CN107266942A - A kind of enhanced aerogel powder and preparation method thereof - Google Patents

Abstract

The invention discloses an enhanced airgel powder and a preparation method thereof, which is characterized in that the enhanced airgel powder is composed of an airgel powder and a coating material. The preparation method of an enhanced airgel powder provided by the present invention comprises the following steps: (1) modification of airgel powder; (2) preparation of coating slurry; (3) coating; (4) ) to cure. The enhanced airgel powder provided by the present invention and its preparation method have the characteristics of low cost, high efficiency, and continuous production. The airgel powder has mechanical properties while retaining the original excellent characteristics of the airgel. Good performance and other advantages, has a huge application prospect.

Description

A kind of reinforced airgel powder and preparation method thereof

technical field

The invention relates to the technical field of surface modification of inorganic nanoporous materials, in particular to an enhanced airgel powder and a preparation method thereof, and belongs to the field of light weight, heat preservation, fireproof, sound insulation, explosion-proof, shock-absorbing and energy-absorbing materials.

Background technique

Airgel is a light inorganic solid material with a three-dimensional network skeleton structure and nano-scale pores. It has extremely high porosity, specific surface area, extremely low density and solid content, chemical inertness and non-combustibility, and exhibits excellent Light weight, heat insulation, fire prevention, sound insulation, shock absorption and energy absorption and other characteristics, the thermal conductivity can be as low as 0.015W/m·K or less.

As a lightweight functional filler, airgel powder can be compounded with concrete, resin and other materials to produce composite materials with light weight, heat insulation, sound insulation and other properties. However, the special structural characteristics of aerogel lead to its low mechanical properties such as flexural resistance and compressive strength, and it is easily broken during the composite process with other materials; The siphon phenomenon is very easy to occur when the solvent is in contact, thereby destroying the nanopore structure of the airgel, resulting in the loss of its excellent properties.

Contents of the invention

The object of the present invention is to provide a reinforced airgel powder and a preparation method thereof.

An enhanced airgel powder is composed of an airgel powder and a coating material.

In one of the embodiments, the covering material is a water-based adhesive.

In one of the embodiments, the water-based adhesive is one or more of organic adhesives and inorganic adhesives; the organic adhesive is rosin resin, alkyd resin, acrylic resin, polyurethane resin, silicone resin, fluorocarbon resin , polyethylene resin, polystyrene resin, polyvinyl chloride resin, polypropylene resin, acrylonitrile-butadiene-styrene resin, etc.; the inorganic adhesive is cement, gypsum, limestone, water One or more of glass, copper oxide-phosphate glue, etc.

A kind of preparation method of enhanced airgel powder of the present invention, comprises the following steps:

(1) Airgel powder modification;

(2) Preparation of airgel composite slurry;

(3) Continuously flow the airgel composite slurry to the ultrasonic atomizing head, so that the airgel composite slurry is dispersed into an atomized body of airgel powder coated with water-based adhesive;

(4) Curing treatment.

In one of the embodiments, the step (1) includes a hydrophobic modification step; the hydrophobic modification step is to perform hydrophobic modification on the airgel powder in a closed hydrophobic modifier gas phase environment; the hydrophobic The modifier is trimethylchlorosilane, hexamethyldisilazane, hexamethyldisiloxane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, Dimethyldiethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-(2,3-glycidoxy)propyltrimethoxysilane, γ - One or more of methacryloxypropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltriethoxysilane.

In one of the embodiments, the step (1) further includes a surface hydrophilic modification step; the surface hydrophilic modification step is to use a surface hydrophilic modification solution to modify the surface of the hydrophobic airgel powder; The surface hydrophilic modification solution is an aqueous solution of a surfactant and a low surface tension solvent or an aqueous solution of a low surface tension solvent; the surfactant is an anionic surfactant, a cationic surfactant, an amphoteric surfactant, One or more of nonionic surfactants; the anionic surfactant is fatty alcohol phosphate ester salt, fatty alcohol polyoxyethylene ether phosphate ester salt, alkyl sulfate, fatty alcohol polyoxyethylene ether sulfuric acid Salt, Glycerin Fatty Acid Ester Sulfate, Sulfated Ricinoleate, Naphthene Sulfate, Fatty Amide Alkyl Sulfate, Alkylbenzene Sulfonate, Alkyl Sulfonate, Fatty Acid Methyl Ester Ethoxylate Sulfonic Acid One or more in salt, fatty acid methyl ester sulfonate, fatty alcohol polyoxyethylene ether carboxylate; Described cationic surfactant is aliphatic ammonium salt; Described amphoteric surfactant is alkyl amino acid, One or more of carboxylate betaine, sultaine, phosphate betaine, and alkyl hydroxyamine oxide; the nonionic surfactant is aliphatic polyester, alkylphenol polyoxyethylene ether , high-carbon fatty alcohol polyoxyethylene ether, fatty acid polyoxyethylene ester, fatty acid methyl ester ethoxylate, polypropylene glycol ethylene oxide adduct, sorbitan ester, sucrose fatty acid ester, alkyl ester amide One or more; the low surface tension solvent is one or more mixtures in acetone, n-hexane, n-pentane, n-heptane, ethanol, isopropanol, tert-butanol, propylene glycol, glycerin.

