Sunlight dynamic regulation transparent heat-insulation aerogel film and preparation method and application thereof

Abstract

The invention provides a sunlight dynamic regulation transparent heat-insulation aerogel film as well as a preparation method and application thereof, and belongs to the technical field of aerogel materials. The invention provides a sunlight dynamic regulation transparent heat-insulation aerogel film which comprises the following components in percentage by mass: 0.5-1.5% of phase change nanoparticles and 98.5-99.5% of silica aerogel, the phase change nanoparticles are distributed in the silica aerogel, and the silica aerogel is prepared from organic silane containing methyl. According to the invention, a hydrophobic skeleton is constructed by organosilane containing methyl, phase change nanoparticles are added into silica aerogel to form a three-dimensional nano network, and the phase change nanoparticles realize dynamic photo-thermal regulation by regulating and controlling the transmissivity of a sunlight wave band at a specific temperature; the obtained sunlight dynamic regulation and control transparent heat insulation aerogel film has self-adaptive photo-thermal regulation, high light transmittance and super heat insulation performance, and is suitable for the high-end fields of intelligent building curtain walls, spacecraft thermal control and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of aerogel materials, and in particular to a transparent thermal insulation aerogel film dynamically regulated by sunlight, and a preparation method and application thereof. Background Art

[0002] Aerogel is a lightweight nanoporous material with a basic structure of a three-dimensional nano-network skeleton. It has the characteristics of high specific surface area, high porosity, and low density, which gives aerogel materials unique properties such as low thermal conductivity, low dielectric constant, low refractive index, and high acoustic impedance. The pore size of aerogel materials (2-50nm) is smaller than the mean free path of air molecules (70nm), which can effectively suppress gas heat flow, making aerogel have extremely low thermal conductivity. The thermal conductivity at room temperature is only 0.013W / (m·K), which is the thermal insulation material with the best thermal insulation performance in atmospheric environment. However, aerogel has the following key problems in the field of light and heat regulation of smart windows: contradiction between light transmission and thermal insulation performance: aerogels in related technologies achieve low thermal conductivity through high porosity, but the visible light transmittance is generally less than 50%. High light transmittance materials have a thermal conductivity of >0.1W / (m·K) due to their dense structure, which makes it difficult to meet the needs of scenes such as building energy-saving windows that require both light transmission and thermal insulation. Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide a transparent thermal insulation aerogel film that can be dynamically regulated by sunlight, as well as its preparation method and application. The transparent thermal insulation aerogel film provided by the present invention has adaptive light and heat regulation, high light transmittance, and super thermal insulation properties.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] The invention provides a transparent thermal insulation aerogel film dynamically regulated by sunlight, comprising the following components in mass percentage: 0.5-1.5% of phase-change nanoparticles and 98.5-99.5% of silica aerogel, wherein the phase-change nanoparticles are distributed in the silica aerogel, and the silica aerogel is made of organic silane containing methyl.

[0006] Preferably, the organosilane includes methyltrimethoxysilane and / or methyltriethoxysilane.

[0007] Preferably, the phase-change nanoparticles include vanadium dioxide and / or tungsten trioxide.

[0008] Preferably, the particle size of the phase-change nanoparticles is 10 to 50 nm.

[0009] Preferably, the thickness of the sunlight dynamically regulated transparent thermal insulation aerogel film is 2 to 10 mm.

[0010] The present invention also provides a method for preparing a transparent thermal insulation aerogel film dynamically controlled by sunlight as described in the above technical solution, comprising the following steps:

[0011] dispersing the acidic solution and the organosilane to obtain a first dispersion;

[0012] dispersing the first dispersion, a surfactant, water, and phase-change nanoparticles to obtain a second dispersion;

[0013] The second dispersion is allowed to stand and then mixed with an alkaline solution to obtain an aerogel precursor dispersion, which is then gelled to obtain a gel;

[0014] The gel is dried to obtain the sunlight dynamically regulated transparent thermal insulation aerogel film.

[0015] Preferably, the acidic solution includes one or more of a hydrochloric acid solution, an acetic acid solution and a nitric acid solution.

