CN100398614C - Solvent-free inorganic nanoparticle fluid and preparation method thereof - Google Patents

Abstract

A solvent-free inorganic nanoparticle fluid and a preparation method thereof. The inorganic nanoparticle fluid is a long-chain organosilicon quaternary ammonium salt grafted on the surface of the inorganic nanoparticle. Inorganic nanoparticles include nano silicon dioxide, nano iron oxide, nano calcium carbonate, nano titanium dioxide and nano carbon black. Through the long-chain structure of organic silicon quaternary ammonium salts and the electrostatic repulsion of organic ion salts, the inorganic nanoparticles have fluidity in a solvent-free state. This solvent-free nanoparticle fluid is a single-phase, solvent-free colloidal substance. This substance is not only applied to nanocomposite materials like conventional solid inorganic nanoparticles to achieve toughening and strengthening of polymer materials, but also to realize self-assembly of nanomaterials like inorganic nanoparticles added to solvents; this inorganic nanoparticle Particle fluids show more significant application prospects in high-temperature lubrication, electromagnetic rheological fluids, proton exchange membranes for fuel cells, plasticization of polymer materials, and new reaction media.

Description

Solvent-free inorganic nanoparticle fluid and preparation method thereof

technical field

The invention relates to the technical field of surface modification of inorganic nanoparticles, in particular to the technology of grafting long-chain organic silicon quaternary ammonium salts on the surface of inorganic nanoparticles to prepare inorganic nanoparticles with fluid-like behavior under solvent-free conditions.

Background technique

Nanomaterials are new materials developed in the 1980s. Since their birth, they have been praised by the American Society for Materials as "the most promising materials in the 21st century" because of their wide application prospects. Nanoparticles are atomic groups or molecular groups composed of a small number of atoms or molecules. The surface atoms are an amorphous layer with neither long-term program nor short-term program; while in the core of the particle, there are well-crystallized periodic arrangements. atom. Due to the special structure of nanoparticles, nanomaterials have special characteristics such as surface effect, volume effect, quantum size effect and macroscopic quantum tunneling effect, and thus produce many physical and chemical properties different from conventional solids. However, while having these excellent properties, due to the small size of nanoparticles, the huge surface energy makes it easy to agglomerate. After the aggregation of inorganic nanoparticles, many excellent properties of nanomaterials will be destroyed. Therefore, the surface treatment of inorganic particles must be carried out during application to stabilize primary particles or smaller aggregates and prevent agglomeration from occurring.

At present, there are many methods for surface treatment of inorganic nanoparticles. According to whether there is a chemical reaction between the surface treatment agent and the particles, it can be divided into two categories: adsorption encapsulation modification and surface chemical modification. Commonly used adsorption and encapsulation modifiers are generally polymer materials, such as polymer dispersants. Through the electrostatic combination of the functional groups on the polymer dispersant or the active functional groups contained in the surface layer of nanoparticles, the dispersant is fixed on the particle surface to form a package. There are two main methods: (1) polymer deposition and adsorption in solution or melt (2) Polymerization after monomer adsorption and encapsulation. Surface chemical modification can generate stronger interaction forces between the modification and the nanoparticles. There are three main methods of chemical treatment: (1) Surfactant method. Use the organic functional groups of the surfactant to carry out chemical adsorption or chemical reaction with the particle surface, so that the surfactant covers the particle surface; (2) Plasma and radiation-induced polymerization modification. Using methods such as high-energy radiation and plasma treatment, the surface of inorganic particles is combined with hydroxyl groups to generate active species with initiating activity to initiate polymerization of monomers on the surface; (3) Graft polymerization modification on the surface of particles. Through the coupling reaction on the surface of inorganic particles, directly polymerizable organic groups are attached, or the organic groups that can generate free radicals are grafted on the surface of inorganic substances to various polymers.

The surface modification methods of these nanoparticles above basically solve the problem of self-agglomeration of nanoparticles due to surface energy, and better solve the compatibility problem between inorganic nanoparticles and polymer matrix. materials are widely used. However, a common problem of these modification methods is that the modified inorganic nanoparticles still exist in a solid state under solvent-free conditions. Inorganic nanoparticles in this solid state are usually used as fillers in polymer/inorganic nanoparticle composites; in other fields, such as self-assembly of nanoparticles, inorganic nanoparticles must be added to solvents, sometimes inorganic nanoparticles liquid Concentrations up to 50%. Therefore, the application field of this solid-state inorganic nanoparticle is greatly limited. If inorganic nanoparticles have fluid flow behavior under solvent-free conditions, it will undoubtedly greatly broaden the application of inorganic nanoparticles. However, the research on solvent-free inorganic nanoparticle fluids has not been reported at home and abroad.

