A Janus-structured temperature-controlled elastic material, its preparation method and application

Abstract

This invention discloses a Janus-structured temperature-controlled elastic material, its preparation method, and its applications. The Janus-structured temperature-controlled elastic material has a Janus double-layer structure, comprising a first structural layer and a second structural layer stacked on top of each other. The first structural layer has adjustable solar transmittance, with visible light transmittance ranging from 3% to 95%. The second structural layer has a highly efficient photothermal absorption and conversion function, with a photothermal conversion efficiency of 20% to 98%. This invention utilizes a black photothermal absorption and conversion elastomer as a substrate to absorb solar energy and convert it into heat. Furthermore, by adjusting the visible light transmittance of elastomers with different transmittance, the energy of transmitted visible light is controlled, thereby precisely controlling the photothermal conversion efficiency and achieving temperature regulation. It also has significant application potential in multiple fields such as passive solar heating, passive cooling, and infrared anti-counterfeiting.

Description

Technical Field

[0001] This invention relates to a gel elastomer material, and more particularly to a Janus structure temperature-controlled elastic material and its preparation method and application, especially in applications such as passive heating and cooling under sunlight and infrared anti-counterfeiting, belonging to the technical field of gel materials and organic-inorganic composite materials. Background Technology

[0002] Solar energy is the most promising renewable energy source on Earth, with an annual reserve of 340,000 EJ, ​​ten times the total amount of non-renewable energy. Currently, solar thermal conversion technology and its utilization have a long history, ranging from solar water heaters, solar dryers, and solar cells to solar desalination (seawater desalination) and solar power plants. However, most current temperature control technologies are relatively simple, and achieving precise temperature control across different energy sources using the inexhaustible energy source of solar energy remains a challenge.

[0003] Therefore, the question arises: can a novel material be developed that enables precise temperature control when utilizing the finite energy source of solar energy? Structurally, this material is based on a Janus structure, employing different structures on its front and back sides to control different temperatures under varying solar power. By adjusting the solar transmittance of its surface layer and utilizing the underlying black photothermal absorption and conversion elastomer to convert solar energy, programmed temperature control is achieved. Currently, this elastomer material differs from traditional solar energy utilization materials; it is a novel material and a novel structure.

[0004] Therefore, how to prepare elastic materials with different layers, what their unique properties and potential applications are all key questions that need to be solved and answered. First, the most difficult part is how to combine two elastomers with different properties. Second, the Janus structure is not a simple mixture of solutions for the two layers into a gel; this cannot form a uniform and effective conversion of solar energy into temperature. These are also key issues that need to be addressed. Summary of the Invention

[0005] The main objective of this invention is to provide a novel Janus-structured temperature-controlled elastic material and its preparation method, thereby overcoming the shortcomings of the prior art.

[0006] Another object of the present invention is to provide the application of the aforementioned Janus structure programmable temperature-controlled elastic material.

[0007] To achieve the aforementioned objectives, the present invention employs the following technical solution:

[0008] This invention provides a Janus structure temperature-controlled elastic material with a Janus double-layer structure. The Janus double-layer structure includes a first structural layer and a second structural layer stacked on top of each other. The first structural layer has adjustable solar transmittance, with visible light transmittance of 3% to 95%. The second structural layer has a high-efficiency photothermal absorption and conversion function, with a photothermal conversion efficiency of 20% to 98%.

[0009] Furthermore, the Janus structure temperature-controlled elastic material has a tensile fracture length of 50% to 500% and an elastic modulus of 20 kPa to 5000 kPa, and can achieve temperature control of 20°C to 80°C under sunlight.

[0010] This invention also provides a method for preparing a Janus-structured temperature-controlled elastic material, comprising:

[0011] (1) Provide an elastomer precursor with different permeability comprising nanoparticles, a first polymer hydrogel precursor solution, and a crosslinking agent;

[0012] (2) Crosslink a mixed system containing photothermal absorption and conversion components, a second polymer hydrogel precursor solution, and a crosslinking agent to generate a photothermal absorption and conversion elastomer;

[0013] (3) The elastomer precursors with different transmittances are applied to the photothermal absorption and conversion elastomer, and the Janus structure temperature-controlled elastic material is obtained by chemical or physical cross-linking.