[0016] Preferably, the surfactant includes one or more of polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer, hexadecyltrimethylammonium bromide and hexadecyltrimethylammonium chloride.

[0017] Preferably, the alkaline solution comprises one or more of aqueous ammonia, urea and tetramethylammonium hydroxide solution.

[0018] The present invention also provides the application of the sunlight-dynamically regulated transparent thermal insulation aerogel film described in the above technical solution or the sunlight-dynamically regulated transparent thermal insulation aerogel film prepared by the preparation method described in the above technical solution in the field of intelligent building curtain walls or spacecraft thermal control.

[0019] The invention provides a transparent thermal insulation aerogel film dynamically regulated by sunlight, comprising the following components in mass percentage: 0.5-1.5% of phase-change nanoparticles and 98.5-99.5% of silica aerogel, wherein the phase-change nanoparticles are distributed in the silica aerogel, and the silica aerogel is made of organic silane containing methyl.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention constructs a hydrophobic backbone using a methyl-containing organosilane. Phase-change nanoparticles are added to the silica aerogel to form a three-dimensional nanonetwork. The phase-change nanoparticles achieve dynamic photothermal regulation by regulating the transmittance of sunlight wavelengths at a specific temperature. The resulting sunlight-dynamically regulated transparent insulating aerogel film combines adaptive photothermal regulation, high light transmittance, and super-insulating properties, making it suitable for high-end applications such as intelligent building curtain walls and spacecraft thermal control. Furthermore, the methyl-containing organosilane in the present invention can reduce capillary forces that damage the pore structure of the hydrophobic backbone, making the sunlight-dynamically regulated transparent insulating aerogel film hydrophobic.

[0022] The present invention also provides a method for preparing the transparent thermal insulation aerogel film dynamically regulated by sunlight as described in the above technical solution. The preparation method of the present invention is simple to operate and easy to realize industrial application. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a scanning electron microscope image of the sunlight dynamically regulated transparent thermal insulation aerogel film prepared in Example 3;

[0024] Figure 2 This is a graph showing the hydrophobic contact angle of the transparent thermal insulation aerogel film dynamically regulated by sunlight obtained in Example 3;

[0025] Figure 3 The transmittance spectra of the transparent thermal insulation aerogel film dynamically regulated by sunlight prepared in Example 3 at different temperatures. DETAILED DESCRIPTION

[0026] The invention provides a transparent thermal insulation aerogel film dynamically regulated by sunlight, comprising the following components in mass percentage: 0.5-1.5% of phase-change nanoparticles and 98.5-99.5% of silica aerogel, wherein the phase-change nanoparticles are distributed in the silica aerogel, and the silica aerogel is made of organic silane containing methyl.

[0027] In the present invention, the mass percentage of phase change nanoparticles in the sunlight dynamically regulated transparent insulating aerogel film can be 0.5%, 0.7%, 1%, 1.2%, 1.3%, 1.4% or 1.5%.

[0028] In the present invention, the phase-change nanoparticles are evenly distributed in the silica aerogel without agglomeration.

[0029] In the present invention, the phase-change nanoparticles preferably include vanadium dioxide (VO2) and / or tungsten trioxide (WO3).

[0030] In the present invention, the particle size of the phase-change nanoparticles is preferably 10 to 50 nm, specifically 10, 20, 30, 40 or 50 nm.

[0031] In the present invention, the mass percentage of the silica aerogel in the sunlight dynamically regulated transparent thermal insulation aerogel film can be 98.5%, 98.6%, 98.7%, 98.8%, 99%, 99.3% or 99.5%.

[0032] In the present invention, the organosilane preferably includes methyltrimethoxysilane (MTMS) and / or methyltriethoxysilane.

[0033] In the present invention, the thickness of the sunlight dynamically regulated transparent thermal insulation aerogel film is preferably 2 to 10 mm, specifically 2, 3, 4, 5, 6, 7, 8, 9 or 10 mm.

[0034] In the present invention, the silica aerogel preferably has a structure shown in Formula I:

[0035] (polymethylsilsesquioxane).

