CN113122190A - Aerogel composite material and preparation method thereof - Google Patents
Aerogel composite material and preparation method thereof Download PDFInfo
- Publication number
- CN113122190A CN113122190A CN202110314561.9A CN202110314561A CN113122190A CN 113122190 A CN113122190 A CN 113122190A CN 202110314561 A CN202110314561 A CN 202110314561A CN 113122190 A CN113122190 A CN 113122190A
- Authority
- CN
- China
- Prior art keywords
- aerogel
- aerogel composite
- solution
- graphene oxide
- composite
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K5/00—Heat-transfer, heat-exchange or heat-storage materials, e.g. refrigerants; Materials for the production of heat or cold by chemical reactions other than by combustion
- C09K5/08—Materials not undergoing a change of physical state when used
- C09K5/14—Solid materials, e.g. powdery or granular
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J13/00—Colloid chemistry, e.g. the production of colloidal materials or their solutions, not otherwise provided for; Making microcapsules or microballoons
- B01J13/0091—Preparation of aerogels, e.g. xerogels
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/15—Nano-sized carbon materials
- C01B32/182—Graphene
- C01B32/198—Graphene oxide
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/113—Silicon oxides; Hydrates thereof
- C01B33/12—Silica; Hydrates thereof, e.g. lepidoic silicic acid
- C01B33/14—Colloidal silica, e.g. dispersions, gels, sols
- C01B33/157—After-treatment of gels
- C01B33/158—Purification; Drying; Dehydrating
- C01B33/1585—Dehydration into aerogels
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Dispersion Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Inorganic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Nanotechnology (AREA)
- Physics & Mathematics (AREA)
- Combustion & Propulsion (AREA)
- Thermal Sciences (AREA)
- Silicon Compounds (AREA)
Abstract
The invention relates to an aerogel composite material and a preparation method thereof, wherein the preparation method comprises the following steps: the structure comprises a three-dimensional network structure skeleton formed by silica sol crosslinking, silver nanoparticles and graphene nanosheets dispersed in the skeleton, wherein the graphene nanosheets are in covalent connection with the skeleton, the graphene nanosheets are connected with one another through the skeleton, and the silver nanoparticles are distributed on the skeleton and the graphene nanosheets. The aerogel composite material based on the invention has excellent photo-thermal conversion performance and mechanical property.
Description
Technical Field
The invention belongs to the field of aerogel composite material preparation, and particularly relates to an aerogel composite material and a preparation method thereof.
Background
Nowadays, with the rapid growth of global population and the increasing severity of water pollution problem, the shortage of fresh water resources has become one of the global problems facing human society, and the conversion of solar energy into heat energy for desalinating seawater by using photo-thermal materials is considered as an effective solution to the shortage of fresh water resources. The photo-thermal material is a functional material for converting sunlight into heat energy by utilizing the photo-thermal conversion mechanism of the material, and has wide application prospects in the fields of seawater desalination, sewage treatment and the like. In recent years, researchers have proposed a solar interface steam generating system capable of evaporating water on a liquid-gas interface, which system can produce clean water by using solar energy in an environment-friendly and efficient manner. In solar interfacial steam generation systems, the first strategy to maximize the use of solar energy is to develop photothermal materials with high light absorption throughout the solar spectrum to capture as much solar energy as possible. The photo-thermal material should satisfy the conditions of floating on the water surface, effectively absorbing sunlight and converting the sunlight into heat energy, having a hydrophilic structure and timely transporting water to an interface, etc. Therefore, the photothermal conversion material with high performance, environmental friendliness, high photothermal stability and high repeated practicability is researched and developed, and the high economic benefit and the high social benefit are achieved.
Graphene Oxide (GO) has a two-dimensional sheet structure, a large specific surface area, low thermal conductivity, extremely high light absorption rate in a full spectrum range, rich oxygen-containing functional groups such as hydroxyl and carboxyl, and economical preparation cost, and the graphene oxide aerogel material becomes an excellent candidate material for a photothermal conversion layer. However, when the graphene oxide aerogel material is immersed in an aqueous solution, the negatively charged graphene oxide sheets can be separated from each other under the action of electrostatic repulsion due to the presence of oxygen functional groups, resulting in severe damage to the GO aerogel material, which can delaminate and be damaged within a few hours, which limits the use of graphene oxide as a photo-thermal layer material. Therefore, improving the structural stability and prolonging the service life of the graphene oxide aerogel material is an urgent problem to be solved for the application of the graphene oxide aerogel material in the field of interfacial water evaporation.