[0014] This invention also provides a Janus-structured temperature-controlled elastic material prepared by the aforementioned method.

[0015] This invention also provides applications of the Janus structure programmable temperature-controlled elastic material in fields such as passive solar heating, passive cooling, or infrared anti-counterfeiting.

[0016] Compared with existing technologies, the advantages of this invention are as follows:

[0017] 1) The method for preparing Janus structure temperature-controlled elastic material provided by the present invention uses gel as functional unit, and adds nanoparticles to make them have different visible light transmittance. Based on the photothermal absorption conversion elastic substrate loaded with elastomers with different visible light transmittance, Janus structure elastomer is formed. This is a brand-new combination method. From the perspective of gel application and solar energy utilization, it is a new design idea and is expected to achieve important breakthroughs on the existing basis.

[0018] 2) This invention utilizes a black photothermal absorption and conversion elastomer as a substrate to absorb the energy of sunlight and convert it into heat. In addition, by adjusting the visible light transmittance of elastomers with different visible light transmittance, the energy of transmitted visible light can be controlled, thereby precisely controlling the photothermal conversion efficiency and achieving temperature regulation. Furthermore, it has great application potential in multiple fields such as passive heating and cooling of sunlight and infrared anti-counterfeiting. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 These are SEM images of elastomers with different visible light transmittance obtained in Example 1 of the present invention.

[0021] Figure 2 This is a SEM image of the black photothermal absorption conversion elastomer obtained in Example 2 of the present invention.

[0022] Figure 3 These are SEM images of elastomers with different visible light transmittance obtained in Example 3 of the present invention.

[0023] Figure 4 This is a SEM image of the black photothermal absorption conversion elastomer obtained in Example 4 of the present invention.

[0024] Figure 5 These are SEM images of elastomers with different visible light transmittance obtained in Example 5 of the present invention.

[0025] Figure 6 This is a tensile data diagram of the black photothermal absorption conversion elastomer obtained in Embodiment 6 of the present invention.

[0026] Figure 7 These are transmittance data graphs of elastomers with different visible light transmittance obtained in Examples 1-4 of the present invention.

[0027] Figure 8 This is a diagram of the experimental setup used in the test in Embodiment 11 of the present invention.

[0028] Figure 9 This is a test temperature curve of the Janus structure programmable temperature-controlled elastic material obtained in Examples 1-4 in Example 11 of the present invention. Detailed Implementation

[0029] Given the current limitations of solar energy photothermal conversion, the inventors of this invention, through long-term research and extensive practice, have proposed the design concept and technical solution of this invention. Its main mechanism is: using a black photothermal absorption and conversion elastomer as a base to absorb solar energy and convert it into heat; in addition, by adjusting the visible light transmittance of elastomers with different visible light transmittance, the energy of transmitted visible light is controlled, thereby precisely controlling the photothermal conversion efficiency and achieving temperature regulation.

[0030] The preparation method of this invention allows for precise temperature control using different structures on the front and back sides. The Janus-structured programmable temperature-controlled elastic material obtained in this invention's embodiments was used in experiments under a solar simulator, enabling control of different temperatures.

[0031] The following will provide a further explanation of the technical solution, its implementation process, and its principles.

[0032] One aspect of this invention provides a Janus-structured programmable temperature-controlled elastic material having a Janus double-layer structure. The Janus double-layer structure includes a first structural layer and a second structural layer stacked on top of each other. The first structural layer (hereinafter also defined as the "top layer") has adjustable solar transmittance, with visible light transmittance of 3% to 95%. The second structural layer (hereinafter also defined as the "bottom layer") has high-efficiency photothermal absorption and conversion capability, with photothermal conversion efficiency of 20% to 98%.

[0033] In some preferred embodiments, the visible light transmittance of the first structural layer having adjustable solar transmittance is between 10% and 50%.

[0034] In some preferred embodiments, the tensile fracture length of the Janus structure temperature-controlled elastic material is 50% to 500%, and the elastic modulus is 20 kPa to 5000 kPa. Under sunlight, it can achieve temperature control of 20°C to 80°C.