Contents of the invention

The purpose of the present invention is to provide a kind of inorganic nanoparticles with fluid behavior under solvent-free conditions, and provide a preparation method of the solvent-free inorganic nanoparticle fluid.

The inorganic nanoparticles involved in the present invention include nano silicon dioxide, nano iron oxide, nano calcium carbonate, nano titanium dioxide and nano carbon black.

In order to achieve the above purpose, the present invention grafts long-chain organosilicon quaternary ammonium salts on the surface of inorganic nanoparticles to modify the surface of the inorganic nanoparticles. Through the long-chain structure of organosilicon quaternary ammonium salt and the electrostatic repulsion of organic ion salt, inorganic nanoparticles have fluidity in a solvent-free state, which is a kind of solvent-free inorganic nanoparticle fluid. This solvent-free nanoparticle fluid is different from the traditional nanoparticle solution. It is a single-phase, solvent-free colloidal substance. A large number of organic long chains grafted on the surface have good flexibility and are easy to synthesize inorganic nanoparticles. At the same time, the electrostatic force interaction of long-chain counterions makes inorganic nanoparticles have flow properties under solvent-free conditions. This solvent-free inorganic nanoparticle fluid can not only be applied to nanocomposite materials like conventional solid inorganic nanoparticles to achieve toughening and strengthening of polymer materials, but also like inorganic nanoparticles added with solvents to achieve nanomaterials Self-assembly; moreover, this solvent-free inorganic nanoparticle fluid shows more significant application prospects in the fields of high-temperature lubrication, electromagnetic rheological fluid, proton exchange membrane for fuel cells, plasticization of polymer materials, and new reaction media.

Realize the technical scheme of the present invention as:

A solvent-free inorganic nanoparticle fluid, characterized in that the solvent-free inorganic nanoparticle fluid is an organosilicon quaternary ammonium salt grafted with a long chain on the surface of the inorganic nanoparticle, and is prepared by the following method steps,

Step 1. According to the number of parts by mass, 100 parts of inorganic nanoparticles and 20 to 100 parts of organic silicon quaternary ammonium salt methanol solution with a mass percentage of 30% to 60%, the molecular formula is (CH ₃ O) ₃ Si(CH ₂ ) _n N ⁺ (CH ₃ )(C ₁₀ H ₂₁ ) ₂ Cl ^- (n=1~20), add into the reactor, ultrasonically disperse for 10~50 minutes, react at 0℃~200℃ for 12~60 hours After the reaction, the resultant is repeatedly washed with deionized water and methanol, and then dried for 24 to 48 hours to obtain an inorganic nanoparticle organic ion salt;

Step 2. Add 20 to 100 parts of sulfonate in parts by mass to 100 parts of inorganic nanoparticle organic ion salt obtained in step 1, the molecular formula is R-(OCH ₂ CH ₂ ) _m -O(CH ₂ ) ₃ SO ₃ ^- K ⁺ (R=C ₁ -C ₁₅ , m=1~60), react at 0°C~200°C for 12~60 hours, collect the product and extract it with toluene, repeat it several times and then cool it at 30°C~100°C Under rotary evaporation, the residue is dispersed in acetone, centrifuged, and finally vacuum-dried to obtain a gel-like solvent-free inorganic nanoparticle fluid;

Wherein, the inorganic nanoparticles are nano-silicon dioxide, nano-iron oxide, nano-calcium carbonate, nano-titanium dioxide or nano-carbon black.

The preparation method step of a class of solvent-free inorganic nano particle fluid of the present invention is:

Step 1. According to the number of parts by mass, 100 parts of inorganic nanoparticles and 20 to 100 parts of organic silicon quaternary ammonium salt methanol solution with a mass percentage of 30% to 60%, the molecular formula is (CH ₃ O) ₃ Si(CH ₂ ) _n N ⁺ (CH ₃ )(C ₁₀ H ₂₁ ) ₂ Cl ^- (n=1~20), add into the reactor, ultrasonically disperse for 10~50 minutes, react at 0℃~200℃ for 12~60 hours After the reaction, the resultant is repeatedly washed with deionized water and methanol, and then dried for 24 to 48 hours to obtain an inorganic nanoparticle organic ion salt;

Step 2. Add 20 to 100 parts of sulfonate in parts by mass to 100 parts of inorganic nanoparticle organic ion salt obtained in step 1, the molecular formula is R-(OCH ₂ CH ₂ ) _m -O(CH ₂ ) ₃ SO ₃ ^- K ⁺ (R=C ₁ -C ₁₅ , m=1~60), react at 0°C~200°C for 12~60 hours, collect the product and extract it with toluene, repeat it several times and then cool it at 30°C~100°C Under rotary evaporation, the residue is dispersed in acetone, centrifuged, and finally vacuum-dried to obtain a gel-like solvent-free inorganic nanoparticle fluid;

Wherein, the inorganic nanoparticles are nano-silicon dioxide, nano-iron oxide, nano-calcium carbonate, nano-titanium dioxide or nano-carbon black.