Disclosure of Invention
The technical problem solved by the invention is as follows: the aerogel composite material and the preparation method thereof are provided for solving the problems of poor structural stability and short service life of the graphene oxide aerogel material in the prior art.
The specific solution provided by the invention comprises the following steps:
the present invention provides an aerogel composite comprising: the structure comprises a three-dimensional network structure skeleton formed by silica sol crosslinking, silver nanoparticles and graphene nanosheets dispersed in the skeleton, wherein the graphene nanosheets are in covalent connection with the skeleton, the graphene nanosheets are connected with one another through the skeleton, and the silver nanoparticles are distributed on the skeleton and the graphene nanosheets.
Based on the technical scheme of the invention, the method has the following technical effects:
(1) between graphite oxide alkene (GO) piece and the silica framework through O-Si key-type connection, on the one hand, make between the GO piece cross-linking each other, pile up and connect the skeleton that forms and have certain intensity, on the other hand, above-mentioned covalent link can strengthen GO aerogel and SiO2The aerogel interface combination improves the mechanical property of the composite material, and moreover, the SiO2The precursor can be crosslinked to form a skeleton with certain strength to support each GO sheet, so that the structural stability and the service life of the GO aerogel material applied to the interfacial water evaporation field are remarkably improved.
(2) Because the Ag nano particles have local surface plasmon effect (LSPR), the light absorption can be effectively induced, and the Ag nano particles and SiO can be mixed2The Ag nano-particle surface plasmon polariton composite material is compounded with a GO sheet, and the high light absorption rate of the Ag nano-particle local surface plasmon effect is utilized, so that the photo-thermal conversion efficiency of the material is greatly improved, the composite material has high photo-thermal conversion performance, and meanwhile, the composite material has excellent antibacterial performance.
(3)SiO2The aerogel is SiO2The precursor is crosslinked to form a three-dimensional network structure, the three-dimensional network structure has the advantages of high porosity, high specific surface area and the like, the heat insulation performance is outstanding, the heat dissipation efficiency of the precursor as a photo-thermal material can be reduced, and the photo-thermal conversion performance of the material is improved2The aerogel has the advantages of good heat insulation, small density, good mechanical property, no toxicity, no pollution and the like, the Ag nano particles have high light absorption and antibacterial property, and the aerogel composite material obtained by compounding the Ag nano particles, the Ag nano particles and the Ag nano particles has excellent light-heat conversion performance and mechanical property and can be used for seawater desalination, sewage treatment and light treatmentThe method has great application potential in the fields of thermal power generation, photo-thermal energy storage and the like.
Further, the porosity of the aerogel composite material is more than or equal to 90 percent, and the specific surface area is 850-950m2(ii) in terms of/g. The composite material has high porosity, high specific surface area and outstanding thermal performance, and can reduce the heat dissipation efficiency of the composite material as a photo-thermal material.
The photo-thermal conversion material prepared by the preparation method disclosed by the invention has the porosity of more than 90% and the specific surface area of 850-950m2(g) when formed to a thickness of 5mm, under solar radiation (1 KW/m)2) The photothermal performance is shown as: the light absorption rate is 80-95.4%, and the water evaporation rate is 1.55-1.75 kgm-2h-1The photo-thermal conversion efficiency is 83-92.6%, and the method can be applied to the field of seawater desalination.
Further, the number of layers of the graphene oxide is 1 or 2, the sheet diameter of the graphene oxide is 0.2-10 mu m, and the specific surface area of the graphene oxide is 300-1000 m2/g。
The single-layer graphene has large specific surface area and low thermal conductivity, and the upper and lower surfaces of each single-layer graphene oxide sheet can be connected with the silica framework through O-Si bonds, so that the GO sheets are mutually crosslinked and stacked and connected through the silica framework, and a high-strength framework is further formed.