[0035] In some preferred embodiments, the first structural layer includes nanoparticles and a polymeric hydrogel elastomer. The nanoparticles include any one or a combination of two or more of aerogel particles, fumed silica particles, solid glass microspheres, hollow glass microspheres, etc., but are not limited thereto.

[0036] Furthermore, the particle size of the nanoparticles is 1–200 μm.

[0037] Furthermore, the content of nanoparticles in the first structural layer with adjustable solar transmittance (also referred to as "elastomer with different transmittance") is 0.02wt% to 20wt%.

[0038] Furthermore, the thickness of the first structural layer with adjustable solar transmittance is 1–6 mm.

[0039] Furthermore, the surface of the first structural layer with adjustable solar transmittance has a contact angle of 20–100° with water.

[0040] Furthermore, the elastic modulus of the first structural layer with adjustable solar transmittance is 0.020 MPa to 0.100 MPa.

[0041] In some implementations, the elastomers with different light transmittances comprise homogeneous composites consisting of nanoparticles, water, and a gel matrix.

[0042] In some preferred embodiments, the second structural layer includes a photothermal absorption and conversion component and a polymeric hydrogel elastomer. The photothermal absorption and conversion component (also referred to as "solid particles") includes any one or more of carbon nanotubes, graphene, graphite, conductive polymers, etc., but is not limited thereto.

[0043] In some embodiments, the particle size of the photothermal absorption and conversion component is 1–1000 μm.

[0044] In some embodiments, the content of the photothermal absorption and conversion component in the second structural layer (also referred to as "black photothermal absorption and conversion elastomer") is 15 wt% to 50 wt%.

[0045] In some embodiments, the thickness of the second structural layer (i.e., the black photothermal absorption and conversion elastomer) is 1 to 6 mm.

[0046] In some embodiments, the contact angle between the surface of the second structural layer (i.e., the black photothermal absorption and conversion elastomer) and water is 10 to 50°.

[0047] In some embodiments, the elastic modulus of the second structural layer (i.e., the black photothermal absorption and conversion elastomer) is 0.500 MPa to 1.000 MPa.

[0048] The Janus structure temperature-controlled elastic material of the present invention utilizes the second structural layer (i.e., black photothermal absorption and conversion elastomer) as a base to absorb the energy of sunlight and convert it into heat. In addition, by adjusting the visible light transmittance of the first structural layer (i.e., elastomers with different visible light transmittance), the energy of transmitted visible light is controlled, thereby precisely controlling the photothermal conversion efficiency and thus achieving temperature regulation.

[0049] Another aspect of the present invention provides a method for preparing a Janus-structured temperature-controlled elastic material, comprising:

[0050] (1) Provide an elastomer precursor with different permeability comprising nanoparticles, a first polymer hydrogel precursor solution, and a crosslinking agent;

[0051] (2) Crosslink a mixed system containing photothermal absorption and conversion components, a second polymer hydrogel precursor solution, and a crosslinking agent to generate a photothermal absorption and conversion elastomer;

[0052] (3) The elastomer precursors with different transmittances are applied to the photothermal absorption and conversion elastomer, and the Janus structure temperature-controlled elastic material is obtained by chemical or physical cross-linking.

[0053] In some preferred embodiments, in step (1), the nanoparticles include any one or a combination of two or more of aerogel particles, fumed silica particles, solid glass microspheres, hollow glass microspheres, etc., and their types and particle sizes are as described above, and will not be repeated here.

[0054] In some preferred embodiments, in step (1), the first polymeric hydrogel precursor contained in the first polymeric hydrogel precursor solution includes any one or more combinations of polyvinyl alcohol hydrogel, chitosan hydrogel, agarose hydrogel, sodium alginate hydrogel, polyacrylic acid hydrogel, sodium polyacrylate hydrogel, polyacrylamide hydrogel and polyethylene glycol hydrogel, but is not limited thereto.

[0055] In some embodiments, the mass fraction of the first polymeric hydrogel precursor in the first polymeric hydrogel precursor solution is 5 wt% to 15 wt%.