[0036] The transparent thermal insulation aerogel film dynamically regulated by sunlight of the present invention has both high transparency and thermal insulation properties, which is derived from the nanoporous structure of the silicon aerogel skeleton and the uniform dispersion of phase-change nanoparticles. The phase-change nanoparticles achieve dynamic photothermal regulation by regulating the transmittance of the sunlight band at a specific temperature. At the same time, the transparent thermal insulation aerogel film dynamically regulated by sunlight of the present invention is hydrophobic due to the use of organic silane with methyl group (hydrophobic group).

[0037] The present invention also provides a method for preparing a transparent thermal insulation aerogel film dynamically controlled by sunlight as described in the above technical solution, comprising the following steps:

[0038] dispersing the acidic solution and the organosilane to obtain a first dispersion;

[0039] dispersing the first dispersion, a surfactant, water, and phase-change nanoparticles to obtain a second dispersion;

[0040] The second dispersion is allowed to stand and then mixed with an alkaline solution to obtain an aerogel precursor dispersion, which is then gelled to obtain a gel;

[0041] The gel is dried to obtain the sunlight dynamically regulated transparent thermal insulation aerogel film.

[0042] In the present invention, unless otherwise specified, the raw materials used are commercially available products in the art.

[0043] The present invention disperses the acidic solution and the organic silane to obtain a first dispersion.

[0044] In the present invention, the acidic solution preferably includes one or more of hydrochloric acid solution, acetic acid solution and nitric acid solution.

[0045] In the present invention, the type of the organosilane is preferably the same as that in the above embodiment, which will not be described in detail here.

[0046] In the present invention, the concentration of the acidic solution is preferably 5-10 mM, specifically 5, 6, 7, 8, 9 or 10 mM.

[0047] In the present invention, the volume ratio of the acidic solution to the organosilane is preferably 10 to 20:1, specifically 10:1, 15:1 or 20:1.

[0048] In the present invention, the dispersion is preferably carried out by stirring at room temperature.

[0049] After obtaining the first dispersion, the present invention disperses the first dispersion, a surfactant, water and phase-change nanoparticles to obtain a second dispersion.

[0050] In the present invention, the surfactant preferably includes one or more of polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer, hexadecyltrimethylammonium bromide and hexadecyltrimethylammonium chloride.

[0051] In the present invention, the ratio of the organosilane to the surfactant in the first dispersion is preferably 20 mL:4.4 g.

[0052] In the present invention, the volume ratio of the organosilane to water in the first dispersion is preferably 20:8, and the water is preferably deionized water.

[0053] In the present invention, the dosage ratio of the organosilane contained in the first dispersion to the phase-change nanoparticles is preferably 20 mL: 0.07-0.36 g, specifically 20 mL: 0.27 g, 20 mL: 0.29 g or 20 mL: 0.14 g.

[0054] In the present invention, the surfactant, water and phase-change nanoparticles are preferably dispersed, and the obtained dispersion is added to the first dispersion, followed by stirring and ultrasonic treatment to obtain the second dispersion.

[0055] After obtaining the second dispersion, the present invention allows the second dispersion to stand and then mixes it with an alkaline solution to obtain an aerogel precursor dispersion, which is then gelled to obtain a gel.

[0056] In the present invention, the standing temperature is preferably 0-5°C, specifically 0, 1, 2, 3, 4 or 5°C, and the time is preferably 30-40 min, specifically 30, 35 or 40 min. The purpose of the standing is to lower the temperature of the second dispersion and prevent premature gelation during the synthesis process.

[0057] In the present invention, the alkaline solution preferably includes one or more of ammonia water, urea and tetramethylammonium hydroxide solution.

[0058] In the present invention, the concentration of the alkaline solution is preferably 0.5-1M, specifically 0.5, 0.6, 0.7, 0.8, 0.9 or 1M.

[0059] In the present invention, the volume ratio of the organosilane to the alkaline solution in the first dispersion is preferably 20:6-12.

[0060] In the present invention, the aerogel precursor dispersion is preferably poured into a mold and then waited for gelation.

[0061] After obtaining the gel, the present invention dries the gel to obtain the sunlight dynamically regulated transparent thermal insulation aerogel film.

[0062] In the present invention, the drying is preferably supercritical drying, and the pressure of the supercritical drying is preferably 9-10 Pa, the temperature is preferably 35-40° C., and the time is preferably 2 h.