The invention also provides a preparation method of the aerogel composite material, which comprises the following steps:
1) dissolving a silicon source in a mixed solution of water and ethanol, adding an acid catalyst to adjust the pH of the solution to 2-4, hydrolyzing to obtain a silicon source hydrolysate, adding an alkali catalyst to adjust the pH to 6-8, and performing polycondensation to obtain silica sol, wherein the volume ratio of the silicon source to the water to the ethanol is 1: (3-5): (7-9);
2) fully mixing the silica sol and the graphene oxide sheet aqueous dispersion, and carrying out ultrasonic treatment for 30-60min to obtain a composite wet gel;
3) freezing and molding the composite wet gel obtained in the step 2), and then freeze-drying to remove water to obtain the graphene and silicon dioxide composite aerogel composite material;
4) mixing the graphene prepared in the step 3) with dioxideSilica aerogel in Ag+Soaking in solution, and adding reducing agent to reduce Ag+And then freeze-drying to remove water to obtain the silver nanoparticle-loaded aerogel composite material.
Hydrolyzing and polycondensing a silicon source to form a silicon dioxide precursor (namely silicon dioxide sol), then adding graphene oxide sheet dispersion liquid, and utilizing a large amount of oxygen-containing functional groups (carboxyl and hydroxyl) and SiO rich on the surface of the graphene oxide sheet2HO-Si-OH bonds on the precursor further generate in-situ crosslinking reaction to generate O-Si-O bonds to form a crosslinking structure, connection is established among graphene oxide sheet layers, the structural stability of the graphene oxide sheet is improved, and simultaneously SiO2The precursor is further crosslinked to form a three-dimensional network structure skeleton with certain strength, and the graphene and silicon dioxide composite aerogel (namely GO/SiO) is obtained through freezing molding and freeze drying treatment2Composite aerogel) which greatly improves the mechanical properties of the graphene oxide aerogel and solves the problem that the graphene oxide aerogel material is easy to collapse on the water surface due to hydrophilicity; mixing GO/SiO2Soaking the composite aerogel in Ag+In the solution of (1), finally, Ag is added with a reducing agent+Reducing to enable the Ag nano particles to be fully loaded on the graphene oxide nanosheets and the three-dimensional network structure skeleton (namely the Ag nano particles enter the three-dimensional structure formed by the silicon dioxide skeleton and each graphene oxide sheet), and preparing the Ag/GO/SiO2The aerogel composite material and the Ag nano particles have high light absorption rate, and can effectively improve GO/SiO2The light absorption properties of the composite aerogel; SiO 22The aerogel has good heat insulation performance, high porosity, large specific surface area and small density, and can be compounded with graphene oxide sheets to prepare the composite aerogel, thereby effectively reducing the heat loss of the whole device and improving the photothermal conversion efficiency of the material.
The preparation method of the aerogel composite material based on the invention has simple process, and prepares the aerogel composite material with good photo-thermal property and structural stability by fully utilizing the performance advantages of the three materials.
Specifically, graphene oxide sheets are dispersed in water by ultrasonic treatment to obtain the graphene oxide sheet aqueous dispersion.
Specifically, in the step 3), the composite wet gel is placed in a container containing liquid nitrogen for freezing and forming.
Further, the silicon source is sodium silicate, methyl orthosilicate or ethyl orthosilicate.
Further, the acid catalyst is hydrochloric acid solution, the concentration of the hydrochloric acid solution is 0.0005-0.005mol/L, the base catalyst is ammonia water solution, and the concentration of the ammonia water solution is 0.01-1 mol/L.
And (3) regulating the pH value of the mixed solution by adding a hydrochloric acid solution to hydrolyze the mixed solution, and adding an alkali solution to polycondensing the mixed solution.
Preferably, the solution is adjusted to pH 3 by the addition of an acid catalyst and to pH 7 by the addition of a base catalyst to effect polycondensation.
Further, the concentration of graphene oxide in the graphene oxide dispersion liquid is 1mg/mL, and the weight ratio of the silica sol to the graphene oxide dispersion liquid is (0.8-1.2): 1.
The composite material thus obtained has high strength, high porosity and large specific surface area.
Specifically, the silica sol and the graphene oxide aqueous dispersion are subjected to ultrasonic dispersion for 30-60min, and then magnetic stirring is performed for 30-60min, so that the silica sol and the graphene oxide sheets are fully mixed and crosslinked to obtain the composite wet gel.