[0056] Furthermore, the content of nanoparticles in the elastomer precursors with different permeabilities is 0.02 wt% to 20 wt%.

[0057] Furthermore, the mass ratio of the nanoparticles to the first polymer hydrogel precursor solution is 1:10 to 1:200.

[0058] In some preferred embodiments, in step (2), the photothermal absorption and conversion component includes any one or more combinations of carbon nanotubes, graphene, graphite, conductive polymers, etc., and their types and particle sizes are as described above, and will not be repeated here.

[0059] In some preferred embodiments, in step (2), the second polymer hydrogel precursor (also known as an elastomer substrate) contained in the second polymer hydrogel precursor solution includes any one or more combinations of polyethylene glycol hydrogel, sodium alginate hydrogel, polyacrylic acid hydrogel, sodium polyacrylate hydrogel, polyacrylamide hydrogel, etc., but is not limited thereto.

[0060] The polymer hydrogel precursors used in steps (1) and (2) can be the same or different.

[0061] In some embodiments, the mass fraction of the second polymer hydrogel precursor in the second polymer hydrogel precursor solution is 5 wt% to 15 wt%.

[0062] Furthermore, the content of the photothermal absorption and conversion component in the photothermal absorption and conversion elastomer is 2wt% to 30wt%.

[0063] Furthermore, the mass ratio of the photothermal absorption and conversion component to the second polymer hydrogel precursor solution is 1:2 to 3:20.

[0064] In some preferred embodiments, in step (2), the temperature at which the crosslinking reaction generates the black photothermal absorption conversion elastomer is 30°C to 90°C, and the time for the crosslinking reaction is 0.3 to 5 hours.

[0065] In some preferred embodiments, in step (3), when the elastomer precursor with different transmittance is cast onto the photothermal absorption conversion elastomer, the temperature of the chemical or physical crosslinking reaction is 30°C to 90°C, preferably 50°C to 80°C, and the reaction time is 0.5 to 5 hours.

[0066] In some embodiments, in step (3), the thickness of the double layer is controlled between 1 and 6 mm depending on the amount of casting.

[0067] In some preferred embodiments, the mass ratio of the crosslinking agent to the first polymeric hydrogel precursor solution or the second polymeric hydrogel precursor solution is 1 to 10:100.

[0068] In some embodiments, the crosslinking agent includes propylene oxide, epichlorohydrin, glutaraldehyde, hexamethylene diisocyanate, 1,4-cyclohexane diisocyanate, trimethylhexamethylene diisocyanate, terephthalic diisocyanate, toluene diisocyanate, naphthalene 1,5-diisocyanate, 4,4'-methylenebis(phenyl isocyanate), 1,5-naphthalene diisocyanate, methylene diisocyanate, methyl-2,4-diisocyanate, diphenylmethane diisocyanate, isophenyl diisocyanate, 3,3-dimethyl-4,4′-diphenyl diisocyanate, isophorone diisocyanate, diisocyanate-based polyethylene glycol, ethyl(phenyl)di(di) The homopolymers of isocyanates, L-lysine diisocyanate, 3,3′-dichlorobiphenyl-4,4′-diisocyanate, 4-chloro-6-methyl-m-phenylene diisocyanate, 1-chloromethyl-2,4-diisocyanobenzene, 2,4-isocyanate-1-toluene, toluene 2,6-diisocyanate, m-phenylene diisocyanate, m-phenylene dimethyl isocyanate, 3,3′-dimethoxy-4,4′-biphenyl diisocyanate, 1,3-bis(1-isocyanate-1-methylethyl)benzene, 1,1',1″-methylenetris(4-isocyanate)benzene, and L-lysine triisocyanate, or combinations thereof, but not limited thereto.

[0069] In some preferred embodiments, the preparation method of the Janus structure temperature-controlled elastic material includes the following steps:

[0070] A black photothermal absorption and conversion elastomer was prepared using materials such as carbon nanotubes, graphene, graphite, and conductive polymers.

[0071] Nanoparticles were dispersed in a polymer hydrogel precursor solution to obtain elastomer precursors with different permeabilities.