In one embodiment, the surface hydrophilic modification step further includes an external physical field action step; the external physical field action step is one of far-infrared radiation, stirring, ultrasonic treatment, and ball milling.

In one of the embodiments, the step (1) further includes a drying treatment step; the drying treatment step is far-infrared drying, spray drying, microwave drying, normal pressure drying, supercritical drying, subcritical drying, freeze drying kind of.

In one embodiment, the airgel composite slurry is prepared by mixing and stirring the airgel powder modified in step (1), water-based adhesive and water.

In one embodiment, the curing treatment is one or more of far-infrared radiation heating, microwave heating, ultraviolet radiation, natural curing, steam curing, and autoclaving curing.

The above-mentioned enhanced airgel powder has the structural characteristics of internal hydrophobicity and surface hydrophilicity, and can retain the original excellent characteristics of airgel, and has the advantages of high mechanical properties, particle size of micron level, uniform particle size distribution, etc. , can be used as a functional filler in coatings, adhesives, insulating materials, concrete and other fields; the invention can realize continuous, stable and efficient industrial production.

detailed description

In order to make the above objects, features and advantages of the present invention more obvious and comprehensible, specific implementations of the present invention will be described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, the present invention can be implemented in many other ways different from those described here, and those skilled in the art can make similar improvements without departing from the connotation of the present invention, so the present invention is not limited by the specific implementations disclosed below.

An embodiment of the enhanced airgel powder of the present invention is composed of airgel powder and a coating material.

In this way, when the airgel powder is combined with other materials, the nanoporous structure will not be destroyed by solvents such as water, and other materials can be tiled on the surface of the airgel powder, providing a prerequisite for the airgel powder to be combined with other materials condition.

In this embodiment, the covering material is a water-based adhesive.

In this way, the mechanical properties such as flexural strength and compressive strength of water-based adhesives are much higher than those of airgel, and the coating of gelling materials on the surface of airgel powder can significantly improve the performance of airgel while retaining the excellent performance of aerogel. Improve the mechanical properties of airgel powder and expand the engineering application of airgel powder.

In this embodiment, the water-based adhesive is one or more of organic adhesives and inorganic adhesives; the organic adhesive is rosin resin, alkyd resin, acrylic resin, polyurethane resin, silicone resin, fluorocarbon resin, polyester One or more of vinyl resin, polystyrene resin, polyvinyl chloride resin, polypropylene resin, acrylonitrile-butadiene-styrene resin, etc.; the inorganic adhesive is cement, gypsum, limestone, water glass, One or more of copper oxide-phosphate glue, etc.

In this way, different water-based adhesives have different mechanical properties and different maintenance and curing processes. Generally, compared with organic adhesives, inorganic adhesives have higher mechanical properties, but the maintenance and curing processes are complicated and the cycle is long. The present invention is based on airgel The mechanical properties required for the powder and the physical and chemical properties required for the surface of the airgel powder when it is combined with other materials, select a suitable water-based adhesive or a variety of water-based adhesives to compound and coat the airgel powder.

A preparation method of enhanced airgel powder, comprising the following steps:

(1) Airgel powder modification;

(2) Preparation of airgel composite slurry;

(3) Continuously flow the airgel composite slurry to the ultrasonic atomizing head, so that the airgel composite slurry is dispersed into an atomized body of airgel powder coated with water-based adhesive;

(4) Curing treatment.

In addition, the surface material of the atomizing head may have hydrophobic properties.

In this way, using ultrasonic atomization technology and ultrasonic atomization head surface hydrophobic technology, the airgel composite slurry is continuously flowed to the ultrasonic atomization head, using the cavitation explosion effect between the composite slurry and air and ultrasonic atomization Hydrophobic properties of the surface of the head, the composite slurry around the hole is crushed into a micron-sized atomized body of airgel surface coated with water-based adhesive; the present invention has internal hydrophobicity, surface hydrophilicity and surface-coated water through the above steps. The enhanced airgel powder with the structural characteristics of the adhesive can be used as a functional filler to compound with materials such as concrete and adhesives on the premise that the nanoporous structure is not destroyed.