Further, in the step 2) and the step 3), the temperature of freeze drying is-50 to-35 ℃, the vacuum degree is 10 to 15Pa, and the freeze drying time is 12 to 30 hours.
Specifically, before freeze-drying, a freeze-drying machine is pre-cooled to a required freeze-drying temperature, and then the graphene oxide and silicon dioxide composite aerogel is put into the freeze-drying machine.
The porosity and the specific surface area of the sample can be changed by changing the temperature and the vacuum degree of freeze drying, and the graphene and silicon dioxide composite aerogel material with high specific surface area and high porosity can be obtained by the freeze drying and the vacuum degree.
Further, the Ag+The solution is nitreSilver acid or silver acetate solution, said Ag+The mass fraction of the solution is 0.1-20%, and the soaking time is 10-30 min.
Under the above conditions, a certain Ag load can be ensured, the photo-thermal conversion performance is good, and the cost is low.
Therefore, the photothermal conversion performance of the composite material can be changed by regulating the loading capacity of the Ag nanoparticles and the temperature and the vacuum degree of freeze drying in the vacuum freeze drying process, the regulation and the control are convenient, the process practicability is strong, and the batch production is easy to realize.
Further, the Ag+The reducing agent is selected from one of glucose, glycol, formaldehyde, hydrazine hydrate or sodium borohydride, and is mixed with Ag+Ag in solution+The mass ratio of (a) to (b) is 1:1 to 2: 1.
Based on the aerogel composite material, graphene oxide sheets and SiO with high porosity and high specific surface area2The composite aerogel is obtained by compounding, and the heat insulation performance is good; the graphene oxide sheets are connected with the silicon dioxide through the O-Si bonds, the mechanical property of the composite material is improved, the structural stability and the service life of the composite material as a thermoelectric material are improved, the photothermal conversion performance of the composite material is improved by adding the Ag nanoparticles, the composite aerogel material suitable for the photothermal field is finally obtained, the photothermal conversion material is prepared from the composite material, the chemical stability, the high light absorption property and the low heat conductivity of the GO aerogel material can be fully utilized, and the SiO is fully utilized2The chemical corrosion resistance, high heat insulation property (high porosity and high specific surface area) and high mechanical property of the aerogel are achieved, and the light absorption property of the Ag nanoparticles is utilized to remarkably improve the structural stability and the photothermal conversion efficiency of the graphene membrane in the prior art.
Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Detailed Description
The following detailed description of embodiments of the invention is intended to be illustrative, and is not to be construed as limiting the invention.
The invention is illustrated with reference to specific examples.
Example 1
Preparing a precursor: tetraethoxysilane (TEOS) is used as a silicon source, is mixed with water and absolute ethyl alcohol (the volume ratio is 1: 4: 8), 0.001mol/L dilute hydrochloric acid solution is added to adjust the pH value of the mixed solution to be 3 and is stirred, 0.5mol/L ammonia water solution is added to be stirred to adjust the pH value of the mixed solution to be neutral, and SiO is obtained2And (3) an aerogel precursor.
According to the weight percentage, 100 parts of self-made silica sol and 100 parts of graphene oxide aqueous dispersion are mixed and ultrasonically dispersed for 30min, and then are magnetically stirred for 30min to be fully and uniformly mixed; transferring the mixed solution into a polytetrafluoroethylene mold (the inner diameter is 30mm, the depth is 5mm, the wall thickness is 5mm), placing the polytetrafluoroethylene mold in liquid nitrogen for freezing and forming, wherein the freezing time is 10min, then transferring the polytetrafluoroethylene mold into a vacuum freeze dryer, pre-cooling the polytetrafluoroethylene mold in the vacuum freeze dryer for 30min to-35 ℃, keeping the vacuum degree at 10Pa, and carrying out vacuum freeze drying for 24h to prepare GO/SiO2An aerogel; mixing GO/SiO2Soaking aerogel in 100 parts of 0.1% AgNO3Adding glucose into the solution for 10min, and adding silver nitrate to obtain Ag solution+Reducing the mixture into silver nanoparticles, and fully compounding the silver nanoparticles onto GO sheets and a three-dimensional network structure skeleton; finally, compounding GO/SiO with silver nano particles2Transferring the aerogel into a vacuum freeze dryer, pre-cooling the aerogel in the vacuum freeze dryer for 30min to-50 ℃, keeping the vacuum degree at 10Pa, and carrying out vacuum freeze drying for 24h to prepare GO/Ag/SiO2A composite aerogel composite.