[0072] Elastomer precursors with different transmittances are cast onto black photothermal absorption and conversion elastomers. Janus structure temperature-controlled elastic materials with certain elasticity and flexibility are synthesized through chemical or physical cross-linking. Precise temperature control is achieved by utilizing different light intensities and combinations of Janus structure transmittance and photothermal conversion efficiency.

[0073] In some more specific implementation examples, the preparation method of the Janus structure temperature-controlled elastic material includes the following steps:

[0074] (1) Disperse the solid particles, i.e. the photothermal absorption and conversion components, in a solvent to form a dispersion (which can be called "dispersion 1") for later use;

[0075] (2) Prepare polymer hydrogel precursors with different mass fractions as polymer hydrogel precursor solutions (which can be called "solution 1");

[0076] (3) Add dispersion 1 to solution 1, mix evenly, and then add crosslinking agent to chemically crosslink to form a black photothermal absorption conversion elastomer;

[0077] (4) Disperse the nanoparticles in a solvent to form a dispersion (which can be called "dispersion 2") for later use.

[0078] (5) Prepare polymer hydrogel precursors with different mass fractions as polymer hydrogel precursor solutions (which can be called "solution 2");

[0079] (6) Add dispersion 2 to solution 2, mix evenly, add crosslinking agent and cast onto black photothermal absorption conversion elastomer to form Janus structure programmable temperature control elastic material through chemical crosslinking.

[0080] In some preferred embodiments, step (1) of the preparation method specifically includes: stirring and mixing the solid particles evenly at room temperature.

[0081] In some preferred embodiments, step (4) of the preparation method specifically includes: stirring and mixing the nanoparticles uniformly at room temperature.

[0082] In summary, this invention presents a simple and low-cost method for preparing Janus-structured programmable temperature-controlled elastomer materials capable of precise temperature regulation. This method utilizes a double-layer structure for solar energy photothermal conversion, overcoming the limitations of traditional solar energy conversion technologies. By employing different light transmittances, the photothermal conversion layers achieve varying photothermal conversion efficiencies, successfully solving the current challenge of precise temperature control. The Janus-structured programmable temperature-controlled elastomer material of this invention can be applied to various devices or precision instruments, effectively reducing energy and fuel consumption and carbon emissions.

[0083] Another aspect of the present invention provides a Janus-structured temperature-controlled elastic material prepared by the aforementioned method.

[0084] Another aspect of this invention provides the application of the Janus structure programmable temperature-controlled elastic material, specifically, the application includes applications in fields such as passive solar heating, passive cooling, or infrared anti-counterfeiting.

[0085] The technical solution of the present invention will be further described in detail below with reference to several preferred embodiments and accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. It should be noted that the following embodiments are intended to facilitate understanding of the present invention, and do not constitute any limitation thereof. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Experimental methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or according to the conditions recommended by the manufacturer.

[0086] Example 1

[0087] (1) Preparation of aqueous solution of polymer hydrogel precursor: Take 10 g of polyethylene glycol, add it to 90 ml of deionized water, gradually heat to 80 °C, stir for 2-3 h until polyethylene glycol is completely dissolved, and obtain polyethylene glycol aqueous solution.

[0088] (2) Mixing of solid particles and polyethylene glycol solution: 1.5g of carbon nanotubes were added to 1g of ethanol and ultrasonically dispersed for 5 minutes. The dispersion containing carbon nanotubes was poured into 10g of polyethylene glycol aqueous solution. The mass ratio of the solid particles (carbon nanotubes) to the polymer gel precursor solution was 3:20. The mixture was stirred vigorously until it was evenly dispersed at a stirring speed of 500 rpm and ultrasonicated for 15 minutes. Then it was stirred vigorously and evenly to obtain a composite solution.

[0089] (3) Preparation of black photothermal absorption conversion elastomer: 1.5 mL of hydrochloric acid solution and 500 μL of propylene oxide aqueous solution (5 wt%) were added to the above composite solution. The mass ratio of the crosslinking agent to the polymer hydrogel precursor solution was 1:20. The mixture was stirred vigorously for 5 minutes at a stirring speed of 800 rpm. The mixture was then transferred to a mold and gelled at 30 °C for 5 h under nitrogen protection to obtain black photothermal absorption conversion elastomer.