In this embodiment, the step (1) includes a hydrophobic modification step; the hydrophobic modification step is to perform hydrophobic modification on the airgel powder in a closed hydrophobic modifier gas phase environment; the hydrophobic modification The agent is trimethylchlorosilane, hexamethyldisilazane, hexamethyldisiloxane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyl Diethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-(2,3-glycidoxy)propyltrimethoxysilane, γ-methyl One or more of acryloyloxypropyltrimethoxysilane and N-(β-aminoethyl)-γ-aminopropyltriethoxysilane.

In this way, due to the existing airgel preparation method, the precursor, the replacement solvent and the drying process have a great impact on the hydrophobicity of the airgel. If the contact angle between the surface of the airgel and water is greater than 90°, it is not necessary to Hydrophobic modification is carried out in advance, and the surface is directly modified to be hydrophilic; if the contact angle between the surface of the airgel and water is less than 90°, it is necessary to carry out hydrophobic modification in advance; Hydrophobic modification of rubber powder, in addition to significantly improving the modification effect of airgel powder and ensuring that the internal nanoporous structure is not damaged during subsequent hydrophilic modification, it also significantly improves modification efficiency and production efficiency, reducing production costs .

In this embodiment, the step (1) further includes a surface hydrophilic modification step; the surface hydrophilic modification step is to use a surface hydrophilic modification solution to modify the surface of the hydrophobic airgel powder; the The surface hydrophilic modification solution is an aqueous solution of a surfactant and a low surface tension solvent or an aqueous solution of a low surface tension solvent; the surfactant is an anionic surfactant, a cationic surfactant, an amphoteric surfactant, a nonionic One or more in type surfactant; Described anionic surfactant is fatty alcohol phosphate ester salt, fatty alcohol polyoxyethylene ether phosphate ester salt, alkyl sulfate, fatty alcohol polyoxyethylene ether sulfate, Glycerin Fatty Acid Ester Sulfate, Sulfated Ricinoleate, Naphthene Sulfate, Fatty Amide Alkyl Sulfate, Alkylbenzene Sulfonate, Alkyl Sulfonate, Fatty Acid Methyl Ester Ethoxylate Sulfonate, One or more of fatty acid methyl ester sulfonate, fatty alcohol polyoxyethylene ether carboxylate; the cationic surfactant is an aliphatic ammonium salt; the amphoteric surfactant is an alkyl amino acid, a carboxylic acid one or more of base betaine, sultaine, phosphate betaine, and alkyl hydroxyamine oxide; the nonionic surfactant is aliphatic polyester, alkylphenol polyoxyethylene ether, high One of carbon fatty alcohol polyoxyethylene ether, fatty acid polyoxyethylene ester, fatty acid methyl ester ethoxylate, polypropylene glycol ethylene oxide adduct, sorbitan ester, sucrose fatty acid ester, alkyl ester amide One or more; the low surface tension solvent is one or more of acetone, n-hexane, n-pentane, n-heptane, ethanol, isopropanol, tert-butanol, propylene glycol, glycerin.

In this way, the aqueous solution of surfactant and low surface tension solvent or the aqueous solution of low surface tension solvent has surface synergistic hydrophilic modification effect in the process of hydrophilic modification treatment on the surface of hydrophobic airgel powder, which can significantly improve The wetting and spreading rate of the surface hydrophilic modification solution on the surface of the airgel powder, and at the same time significantly slow down the wetting and spreading to the interior of the airgel powder. By adjusting the amount of the modification solution, the airgel can be accurately Control of the thickness of the hydrophilic layer on the surface of the powder. The low surface tension solvent not only has a surface synergistic hydrophilic modification effect with water and surfactants, but also can greatly reduce the hydrophilic modification that enters the nanopores on the surface of the airgel powder. The capillary force of the solution can easily evaporate the hydrophilic modification solution in the nanopores on the surface of the airgel powder through the drying process without destroying its nanoporous structure. The airgel powder of the present invention presents internal hydrophobicity, surface Hydrophilic, the surface hydrophilic layer still retains the structural characteristics of nanoporous structure and the thickness of the surface hydrophilic layer is 0.1~100μm, and has a good interface bonding with the gelled material; the process has simple steps, short cycle time, high production efficiency, etc. Features, suitable for industrial production.

In this embodiment, the surface hydrophilic modification step further includes an external physical field action step; the external physical field action step is one of far-infrared radiation, stirring, ultrasonic treatment, and ball milling.

In this way, the external physical field can significantly increase the activity of the surface hydrophilic modification solution and the contact probability with the airgel powder, reduce the amount of surfactant, increase the surface hydrophilic modification rate of the airgel powder, and reduce the cost ,Increase productivity.

In this embodiment, the step (1) further includes a drying treatment step; the drying treatment step is one of far-infrared drying, spray drying, microwave drying, normal pressure drying, supercritical drying, subcritical drying, and freeze drying. kind.