Through tests, the porosity of the composite aerogel prepared in the embodiment is 97%, and the specific surface area is 950m2(ii) a light absorption of 95.4%, a water evaporation rate of 1.75kgm-2h-1And the photothermal conversion efficiency is 92.6%.
Example 2
Preparing a precursor: the precursor preparation was as in example 1.
According to the weight percentage, 100 parts of self-made silicon dioxide sol and 100 parts of graphene oxide aqueous dispersion are mixed and ultrasonically dispersed for 60min, and then the mixture is magnetically stirred for 60min to be filledUniformly mixing; transferring the mixed solution into a polytetrafluoroethylene mold (the inner diameter is 30mm, the depth is 5mm, the wall thickness is 5mm), placing the polytetrafluoroethylene mold in liquid nitrogen for freezing and forming, freezing for 30min, then transferring the polytetrafluoroethylene mold into a vacuum freeze dryer, pre-cooling for 30min to-50 ℃ by the vacuum freeze dryer, keeping the vacuum degree at 15Pa, and carrying out vacuum freeze drying for 24h to prepare GO/SiO2An aerogel; mixing GO/SiO2Soaking aerogel in 100 parts of 20% AgNO3Adding hydrazine hydrate in an amount equal to that of silver nitrate to dissolve Ag for 30min+Reducing the mixture into silver nanoparticles, and fully compounding the silver nanoparticles onto GO sheets and a three-dimensional network structure skeleton; finally, compounding GO/SiO with silver nano particles2Transferring the aerogel into a vacuum freeze dryer, pre-cooling the aerogel in the vacuum freeze dryer for 30min to-35 ℃, keeping the vacuum degree at 15Pa, and carrying out vacuum freeze drying for 24h to prepare GO/Ag/SiO2A composite aerogel composite.
Through tests, the porosity of the composite aerogel prepared in the embodiment is 90%, and the specific surface area is 850m2(iv) g, light absorption 80%, water evaporation rate 1.55kgm-2h-1And the photothermal conversion efficiency was 83%.
Example 3
Preparing a precursor: the same as in example 1.
According to the weight percentage, 100 parts of self-made silica sol and 100 parts of graphene oxide aqueous dispersion are mixed and ultrasonically dispersed for 40min, and then are magnetically stirred for 40min to be fully and uniformly mixed; transferring the mixed solution into a polytetrafluoroethylene mold (the inner diameter is 30mm, the depth is 5mm, the wall thickness is 5mm), placing the polytetrafluoroethylene mold in liquid nitrogen for freezing and forming, freezing for 15min, then transferring the polytetrafluoroethylene mold into a vacuum freeze dryer, pre-cooling the polytetrafluoroethylene mold in the vacuum freeze dryer for 30min to-40 ℃, keeping the vacuum degree at 12Pa, and carrying out vacuum freeze drying for 24h to prepare GO/SiO2An aerogel; mixing GO/SiO2Soaking aerogel in 100 parts of 10% silver acetate solution for 15min, and adding sodium borohydride in an amount of 2 times that of silver acetate to obtain Ag+Reducing the mixture into silver nanoparticles, and fully compounding the silver nanoparticles onto GO sheets and a three-dimensional network structure skeleton; finally, compounding GO/SiO with silver nano particles2Transferring the aerogel to a vacuum freeze dryerPre-cooling with an air freeze dryer for 30min to-40 deg.C, vacuum degree of 12Pa, vacuum freeze drying for 24h to obtain GO/Ag/SiO2A composite aerogel composite.
Through tests, the porosity of the composite aerogel prepared in the embodiment is 92%, and the specific surface area is 887m2(ii) a light absorption of 90%, a water evaporation rate of 1.60kgm-2h-1And the photothermal conversion efficiency is 85%.