Detailed ways

Embodiment 1: in parts by mass, 100 parts of nano-calcium carbonate (5～40 nanometers) and 20 parts of mass percent content are 50% organosilicon quaternary ammonium salt methanol solution, and its molecular formula is (CH ₃ O) ₃ Si (CH ₂ ) ₃ N ⁺ (CH ₃ )(C ₁₀ H ₂₁ ) ₂ Cl ^- , ultrasonically dispersed for 30 minutes, and reacted at 100±5°C for 48 hours. After the reaction, the product was repeatedly washed with deionized water and methanol Washing, and then drying for 24 hours, to obtain nanometer calcium carbonate salt with good flexibility and long chain grafted on the surface. In parts by mass, add 20 parts of sulfonate to 100 parts of the obtained inorganic nanoparticle organic ion salt, the molecular formula is R-(OCH ₂ CH ₂ ) _m -O(CH ₂ ) ₃ SO ₃ ^- K ⁺ (R= C ₁ -C ₁₅ , m=1～60), reacted at 100±5°C for 48 hours, collected the product and extracted it with toluene, after repeated several times, the raffinate phase was rotary evaporated at 70±5°C, and the residue was dispersed In acetone, centrifugal separation, and finally vacuum drying to obtain gel-like nanometer calcium carbonate particle fluid.

Embodiment 2: in parts by mass, 100 parts of nanometer silicon dioxide (5～20 nanometers) and 100 parts of mass percentage composition are 30% organosilicon quaternary ammonium salt methanol solution, and its molecular formula is (CH ₃ O) ₃ Add Si(CH ₂ ) ₆ N ⁺ (CH ₃ )(C ₁₀ H ₂₁ ) ₂ Cl ^- into a three-necked flask, ultrasonically disperse for 20 minutes, and react at 20±2°C for 60 hours. After the reaction, use the Repeated washing with deionized water and methanol, and then drying for 24 hours, to obtain nanometer silicon dioxide salt grafted on the surface with good flexibility and long chains. In parts by mass, add 100 parts of sulfonate to 100 parts of the obtained nano silicon dioxide salt, the molecular formula is C ₉ H ₁₉ -(OCH ₂ CH ₂ ) _6～9 -O(CH ₂ ) ₃ SO ₃ ^{-K +} , reacted at 30±5°C for 60 hours; collected the product and extracted it with toluene, repeated several times, then the raffinate phase was rotary evaporated at 95±5°C, dispersed the residue in acetone, centrifuged, and finally dried in vacuum A gel-like nano silicon dioxide particle fluid is obtained.

Embodiment 3: in parts by mass, 100 parts of nano-titanium dioxide (10-30 nanometers) and 50 parts of organic silicon quaternary ammonium salt methanol solution having a molecular formula of (CH ₃ O) ₃ Si ( CH ₂ ) ₈ N ⁺ (CH ₃ )(C ₁₀ H ₂₁ ) ₂ Cl ^- , put into a three-necked flask, ultrasonically disperse for 50 minutes, and react at 120±5°C for 50 hours. After the reaction, use a deionized Washing with water and methanol repeatedly, and then drying for 24 hours, the surface grafted nano-titanium dioxide salt with good flexibility and long chains is obtained. In parts by mass, 50 parts of sulfonate were added to 100 parts of nano-titanium dioxide salt obtained, the molecular formula of which was C ₉ H ₁₈ -(OCH ₂ CH ₂ ) ₁₀ -O(CH ₂ ) ₃ SO ₃ ^{-K +} , in React at 20±5°C for 48 hours. The collected product was extracted with toluene, and after repeated several times, the raffinate phase was rotatably evaporated at 70±5°C, the residue was dispersed in acetone, centrifuged, and finally vacuum-dried to obtain a gel-like nano-titanium dioxide particle fluid.

Example 4: In parts by mass, 100 parts of nano-iron oxide (5-40 nanometers) and 80 parts by mass of 50% organosilicon quaternary ammonium salt methanol solution, whose molecular formula is (CH ₃ O) ₃ Si (CH ₂ ) ₃ N ⁺ (CH ₃ )(C ₁₀ H ₂₁ ) ₂ Cl ^- , put into a three-necked flask, ultrasonically disperse for 30 minutes, and react at 150±10°C for 12 hours. After the reaction, use up the product Repeated washing with ionic water and methanol, and then drying for 24 hours, to obtain nano-iron oxide salts with good flexibility and long chains grafted on the surface. In parts by mass, add 40 parts of sulfonate to 100 parts of the obtained nano iron oxide salt, the molecular formula of which is C ₉ H ₁₉ -(OCH ₂ CH ₂ ) ₁₅ -O(CH ₂ ) ₃ SO ₃ ^- K ⁺ , React at 100±5°C for 48 hours. Collect the product and extract it with toluene. After repeated several times, the raffinate phase is rotated and evaporated at 60±5°C. The residue is dispersed in acetone, centrifuged, and finally vacuum-dried to obtain a gel-like nano-iron oxide particle fluid.