[0063] Before the drying, the present invention preferably performs solvent replacement on the gel.

[0064] In the present invention, the solvent used in the solvent replacement includes one or more of methanol, ethanol and acetone.

[0065] In the present invention, the number of solvent replacement is preferably 3 to 5 times.

[0066] The present invention also provides the application of the sunlight-dynamically regulated transparent thermal insulation aerogel film described in the above technical solution or the sunlight-dynamically regulated transparent thermal insulation aerogel film prepared by the preparation method described in the above technical solution in the field of intelligent building curtain walls or spacecraft thermal control.

[0067] The present invention has no particular limitation on the specific manner of the application, and any manner familiar to those skilled in the art may be used.

[0068] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions of the present invention. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0069] Example 1

[0070] A method for preparing a transparent thermal insulation aerogel film dynamically regulated by sunlight comprises the following steps:

[0071] S1: Weigh 20 mL of a 5 mM acidic solution (hydrochloric acid solution) and 20 mL of an organosilane (methyltrimethoxysilane), and stir at room temperature to obtain a first dispersion;

[0072] S2: 4.4 g of surfactant (cetyltrimethylammonium bromide), 8 mL of deionized water, and 0.29 g of phase change nanoparticles (vanadium dioxide, particle size 10 nm) were weighed and added to the first dispersion, stirred, and ultrasonicated to obtain a second dispersion;

[0073] S3: The second dispersion was allowed to stand at low temperature (0°C) for 30 min, and 12 mL of 0.5 M alkaline solution (urea solution) was added to obtain an aerogel precursor dispersion, which was poured into a 2 mm thick mold and waited for gelation.

[0074] S4: After the obtained gel was subjected to solvent (methanol) replacement three times, it was subjected to supercritical drying (9 Pa, 35°C, 2h) to obtain a transparent insulating aerogel film dynamically controlled by sunlight.

[0075] Example 2

[0076] The process is the same as Example 1, except that the aerogel precursor dispersion is poured into a 3 mm thick mold and then waited for gelation.

[0077] Example 3

[0078] The process is the same as Example 1, except that the aerogel precursor dispersion is poured into a 4 mm thick mold and then waited for gelation.

[0079] Example 4

[0080] The process is the same as Example 1, except that the aerogel precursor dispersion is poured into a 5 mm thick mold and then waited for gelation.

[0081] Example 5

[0082] The process is the same as Example 1, except that the aerogel precursor dispersion is poured into a 6 mm thick mold and then waited for gelation.

[0083] Example 6

[0084] The same as Example 2, except that the amount of phase change nanoparticles used is 0.14 g.

[0085] Example 7

[0086] The same as Example 2, except that the amount of phase change nanoparticles used is 0.27 g.

[0087] Comparative Example 1

[0088] The same as Example 2, except that no phase change nanoparticles are added.

[0089] Comparative Example 2

[0090] The same as Example 4, except that no phase change nanoparticles are added.

[0091] Comparative Example 3

[0092] The preparation method of the transparent aerogel film comprises the following steps:

[0093] S1: Weigh 186 mL of ethanol, 14.4 mL of deionized water, and 44.8 mL of ethyl orthosilicate and stir in a 50°C water bath to obtain dispersion A.

[0094] S2: Add an acidic solution (hydrochloric acid solution) to the dispersion A to adjust the pH to 3-4 to obtain the dispersion B, and stir at 50°C for 1.5 hours;

[0095] S3: Weigh 0.76 g of phase change nanoparticles (vanadium dioxide, particle size 10 nm), add it to dispersion B, stir and ultrasonicate to obtain dispersion C;

[0096] S4: Continue stirring and cool to room temperature, add ammonia water dropwise while stirring to adjust the pH value to 6-7 to obtain an aerogel precursor dispersion, pour it into a 3mm mold and wait for gelation;

[0097] S5: The obtained gel was subjected to solvent (methanol) replacement three times and then supercritical drying (9 Pa, 35° C., 2 h) to obtain a transparent aerogel film.