In this way, if the airgel powder after hydrophilic modification is combined with the gelling material, the residual hydrophilic modification solution on the surface will affect the interface bonding, and it needs to be dried in advance; Under the premise that the nanopore structure of the surface layer of the body is not destroyed, the residual surface hydrophilic modification solution in the nanopores of the surface layer of the airgel powder is evaporated to improve the interface bonding strength between the airgel powder and the gelling material.

In this embodiment, the airgel composite slurry is prepared by mixing and stirring the airgel powder modified in step (1), water-based adhesive and water.

In this way, the airgel powder with internal hydrophobicity and surface hydrophilicity is fully contacted and mixed with the water-based adhesive to form a good bonding interface in the liquid phase.

In this embodiment, the curing treatment is one or more of far-infrared radiation heating, microwave heating, ultraviolet radiation, natural curing, steam curing, and autoclaving curing.

In this way, it is ensured that the atomized body coated with the water-based adhesive on the surface of the airgel is cured before falling into the collection vessel, and the mechanical properties of the water-based adhesive coating are further improved.

The above-mentioned enhanced airgel powder has the structural characteristics of internal hydrophobicity and surface hydrophilicity, and can retain the original excellent characteristics of airgel, and has the advantages of high mechanical properties, particle size of micron level, uniform particle size distribution, etc. , can be used as a functional filler in coatings, adhesives, insulating materials, concrete and other fields; the invention can realize continuous, stable and efficient industrial production.

The following is the specific embodiment part.

Example 1

The following steps are used to prepare reinforced SiO ₂ airgel powder with internal hydrophobicity, surface hydrophilicity and polyurethane film coating on the surface. The thickness of the polyurethane coating layer is 8-10 μm:

(1) Use a contact angle measuring instrument to detect the contact angle between the surface of the SiO ₂ airgel powder to be treated and water. The test result is 55°, and then place the SiO ₂ airgel powder with a particle size of 56 μm in a vacuum heating In the furnace, place the weighed hexamethyldisilazane in a vacuum heating furnace with a container, heat and gasify, and perform hydrophobic modification for 1.5h to obtain hydrophobic _SiO2 airgel powder, which is detected by a contact angle meter The contact angle between the surface of hydrophobic SiO ₂ airgel powder and water is 147°;

(2) At room temperature, weigh ethanol, n-hexane and deionized water at a mass ratio of 1:1:100, mix them evenly, and prepare a surface hydrophilic modification solution;

(3) According to the volume ratio of hydrophobic SiO ₂ airgel powder and surface hydrophilic modification solution 1:3, weigh the surface modification solution, and pour it into the corresponding container, and put the hydrophobic SiO ₂ after step (1) The airgel powder is mixed with the surface hydrophilic modification solution, and after ball milling for 25 minutes, it is taken out and filtered;

(4) Place the SiO ₂ airgel powder with hydrophilic modification solution on the surface obtained in step (3) in a far-infrared drying oven, dry at 120°C for 0.5h, and cool down to below 50°C with the furnace After taking it out, the cross-section of the _SiO2 airgel powder is detected, and the detection results show that the thickness of the surface hydrophilic layer is 7.9 μm;

(5) Weigh the SiO ₂ airgel, water-based polyurethane resin and deionized water in step (4) according to the mass ratio of 1:30:100, stir and mix to obtain the SiO ₂ airgel composite slurry;

(6) Set the ultrasonic vibration frequency to 1 GHz, open the valve, so that the SiO ₂ airgel composite slurry flows to the ultrasonic vibration table, and atomize the SiO ₂ airgel composite slurry to obtain an atomized body. During the falling process, it is heated by far-infrared radiation and solidified to obtain enhanced SiO ₂ airgel powder, and the thickness of the polyurethane coating layer is 8-10 μm.

Example 2

The following steps were used to prepare reinforced _SiO2 airgel powders with internal hydrophobicity, surface hydrophilicity, and surface coating with acrylic film, and the thickness of the acrylic coating layer was 8-12 μm:

(1) Use a contact angle measuring instrument to detect the contact angle between the surface of the SiO ₂ airgel powder to be treated and water. The test result is 45°, and then place the SiO ₂ airgel powder with a particle size of 0.1mm in a vacuum In the heating furnace, use a container to place the weighed trimethylchlorosilane in a vacuum heating furnace, heat and gasify, and perform hydrophobic modification for 1.5 hours to obtain hydrophobic _SiO2 airgel powder, and use a contact angle meter to detect the hydrophobicity. The contact angle between the surface of SiO ₂ airgel powder and water is 146°;

(2) At room temperature, weigh n-hexane, acetone and deionized water at a mass ratio of 1:1:100, mix them evenly, and prepare a surface hydrophilic modification solution;

