; mullite (3Al ₂ O ₃ ·2SiO ₂ ), aluminum magnesium spinel (MgO 3Al ₂ O ₃ ), magnesia chrome spinel (MgO Cr ₂ O ₃ ), zircon (ZrO ₂ SiO ₂ ), calcium orthosilicate (2CaO SiO 2 ) ₂ ), forsterite (2MgO·SiO ₂ ), perovskite composite oxides (CaTiO ₃ or doped CaTiO ₃ , BaTiO ₃ or doped BaTiO ₃ , LiNbO ₃ or doped LiNbO ₃ , SrZrO ₃ Or doped SrZrO ₃ , LaMnO ₃ or doped LaMnO ₃ , doped SrCo _y Fe _1-y O _3-δ , 0<y<1, 0<δ<3, La _x A ₁ substituted at A site _- _x Co _y Fe _1-y O _3-δ , where A=Sr, Ba, Ca, 0<x<1, 0<y<1, 0<δ<3); (2) Carbide: silicon carbide, Zirconium carbide, tungsten carbide, titanium carbide, boron carbide, tantalum carbide, vanadium carbide, chromium carbide, niobium carbide, molybdenum carbide, iron carbide, manganese carbide; (3) Nitride: α-Si ₃ N ₄ , β-Si ₃ N ₄ , AlN, Si _6-x Al _x O _x N _8-x , BN; (4) Si;

The polymer material is selected from one or more of the following: (1) Polyolefins: polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polypropylene, polyvinyl chloride, polystyrene, Polyacrylonitrile; (2) Polyamides: polycaprolactam (PA6), polyhexamethylene sebacate (PA610), polyundecalactam (PA11), polyhexamethylene dodecanediamide (PA612), Polysebacic acid decanediamine (PA1010); (3) Polyesters: polyurethane, polymethyl methacrylate, polyisocyanurate, polycarbonate, polydibutyl terephthalate, polypara Ethylene phthalate (4) Polyethers: polyphenylene ether, polyphenylene sulfide;

The carbon material is selected from one or more of the following: graphite, amorphous carbon, graphene, diamond, activated carbon, ordered mesoporous carbon, disordered mesoporous carbon, carbon fiber, carbon nanotube, carbon microtube ;

The binder is polyvinyl alcohol, polyvinyl butyral, carboxymethyl cellulose, chitosan, alginic acid, sodium alginate, epoxy resin, phenolic resin, furan resin, polyurethane, polycarbosilane, polyboron One or more of azane, polyborosiloxane, polyborosilazane, and polyzirconium borosilazane;

The curing agent is formaldehyde, glutaraldehyde, terephthalaldehyde, water-soluble amine-formaldehyde condensate, dimethyl urea, trimethyl melamine, dimethyl ethyl urea, sodium sulfate, zinc sulfate, boric acid, Borax, silane crosslinking agent, dichromate, chromium nitrate, chromium complex, cuprammonium hydroxide, urea, melamine, phenol, polyisocyanate, diethyl oxalate, dimethyl oxalate, propylene glycol, Organic titanium, epichlorohydrin, chloroethanol, sodium tetraborate, N-methylol acrylamide, N,N'-methylenebisacrylamide, β-cyclodextrin, isopropylacrylamide, acrylamide, Acrylic acid, methyl methacrylate, vanillin, genipin, glyoxal, poly(N-ethylene glycol)-acetaldehyde, polyacrylonitrile, succinic acid and its derivatives, glycine, lysine, Diisocyanatohexane, trimellitic anhydride, brominated decane, p-azidobenzoic acid, heparin, ethylene glycol diglycidyl ether, chloromethoxypropane, acetic acid, citric acid, formic acid, glycolic acid , lactic acid, hydroxysuccinic acid, propionic acid, fatty acid, sodium citrate, calcium chloride, polyethylene glycol, fatty diamines, polyamines, aromatic polyamines, dicyandiamide , imidazoles, modified amines, boron trifluoride and complexes, low molecular polyamide, hexamethylenetetramine, benzenesulfonyl chloride, p-toluenesulfonyl chloride, ethyl sulfate, petroleum sulfonic acid, p- Toluenesulfonic acid, sodium p-toluenesulfonate, paraformaldehyde, sodium hydroxide, glycerol acetate, propylene carbonate, methylol urea, sulfuric acid, hydrochloric acid, phosphoric acid, oxalic acid, adipic acid, benzenesulfonic acid, phthalic anhydride, horse One or more of leic anhydride, 3,3'-dichloro-4,4'-diaminodiphenylmethane and divinylbenzene;

9 . The method for preparing a hollow foam material according to claim 1 , wherein the green layer slurry of the micro-channel tube wall described in step (2) further contains a pore-forming agent to regulate the pores of the micro-channel tube wall. 10 . structure.

10. according to the preparation method of the hollow foam material of claim 9, it is characterized in that, described regulation and control step is preferably: (1) pore former is selected from metal pore former, oxide pore former, polymer pore former One or more of the pore-forming agent, inorganic salt pore-forming agent and carbon material pore-forming agent, the particle size of the pore-forming agent is 1 nm to 100 μm, and the pore-forming agent is added in an amount equal to the total mass of the green layer slurry of the micro-channel tube wall 0.001% to 20% of the pore-forming agent; (2) use the slurry of the green layer of the microchannel tube wall containing the same or different pore-forming agents in stages and in turn to carry out the cycle operation of "impregnating slurry-removing excess slurry-semi-curing" , forming a foam material preform with a homogeneous or heterogeneous microchannel wall green layer.

11 . The method for preparing a hollow foam material according to claim 1 , wherein the structure of the green layer of the microchannel tube wall described in step (2) can be partially porous, uniform or completely non-porous. 12 . structure.

12 . The method for preparing a hollow foam material according to claim 11 , wherein the pores are removed by any one of steps (3), (4) and (5) or a combination of two or more steps, 12 . Further, a hollow foam material with a dense structure microchannel wall is prepared.

13 . The preparation method of the hollow foam material according to claim 1 , further comprising a functional modification process after step (5), that is, by electroplating, electroless plating, solution etching, and anodizing. 14 . , sol-gel method, hydrothermal reaction method, vapor phase inversion method, Langmuir-Blodgett method, physical vapor deposition method, chemical vapor deposition method, one or more of the outer wall surface, inner wall surface, Or the nanopores or micropores contained in the tube wall itself are functionalized and modified.

14. The application of the hollow foam material obtained by the preparation method according to any one of claims 1 to 13, wherein the hollow foam material is used in any of the following fields: membrane separation material, reaction separation material, filter material, Extraction separation materials, reactive extraction separation materials, catalytic carrier materials, microreactors, micro heat exchange materials, composite reinforcements, electrode materials, sound absorption/noise reduction materials, thermal insulation materials, fluid distribution materials, materials for reactive fractionation, Materials for reactive distillation, and fixed valves in fractionation/rectification towers.