[0098] Figure 1 This is a scanning electron microscope image of the transparent insulating aerogel film dynamically regulated by sunlight obtained in Example 3, with a magnification of 50,000 times. It can be seen that the transparent insulating aerogel film dynamically regulated by sunlight obtained in the present invention has a three-dimensional nano-network structure, and the phase change nanoparticles are evenly distributed in the silicon aerogel without agglomeration.

[0099] Figure 2 This is a result diagram of the hydrophobic contact angle of the transparent thermal insulation aerogel film dynamically regulated by sunlight obtained in Example 3. It can be seen that the transparent thermal insulation aerogel film dynamically regulated by sunlight obtained in the present invention is hydrophobic.

[0100] Test the transmittance spectra of the transparent thermal insulation aerogel film dynamically regulated by sunlight at low temperature (20°C) and high temperature (42°C). Figure 3 The transmittance spectra of the sunlight dynamic regulation transparent thermal insulation aerogel film prepared in Example 3 at different temperatures show that the sunlight dynamic regulation transparent thermal insulation aerogel film prepared in the present invention has adaptive light and heat regulation and high light transmittance.

[0101] Table 1 shows the performance test results of the films prepared in the examples and comparative examples. It can be seen that the present invention produces a transparent insulating aerogel film with dynamic sunlight regulation and adaptive light and heat regulation, high light transmittance, and super insulation, which is suitable for high-end fields such as intelligent building curtain walls and spacecraft thermal control, and the sunlight transmittance can be regulated by up to 20.37%.

[0102] Table 1 Performance test results of the films obtained in the examples and comparative examples

[0103]

[0104]

[0105] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation thereto. It should be noted that those skilled in the art may make various improvements and modifications without departing from the principles of the present invention, and such improvements and modifications shall also be considered within the scope of protection of the present invention.

Claims

1. A transparent thermal insulation aerogel film dynamically regulated by sunlight, characterized in that: The invention comprises the following components in mass percentage: 0.5-1.5% of phase-change nanoparticles and 98.5-99.5% of silicon aerogel. The phase-change nanoparticles are distributed in the silicon aerogel, and the silicon aerogel is made of organic silane containing methyl.

2. The sunlight dynamic control transparent thermal insulation aerogel film according to claim 1, characterized in that: The organosilane includes methyltrimethoxysilane and / or methyltriethoxysilane.

3. The sunlight dynamically controlled transparent thermal insulation aerogel film according to claim 1, characterized in that: The phase-change nanoparticles include vanadium dioxide and / or tungsten trioxide.

4. The sunlight dynamically controlled transparent thermal insulation aerogel film according to claim 1 or 3, characterized in that: The particle size of the phase-change nanoparticles is 10-50 nm.

5. The sunlight dynamically controlled transparent thermal insulation aerogel film according to claim 1, characterized in that: The thickness of the sunlight dynamically regulated transparent thermal insulation aerogel film is 2 to 10 mm.

6. The method for preparing a transparent thermal insulation aerogel film dynamically controlled by sunlight according to any one of claims 1 to 5, characterized in that: The following steps are involved: dispersing the acidic solution and the organosilane to obtain a first dispersion; dispersing the first dispersion, a surfactant, water, and phase-change nanoparticles to obtain a second dispersion; The second dispersion is allowed to stand and then mixed with an alkaline solution to obtain an aerogel precursor dispersion, which is then gelled to obtain a gel; The gel is dried to obtain the sunlight dynamically regulated transparent thermal insulation aerogel film.

7. The preparation method according to claim 6, characterized in that The acidic solution includes one or more of a hydrochloric acid solution, an acetic acid solution and a nitric acid solution.

8. The preparation method according to claim 6, characterized in that The surfactant includes one or more of polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer, hexadecyltrimethylammonium bromide and hexadecyltrimethylammonium chloride.

9. The preparation method according to claim 6, characterized in that The alkaline solution includes one or more of ammonia water, urea and tetramethylammonium hydroxide solution.

10. Use of the sunlight-dynamically regulated transparent thermal insulation aerogel film according to any one of claims 1 to 5 or the sunlight-dynamically regulated transparent thermal insulation aerogel film prepared by the preparation method according to any one of claims 6 to 9 in the field of intelligent building curtain walls or spacecraft thermal control.

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