Example 4
Preparing a precursor: the same as in example 1.
According to the weight percentage, 100 parts of self-made silica sol and 100 parts of graphene oxide aqueous dispersion are mixed and ultrasonically dispersed for 50min, and then are magnetically stirred for 50min to be fully and uniformly mixed; transferring the mixed solution into a polytetrafluoroethylene mold (the inner diameter is 30mm, the depth is 5mm, the wall thickness is 5mm), placing the polytetrafluoroethylene mold in liquid nitrogen for freezing and forming, freezing for 20min, then transferring the polytetrafluoroethylene mold into a vacuum freeze dryer, pre-cooling the polytetrafluoroethylene mold in the vacuum freeze dryer for 30min to-45 ℃, keeping the vacuum degree at 13Pa, and carrying out vacuum freeze drying for 24h to prepare GO/SiO2An aerogel; mixing GO/SiO2Soaking aerogel in 100 parts of 5% AgNO3Adding formaldehyde in an amount equal to that of silver nitrate to dissolve Ag for 20min+Reducing the mixture into silver nanoparticles, and fully compounding the silver nanoparticles onto GO sheets and a three-dimensional network structure skeleton; finally, compounding GO/SiO with silver nano particles2Transferring the aerogel into a vacuum freeze dryer, pre-cooling the aerogel in the vacuum freeze dryer for 30min to-45 ℃, keeping the vacuum degree at 13Pa, and carrying out vacuum freeze drying for 24h to prepare GO/Ag/SiO2A composite aerogel composite.
Through tests, the porosity of the composite aerogel prepared in the embodiment is 95%, and the specific surface area is 923m2(ii) a light absorption of 92.6%, a water evaporation rate of 1.68kgm-2h-1And the photothermal conversion efficiency was 89%.
Comparative example 1
According to the weight percentage, 100 parts of graphene oxide aqueous dispersion are taken to be mixed and ultrasonically dispersed for 60min, and then the mixture is magnetically stirred for 60min to be fully and uniformly mixed; and transferring the mixed solution into a polytetrafluoroethylene mold (the inner diameter is 30mm, the depth is 5mm, and the wall thickness is 5mm), placing the polytetrafluoroethylene mold into liquid nitrogen for freezing and forming, wherein the freezing time is 30min, then transferring the polytetrafluoroethylene mold into a vacuum freeze dryer, precooling the polytetrafluoroethylene mold into the vacuum freeze dryer for 30min to-50 ℃, and carrying out vacuum freeze drying for 24h to prepare the GO aerogel, wherein the vacuum degree is 15 Pa.
GO/Ag/SiO prepared for examples 1-42The composite aerogel and the GO aerogel prepared in the comparative example 1 were placed in beakers filled with water, and the structure was observed to collapse after 60 seconds of GO aerogel and was completely dispersed in water, while GO/Ag/SiO2The composite aerogel has a stable structure on the water surface and is not dispersed in the water, and the GO/Ag/SiO obtained based on the method2The composite aerogel has good structural stability and service life in water, high light absorption rate and high photo-thermal conversion efficiency, and can be used as a photo-thermal conversion material to be applied to the field of solar-driven interfacial water evaporation.
Although embodiments of the present invention have been described in detail above, those of ordinary skill in the art will understand that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.
Claims (10)
1. An aerogel composite, comprising: the structure comprises a three-dimensional network structure skeleton formed by silica sol crosslinking, silver nanoparticles and graphene nanosheets dispersed in the skeleton, wherein the graphene nanosheets are in covalent connection with the skeleton, the graphene nanosheets are connected with one another through the skeleton, and the silver nanoparticles are distributed on the skeleton and the graphene nanosheets.