Embodiment 5: in parts by mass, 100 parts of nano carbon black (5 ~ 40 nanometers) and 30 parts by mass percentage are 60% organosilicon quaternary ammonium salt methanol solution, and its molecular formula is (CH ₃ O) ₃ Si Add (CH ₂ ) ₃ N ⁺ (CH ₃ )(C ₁₀ H ₂₁ ) ₂ Cl ^- into a three-necked flask, ultrasonically disperse for 30 minutes, and react at 130±10°C for 48 hours. After the reaction is complete, use up the product Repeated washing with ionized water and methanol, and then drying for 24 hours, to obtain nano-carbon black salt with good flexibility and long chain grafted on the surface. In parts by mass, 30 parts of sulfonate were added to 100 parts of the obtained nano carbon black salt, and its molecular formula was C ₉ H ₁₉ -(OCH ₂ CH ₂ ) ₃₀ -O(CH ₂ ) ₃ SO ₃ ^{-K +} , React at 50±2°C for 48 hours. The collected product was extracted with toluene, and after several repetitions, the raffinate phase was rotatably evaporated at 70±5°C, the residue was dispersed in acetone, centrifuged, and finally vacuum-dried to obtain a gel-like nano-carbon black particle fluid.

Claims (2)

1. a class solvent-free inorganic nano particle fluid is characterized in that, such solvent-free inorganic nano particle fluid is the organosilicon quaternary ammonium salt of inorganic nano-particle surface grafting long-chain, adopts following method steps to make,

Step 1, pressing mass fraction, is 30%～60% organosilicon quaternary ammonium salt methanol solution with 100 parts of inorganic nano-particles and 20～100 parts of quality percentage compositions, and its molecular formula is (CH ₃O) ₃Si (CH ₂) _nN ⁺(CH ₃) (C ₁₀H ₂₁) ₂Cl ^-N=1～20 add in the reactor, and ultra-sonic dispersion 10～50 minutes reacted 12～60 hours down at 0 ℃～200 ℃, after having reacted, resultant with deionized water and methyl alcohol repetitive scrubbing, dry 24～48 hours then, are obtained inorganic nano-particle organic ion salt;

Step 2, press mass fraction, add 20～100 parts of sulfonate in 100 portions of inorganic nano-particle organic ion salt that step 1 obtains, molecular formula is R-(OCH ₂CH ₂) _m-O (CH ₂) ₃SO ₃ ^-K ⁺R=C ₁-C ₁₅, reacted 12～60 hours down at 0 ℃～200 ℃ m=1～60, collect resultant and extract with toluene, the back is scattered in residuum in the acetone at 30 ℃～100 ℃ following rotary evaporations several times repeatedly, centrifugation is after vacuum-drying obtains gelatinous solvent-free inorganic nano particle fluid;

Wherein, described inorganic nano-particle is nano silicon, nano-sized iron oxide, nano-calcium carbonate, nano titanium oxide or nanometer carbon black.

2. the preparation method of the described class solvent-free inorganic nano particle fluid of claim 1 is characterized in that, preparation process is:

Step 1, pressing mass fraction, is 30%～60% organosilicon quaternary ammonium salt methanol solution with 100 parts of inorganic nano-particles and 20～100 parts of quality percentage compositions, and its molecular formula is (CH ₃O) ₃Si (CH ₂) _nN ⁺(CH ₃) (C ₁₀H ₂₁) ₂Cl ^-N=1～20 add in the reactor, and ultra-sonic dispersion 10～50 minutes reacted 12～60 hours down at 0 ℃～200 ℃, after having reacted, resultant with deionized water and methyl alcohol repetitive scrubbing, dry 24～48 hours then, are obtained inorganic nano-particle organic ion salt;

Step 2, press mass fraction, add 20～100 parts of sulfonate in 100 portions of inorganic nano-particle organic ion salt that step 1 obtains, molecular formula is R-(OCH ₂CH ₂) _m-O (CH ₂) ₃SO ₃ ^-K ⁺R=C ₁-C ₁₅, reacted 12～60 hours down at 0 ℃～200 ℃ m=1～60, collect resultant and extract with toluene, the back is scattered in residuum in the acetone at 30 ℃～100 ℃ following rotary evaporations several times repeatedly, centrifugation is after vacuum-drying obtains gelatinous solvent-free inorganic nano particle fluid;

Wherein, described inorganic nano-particle is nano silicon, nano-sized iron oxide, nano-calcium carbonate, nano titanium oxide or nanometer carbon black.