(3) According to the volume ratio of hydrophobic SiO ₂ airgel powder and surface hydrophilic modification solution 1:3, weigh the surface modification solution, and pour it into the corresponding container, and put the hydrophobic SiO ₂ after step (1) The airgel powder is mixed with the surface hydrophilic modification solution, and after mechanical stirring for 15 minutes, the rotating speed is 2500 rpm, and then filtered;

(4) Place the SiO ₂ airgel powder with hydrophilic modification solution on the surface obtained in step (3) in a far-infrared drying oven, dry at 120°C for 0.5h, and cool down to below 50°C with the furnace After taking it out, the cross-section of the _SiO2 airgel powder is detected, and the detection results show that the thickness of the surface hydrophilic layer is 11.1 μm;

(5) Weigh the SiO ₂ airgel, water-based acrylic resin and deionized water in step (4) according to the mass ratio of 1:40:100, stir and mix to obtain the SiO ₂ airgel composite slurry;

(6) Set the ultrasonic vibration frequency to 2 GHz, open the valve, so that the SiO ₂ airgel composite slurry flows to the ultrasonic vibration table, and atomize the SiO ₂ airgel composite slurry to obtain an atomized body. During the falling process, it is heated by far-infrared radiation and cured to obtain enhanced SiO ₂ airgel powder, and the thickness of the acrylic coating layer is 8-12 μm.

Example 3

The following steps were used to prepare reinforced SiO ₂ airgel powders with internal hydrophobicity, surface hydrophilicity and polyurethane film coating on the surface. The thickness of the polyurethane coating layer was 7-11 μm:

(1) Use a contact angle measuring instrument to detect the contact angle between the surface of the SiO ₂ airgel powder to be treated and water. The test result is 45°, and then place the SiO ₂ airgel powder with a particle size of 89 μm in a vacuum heating In the furnace, place the weighed hexamethyldisilazane in a vacuum heating furnace with a container, heat and gasify, and perform hydrophobic modification for 1.5h to obtain hydrophobic _SiO2 airgel powder, which is detected by a contact angle meter The contact angle between the surface of hydrophobic SiO ₂ airgel powder and water is 146°;

(2) At room temperature, weigh sodium alkylbenzenesulfonate, n-hexane and deionized water at a mass ratio of 1:0.8:120, mix them evenly, and prepare a surface hydrophilic modification solution;

(3) According to the volume ratio of hydrophobic SiO ₂ airgel powder and surface hydrophilic modification solution 1:3, weigh the surface modification solution, and pour it into the corresponding container, and put the hydrophobic SiO ₂ after step (1) The airgel powder is mixed with the surface hydrophilic modification solution, and after mechanical stirring for 15 minutes, the rotating speed is 2000 rpm, and then filtered;

(4) Place the SiO ₂ airgel powder with hydrophilic modification solution on the surface obtained in step (3) in a blast drying oven, dry at 120°C for 0.5h, and cool down to below 50°C with the furnace After taking it out, the cross-section of the _SiO2 airgel powder is detected, and the detection results show that the thickness of the surface hydrophilic layer is 6.0 μm;

(5) Weigh the SiO ₂ airgel, water-based polyurethane UV curing resin and deionized water in step (4) according to the mass ratio of 1:30:100, stir and mix to obtain the SiO ₂ airgel composite slurry;

(6) Set the ultrasonic vibration frequency to 1.2 GHz, open the valve, so that the SiO ₂ airgel composite slurry flows to the ultrasonic vibration table, and atomize the SiO ₂ airgel composite slurry to obtain an atomized body. During the falling process of the body, it is treated with ultraviolet radiation and cured to obtain enhanced SiO ₂ airgel powder, and the thickness of the polyurethane coating layer is 7-11 μm.

Example 4

The following steps were used to prepare reinforced SiO ₂ airgel powders with internal hydrophobicity, surface hydrophilicity, and epoxy resin film coating on the surface. The thickness of the epoxy resin coating layer was 13-15 μm:

(1) Use a contact angle measuring instrument to detect the contact angle between the surface of the SiO ₂ airgel powder to be treated and water, the test result is 31°, and then place the SiO ₂ airgel powder with a particle size of 0.2mm in a vacuum In the heating furnace, use a container to place the weighed trimethylchlorosilane in a vacuum heating furnace, heat and gasify, and perform hydrophobic modification for 1.5 hours to obtain hydrophobic _SiO2 airgel powder, and use a contact angle meter to detect the hydrophobicity. The contact angle between the surface of SiO ₂ airgel powder and water is 150°;

(2) At room temperature, weigh sodium fatty alcohol polyoxyethylene ether sulfate, sodium alkylbenzene sulfonate, isopropanol and deionized water according to the mass ratio of 1:1:0.8:200, mix them evenly, and make the surface hydrophilic modified solution;