2. The aerogel composite of claim 1, wherein the aerogel composite has a porosity of 90% or more and a specific surface area of 850-2/g。
3. The aerogel composite of claim 1, wherein the number of graphene oxide layers is 1 or 2, and the flake diameter of graphene oxide is 0.2 to ℃10 mu m, and the specific surface area of the graphene oxide is 300-1000 m2/g。
4. A method of preparing an aerogel composite as claimed in any of claims 1 to 3, comprising the steps of:
1) dissolving a silicon source in a mixed solution of water and ethanol, adding an acid catalyst to adjust the pH of the solution to 2-4, hydrolyzing to obtain a silicon source hydrolysate, adding an alkali catalyst to adjust the pH to 6-8, and performing polycondensation to obtain silica sol, wherein the volume ratio of the silicon source to the water to the ethanol is 1: (3-5): (7-9);
2) fully mixing the silica sol and the graphene oxide sheet aqueous dispersion, and carrying out ultrasonic treatment for 30-60min to obtain a composite wet gel;
3) freezing and molding the composite wet gel obtained in the step 2), and then freeze-drying to remove water to obtain the graphene and silicon dioxide composite aerogel composite material;
4) applying the graphene and silicon dioxide aerogel prepared in the step 3) to Ag+Soaking in solution, and adding reducing agent to reduce Ag+And then freeze-drying to remove water to obtain the silver nanoparticle-loaded aerogel composite material.
5. The method of preparing an aerogel composite of claim 4, wherein the silicon source is sodium silicate water glass, methyl orthosilicate, or ethyl orthosilicate.
6. The method of preparing an aerogel composite of claim 4, wherein the acid catalyst is a hydrochloric acid solution having a concentration of 0.0005 to 0.005mol/L, the base catalyst is an aqueous ammonia solution having a concentration of 0.01 to 1 mol/L.
7. The method for preparing an aerogel composite according to claim 4, wherein the concentration of graphene oxide in the graphene oxide dispersion liquid is 1mg/mL, and the weight ratio of the silica sol to the graphene oxide dispersion liquid is (0.8-1.2): 1.
8. The preparation method of the aerogel composite material as claimed in claim 4, wherein the freeze-drying temperature in step 3) and the freeze-drying temperature in step 4) are respectively-50 to-35 ℃, the vacuum degree is respectively 10 to 15Pa, and the freeze-drying time is respectively 12 to 30 hours.
9. The method of preparing an aerogel composite of claim 4, further wherein the Ag is+The solution is silver nitrate or silver acetate solution, and the Ag is+The mass fraction of the solution is 0.1-20%, and the soaking time is 10-30 min.
10. Method for the preparation of aerogel composites according to claim 4, characterized in that the Ag is+The reducing agent is selected from one of glucose, glycol, formaldehyde, hydrazine hydrate or sodium borohydride, and is mixed with Ag+Ag in solution+The mass ratio of (a) to (b) is 1:1 to 2: 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110314561.9A CN113122190A (en) | 2021-03-24 | 2021-03-24 | Aerogel composite material and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110314561.9A CN113122190A (en) | 2021-03-24 | 2021-03-24 | Aerogel composite material and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113122190A true CN113122190A (en) | 2021-07-16 |
Family
ID=76774187
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110314561.9A Pending CN113122190A (en) | 2021-03-24 | 2021-03-24 | Aerogel composite material and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113122190A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114250046A (en) * | 2022-01-07 | 2022-03-29 | 科顺防水科技股份有限公司 | Butyl pressure-sensitive adhesive and preparation method and application thereof |
| CN115998944A (en) * | 2022-12-29 | 2023-04-25 | 武汉市第三医院 | Nano-silver functionalized antibacterial material and preparation method and application thereof |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104587918A (en) * | 2015-01-30 | 2015-05-06 | 河海大学 | Silver nano-particle modified carbon ball/graphene composite aero-gel material as well as preparation method and application of material |
| CN106912499A (en) * | 2017-03-16 | 2017-07-04 | 中国科学院城市环境研究所 | A kind of sterilized composite and preparation method thereof |
| CN107235744A (en) * | 2017-06-02 | 2017-10-10 | 东南大学 | A kind of preparation method of graphene aerosil |
| CN109915728A (en) * | 2018-12-24 | 2019-06-21 | 国网浙江龙游县供电有限公司 | A kind of SF6Full-automatic vacuum-pumping inflates cart |