(3) According to the volume ratio of hydrophobic SiO ₂ airgel powder and surface hydrophilic modification solution 1:3, weigh the surface modification solution, and pour it into the corresponding container, and put the hydrophobic SiO ₂ after step (1) The airgel powder is mixed with the surface hydrophilic modification solution, and after mechanical stirring for 15 minutes, the rotating speed is 2500 rpm, and then filtered;

(4) Place the SiO ₂ airgel powder with hydrophilic modification solution on the surface obtained in step (3) in a far-infrared drying oven, dry at 120°C for 0.5h, and cool down to below 50°C with the furnace After taking it out, the cross-section of the _SiO2 airgel powder is detected, and the detection results show that the thickness of the surface hydrophilic layer is 11.1 μm;

(5) Weigh the SiO ₂ airgel, one-component water-based epoxy resin and deionized water in step (4) according to the mass ratio of 1:30:100, stir and mix to obtain the SiO ₂ airgel composite slurry;

(6) Set the ultrasonic vibration frequency to 3 GHz, open the valve, so that the SiO ₂ airgel composite slurry flows to the ultrasonic vibration table, and atomize the SiO ₂ airgel composite slurry to obtain an atomized body. During the falling process, it is treated with far-infrared radiation and cured to obtain enhanced SiO ₂ airgel powder, and the thickness of the epoxy resin coating layer is 13-15 μm.

Example 5

The following steps are used to prepare reinforced SiO ₂ airgel powder with internal hydrophobicity, surface hydrophilicity, and surface coating of water-based silicone resin film. The thickness of the silicone resin coating layer is 8-10 μm:

(1) Use a contact angle measuring instrument to detect the contact angle between the surface of the SiO ₂ airgel powder with a particle size of 77 μm and water. If the test result is 140°, the SiO ₂ airgel powder is hydrophobic;

(2) At room temperature, weigh sodium lauryl sulfate, acetone and deionized water at a mass ratio of 1:0.6:150, mix them evenly, and prepare a surface hydrophilic modification solution;

(3) According to the volume ratio of hydrophobic SiO ₂ airgel powder and surface hydrophilic modification solution 1:3, weigh the surface modification solution, and pour it into the corresponding container, and put the hydrophobic SiO ₂ after step (1) The airgel powder is mixed with the surface hydrophilic modification solution, and after ball milling for 25 minutes, it is taken out and filtered;

(4) Place the SiO ₂ airgel powder with hydrophilic modification solution on the surface obtained in step (3) in a blast drying oven, dry at 120°C for 0.5h, and cool down to below 50°C with the furnace After taking it out, the cross-section of the _SiO2 airgel powder is detected, and the detection results show that the thickness of the surface hydrophilic layer is 6.9 μm;

(5) Weigh the SiO ₂ airgel, water-based silicone resin and deionized water in step (4) according to the mass ratio of 1:35:100, stir and mix to obtain the SiO ₂ airgel composite slurry;

(6) Set the ultrasonic vibration frequency to 2 GHz, open the valve, so that the SiO ₂ airgel composite slurry flows to the ultrasonic vibration table, and atomize the SiO ₂ airgel composite slurry to obtain an atomized body. During the falling process, it is treated with far-infrared radiation and cured to obtain enhanced SiO ₂ airgel powder, and the thickness of the silicone resin coating layer is 8-10 μm.

Example 6

The following steps were used to prepare reinforced _SiO2 airgel powders with internal hydrophobicity, surface hydrophilicity, and surface coating with acrylic film, and the thickness of the acrylic coating layer was 9-12 μm:

(1) Use a contact angle measuring instrument to detect the contact angle between the surface of the SiO ₂ airgel powder with a particle size of 75 μm and water. If the test result is 141°, the SiO ₂ airgel powder is hydrophobic;

(2) At room temperature, weigh nonylphenol polyoxyethylene ether, n-hexane and deionized water according to the mass ratio of 1:0.3:100, mix them evenly, and prepare a surface hydrophilic modification solution;

(3) According to the volume ratio of hydrophobic SiO ₂ airgel powder and surface hydrophilic modification solution 1:3, weigh the surface modification solution, and pour it into the corresponding container, and put the hydrophobic SiO ₂ after step (1) The airgel powder is mixed with the surface hydrophilic modification solution, and after ball milling for 15 minutes, it is taken out and filtered;

(4) Place the SiO ₂ airgel powder with hydrophilic modification solution on the surface obtained in step (3) in a far-infrared drying oven, dry at 120°C for 0.5h, and cool down to below 50°C with the furnace After taking it out, the cross-section of the _SiO2 airgel powder is detected, and the detection results show that the thickness of the surface hydrophilic layer is 11.1 μm;

(5) Weigh the SiO ₂ airgel, water-based acrylic resin and deionized water in step (4) according to the mass ratio of 1:40:100, stir and mix to obtain the SiO ₂ airgel composite slurry;

(6) Set the ultrasonic vibration frequency to 2 GHz, open the valve, so that the SiO ₂ airgel composite slurry flows to the ultrasonic vibration table, and atomize the SiO ₂ airgel composite slurry to obtain an atomized body. During the falling process, it is treated with far-infrared radiation and cured to obtain enhanced SiO ₂ airgel powder, and the thickness of the acrylic coating layer is 9-12 μm.