-
2021
- 2021-03-24 CN CN202110314561.9A patent/CN113122190A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104587918A (en) * | 2015-01-30 | 2015-05-06 | 河海大学 | Silver nano-particle modified carbon ball/graphene composite aero-gel material as well as preparation method and application of material |
| CN106912499A (en) * | 2017-03-16 | 2017-07-04 | 中国科学院城市环境研究所 | A kind of sterilized composite and preparation method thereof |
| CN107235744A (en) * | 2017-06-02 | 2017-10-10 | 东南大学 | A kind of preparation method of graphene aerosil |
| CN109915728A (en) * | 2018-12-24 | 2019-06-21 | 国网浙江龙游县供电有限公司 | A kind of SF6Full-automatic vacuum-pumping inflates cart |
Non-Patent Citations (2)
| Title |
|---|
| 任洪波等: "《气凝胶手册》", 31 December 2014, 中国原子能出版社 * |
| 施德辉: "二氧化硅/氧化石墨烯复合气凝胶的制备及其吸附性能与电化学性能的研究", 《中国优秀博硕士学位论文全文数据库（硕士） 工程科技I辑》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114250046A (en) * | 2022-01-07 | 2022-03-29 | 科顺防水科技股份有限公司 | Butyl pressure-sensitive adhesive and preparation method and application thereof |
| CN115998944A (en) * | 2022-12-29 | 2023-04-25 | 武汉市第三医院 | Nano-silver functionalized antibacterial material and preparation method and application thereof |
| CN115998944B (en) * | 2022-12-29 | 2024-05-07 | 武汉市第三医院 | Nano-silver functionalized antibacterial material and preparation method and application thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109096504B (en) | Gradient gel, preparation method and application thereof | |
| CN113603935B (en) | Composite aerogel with Janus characteristics and preparation method and application thereof | |
| CN101372337B (en) | Method for preparing transparent silicon dioxide aerogel by co-precursor normal atmosphere drying | |
| Chen et al. | MXene-doped kapok fiber aerogels with oleophobicity for efficient interfacial solar steam generation | |
| CN114405421B (en) | Cellulose nanofiber aerogel photothermal interface water evaporation material and preparation method thereof | |
| CN109603596B (en) | Photo-thermal seawater desalination membrane made of metal organic framework material | |
| CN113122190A (en) | Aerogel composite material and preparation method thereof | |
| CN101774592A (en) | High heat insulation transparent SiO2 aerogel film material and preparation method thereof | |
| Xu et al. | A carbonized carbon dot-modified starch aerogel for efficient solar-powered water evaporation | |
| CN112108084A (en) | Preparation method of hydrogel with hierarchical pore structure for accelerating solar water evaporation | |
| Guo et al. | Double-layered montmorillonite/MoS2 aerogel with vertical channel for efficient and stable solar interfacial desalination | |
| CN111186830A (en) | Hollow carbon sphere photo-thermal material and preparation method thereof | |
| WO2022166345A1 (en) | Large-scale preparation method for three-dimensional porous nano composite cooling thin film | |
| CN115491020A (en) | Janus type composite foam photo-thermal functional material and preparation method and application thereof | |
| Cui et al. | Large-scale fabrication of expanded graphite aerogel-based phase change material composite for efficient solar harvesting | |
| Shen et al. | Recent progress and applications of aerogels in China | |
| Gao et al. | A simple and controllable black hydrogel coating strategy to prepare self-cleaning and durable evaporator for efficient solar steam generation | |
| CN113024884B (en) | Composite quaternary hydrogel capable of realizing high solar evaporation rate and preparation method thereof | |
| CN116216824B (en) | Hydrogel type interface photo-thermal evaporator and preparation and application methods thereof | |
| CN112341738A (en) | 3D self-floating heat-insulation efficient photo-thermal steam conversion material and preparation method thereof | |
| CN111807336B (en) | Amorphous molybdenum oxide nanodot/two-dimensional carbon nitride nanosheet with photocatalysis and photothermal conversion performances and preparation method thereof | |
| CN116948336A (en) | MXene-based photo-thermal composite foam material, and preparation method and application thereof | |
| Jin et al. | Chitosan/multilayered MXene Nanocomposites Loaded in 3D Nitrogen‐Doped Carbon Networks for Seawater Desalination with Highly Efficient Photothermal Conversion | |
| Zhang et al. | Preparation of three-dimensional graphene-based sponge as photo-thermal conversion material to desalinate seawater | |
| CN109320195B (en) | Al2O3-SiO2Method for preparing composite material |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20210716 |