Example 7

The following steps were used to prepare reinforced TiO ₂ airgel powder with internal hydrophobicity, surface hydrophilicity, and surface coating of epoxy resin film. The thickness of the epoxy resin coating layer was 13-15 μm:

(1) Use a contact angle measuring instrument to detect the contact angle between the surface of the TiO ₂ airgel powder to be treated and water. If the test result is 145°, the TiO ₂ airgel powder is hydrophobic;

(2) At room temperature, weigh sodium alkylbenzenesulfonate, n-hexane and deionized water at a mass ratio of 1:0.8:120, mix them evenly, and prepare a surface hydrophilic modification solution;

(3) According to the volume ratio of hydrophobic TiO ₂ airgel powder and surface hydrophilic modification solution 1:3, weigh the surface modification solution, and pour it into the corresponding container, and put the hydrophobic TiO ₂ after step (1) The airgel powder is mixed with the surface hydrophilic modification solution, and after mechanical stirring for 15 minutes, the rotating speed is 2000 rpm, and then filtered;

(4) Place the TiO ₂ airgel powder with hydrophilic modification solution on the surface obtained in step (3) in a blast drying oven, dry at 120°C for 0.5h, and cool down to below 50°C with the furnace After taking it out, the cross-section of the _TiO2 airgel powder is detected, and the detection results show that the thickness of the surface hydrophilic layer is 6.0 μm;

(5) Weigh the TiO ₂ airgel, water-based epoxy resin and deionized water in step (4) according to the mass ratio of 1:40:100, stir and mix to obtain the TiO ₂ airgel composite slurry;

(6) Set the ultrasonic vibration frequency to 2 GHz, open the valve, so that the TiO ₂ airgel composite slurry flows to the ultrasonic vibration table, and atomize the TiO ₂ airgel composite slurry to obtain an atomized body. During the falling process, it is treated with far-infrared radiation and cured to obtain enhanced TiO ₂ airgel powder, and the thickness of the epoxy resin coating layer is 13-15 μm.

Example 8

The following steps were used to prepare reinforced _SiO2 airgel powders with internal hydrophobicity, surface hydrophilicity, and surface coating with acrylic film, and the thickness of the acrylic coating layer was 9-13 μm:

(1) Use a contact angle measuring instrument to detect the contact angle between the surface of the SiO ₂ airgel powder with a particle size of 0.3 mm and water. If the test result is 148°, the SiO ₂ airgel powder is hydrophobic ;

(2) At room temperature, weigh fatty alcohol polyoxyethylene ether ammonium sulfate, n-hexane, ethanol and deionized water according to the mass ratio of 1:0.4:0.3:130, mix them evenly, and prepare a surface hydrophilic modification solution;

(3) According to the volume ratio of hydrophobic SiO ₂ airgel powder and surface hydrophilic modification solution 1:3, weigh the surface modification solution, and pour it into the corresponding container, and put the hydrophobic SiO ₂ after step (1) The airgel powder is mixed with the surface hydrophilic modification solution, and after mechanical stirring for 15 minutes, the rotating speed is 2500 rpm, and then filtered;

(4) Place the SiO ₂ airgel powder with hydrophilic modification solution on the surface obtained in step (3) in a far-infrared drying oven, dry at 120°C for 0.5h, and cool down to below 50°C with the furnace After taking it out, the cross-section of the _SiO2 airgel powder is detected, and the detection results show that the thickness of the surface hydrophilic layer is 11.1 μm;

(5) Weigh the SiO ₂ airgel, water-based acrylic resin and deionized water in step (4) according to the mass ratio of 1:40:100, stir and mix to obtain the SiO ₂ airgel composite slurry;

(6) Set the ultrasonic vibration frequency to 2.5 GHz, open the valve, so that the SiO ₂ airgel composite slurry flows to the ultrasonic vibration table, and atomize the SiO ₂ airgel composite slurry to obtain an atomized body. During the falling process of the body, it is subjected to microwave heating treatment and solidified to obtain an enhanced SiO ₂ airgel powder, and the thickness of the acrylic coating layer is 9-13 μm.

The above-mentioned embodiment is a preferred embodiment of the present invention, but the embodiment of the present invention is not limited by the above-mentioned embodiment, and any other changes, modifications, substitutions, combinations, Simplifications should be equivalent replacement methods, and all are included in the protection scope of the present invention.

Claims (10)

1. An enhanced airgel powder, characterized in that the enhanced airgel powder is made of airgel powder and a coating material. 2. The enhanced airgel powder according to claim 1, wherein the coating material is a water-based adhesive. 3. a kind of enhanced airgel powder according to claim 2, is characterized in that, described aqueous adhesive is one or more in organic adhesive, inorganic adhesive; Described organic adhesive is rosin resin, alkyd Resin, acrylic resin, polyurethane resin, silicone resin, fluorocarbon resin, polyethylene resin, polystyrene resin, polyvinyl chloride resin, polypropylene resin, acrylonitrile-butadiene-styrene resin, etc. or Various; the inorganic adhesive is one or more of cement, gypsum, limestone, water glass, copper oxide-phosphoric acid glue, and the like. 4. A method for preparing an enhanced airgel powder, comprising the following steps: (1) Airgel powder modification; (2) Preparation of airgel composite slurry; (3) Continuously flow the airgel composite slurry to the ultrasonic atomizing head, so that the airgel composite slurry is dispersed into an atomized body of airgel powder coated with water-based adhesive; (4) Curing treatment. 5. The method for preparing a reinforced airgel powder according to claim 4, wherein the step (1) includes a hydrophobic modification step; The airgel powder is hydrophobically modified in an agent gas phase environment; the hydrophobic modifier is trimethylchlorosilane, hexamethyldisilazane, hexamethyldisiloxane, methyltrimethoxysilane , Methyltriethoxysilane, Dimethyldimethoxysilane, Dimethyldiethoxysilane, γ-Aminopropyltrimethoxysilane, γ-Aminopropyltriethoxysilane, γ- (2,3-Glycidoxy)propyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltriethoxy One or more of the base silanes. 6. A method for preparing an enhanced airgel powder according to claim 4, characterized in that, said step (1) also includes a surface hydrophilic modification step; said surface hydrophilic modification step is to use The surface hydrophilic modification solution modifies the surface layer of the hydrophobic airgel powder; the surface hydrophilic modification solution is an aqueous solution of a surfactant and a low surface tension solvent or an aqueous solution of a low surface tension solvent; the surfactant It is one or more of anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants; the anionic surfactants are fatty alcohol phosphate ester salts, fatty alcohol polyoxygen Vinyl ether phosphate, alkyl sulfate, fatty alcohol polyoxyethylene ether sulfate, glycerin fatty acid ester sulfate, sulfated ricinoleate, naphthene sulfate, fatty amide alkyl sulfate, alkylbenzenesulfonate One or more of acid salts, alkyl sulfonates, fatty acid methyl ester ethoxylate sulfonates, fatty acid methyl ester sulfonates, fatty alcohol polyoxyethylene ether carboxylates; the cationic surface active The agent is aliphatic ammonium salt; the amphoteric surfactant is one or more of alkyl amino acids, carboxylate betaines, sultaines, phosphate betaines, and alkyl oxyamines; the non- Ionic surfactants are aliphatic polyesters, alkylphenol polyoxyethylene ethers, high-carbon fatty alcohol polyoxyethylene ethers, fatty acid polyoxyethylene esters, fatty acid methyl ester ethoxylates, and ethylene oxide addition of polypropylene glycol One or more in substance, sorbitan ester, sucrose fatty acid ester, alkyl ester amide; Described low surface tension solvent is acetone, n-hexane, n-pentane, n-heptane, ethanol, isopropanol , tert-butanol, propylene glycol, glycerin in one or more mixtures. 7. The preparation method of a kind of enhanced airgel powder according to claim 6, is characterized in that, in the described surface hydrophilic modification step, also comprises the step of adding physical field action; The step of adding physical field action It is one of far-infrared radiation, stirring, ultrasonic treatment, and ball milling. 8. A method for preparing an enhanced airgel powder according to claim 4, wherein the step (1) further includes a drying step; the drying step is far-infrared drying, spray drying, One of microwave drying, normal pressure drying, supercritical drying, subcritical drying, and freeze drying. 9. A method for preparing an enhanced airgel powder according to claim 4, wherein the airgel composite slurry is prepared by modifying the airgel powder in step (1), Water-based adhesive and water are mixed and stirred. 10. The preparation method of a kind of enhanced airgel powder according to claim 4, characterized in that, the curing treatment is far-infrared radiation heating, microwave heating, ultraviolet radiation, natural curing, steam curing, autoclaving curing one or more of.