[0090] (4) Mixing of nanoparticles and polyethylene glycol solution: 0.05g of fumed silica particles were added to 1g of ethanol and ultrasonically dispersed for 10 minutes. The dispersion containing the fumed silica particles was poured into 10g of polyethylene glycol aqueous solution. The mass ratio of the nanoparticles (fumed silica particles) to the polymer gel precursor solution was 1:200. The mixture was stirred until it was evenly dispersed at a stirring speed of 600 rpm and ultrasonicated for 15 minutes. Then, 1mL of hydrochloric acid solution and 500μL of propylene oxide aqueous solution (5wt%) were added to the above composite solution and stirred evenly to obtain composite solutions of materials with different transmittance.

[0091] (5) Preparation of Janus-structured temperature-controlled elastomer material: The composite solution of materials with different transmittances obtained in step (4) was poured onto the black photothermal absorption and conversion elastomer obtained in step (3). Gel was performed at 90°C for 30 min under nitrogen protection to obtain the Janus-structured temperature-controlled elastomer material. Characterization showed that the transmittance of individual elastomers with different transmittances on the surface of this Janus-structured temperature-controlled elastomer material was 0.130. SEM images are shown below. Figure 1 Other physical parameters are shown in Table 1.

[0092] Example 2

[0093] (1) Preparation of aqueous solution of polymer hydrogel precursor: Take 5g of sodium alginate, add it to 95ml of deionized water, gradually heat to 85℃, stir for 2-3h until sodium alginate is completely dissolved, and obtain sodium alginate aqueous solution.

[0094] (2) Mixing of solid particles with sodium alginate solution: Add 2g of graphite to 2g of ethanol and sonicate for 5 minutes to disperse. Pour the dispersion containing graphite into 10g of sodium alginate aqueous solution. The mass ratio of the solid particles (graphite) to the polymer gel precursor solution is 1:5. Stir until uniformly dispersed at a stirring speed of 400 rpm, sonicate for 15 minutes, and then stir vigorously and uniformly to obtain a composite solution.

[0095] (3) Preparation of black photothermal absorption conversion elastomer: 1.5 mL of hydrochloric acid solution and 100 μL of glutaraldehyde aqueous solution (5 wt%) were added to the above composite solution. The mass ratio of the crosslinking agent to the polymer hydrogel precursor solution was 1:100. The mixture was stirred vigorously for 5 minutes at a stirring speed of 800 rpm. The mixture was then transferred to a mold and gelled at 90 °C for 18 min under nitrogen protection to obtain black photothermal absorption conversion elastomer.

[0096] (4) Mixing of nanoparticles and sodium alginate solution: 0.1g of hollow glass microspheres were added to 1g of ethanol and ultrasonically dispersed for 10 minutes. The dispersion containing hollow glass microspheres was poured into 10g of sodium alginate aqueous solution. The mass ratio of the nanoparticles (hollow glass microspheres) to the polymer gel precursor solution was 1:100. The mixture was stirred until it was evenly dispersed at a stirring speed of 600 rpm and ultrasonicated for 15 minutes. Then, 1.5mL of hydrochloric acid solution and 500μL of glutaraldehyde aqueous solution (5wt%) were added to the above composite solution and stirred evenly to obtain composite solutions of materials with different transmittance.

[0097] (5) Preparation of Janus-structured temperature-controlled elastomer material: The composite solution of materials with different transmittances obtained in step (4) was poured onto the black photothermal absorption-conversion elastomer obtained in step (3). Gel was carried out at 75°C for 40 min under nitrogen protection to obtain the Janus-structured temperature-controlled elastomer material. Characterization showed that the transmittance of individual elastomers with different transmittances on the surface of this Janus-structured temperature-controlled elastomer material was 0.101. SEM images of the black photothermal absorption-conversion elastomer are shown below. Figure 2 Other physical parameters are shown in Table 1.

[0098] Example 3

[0099] (1) Preparation of aqueous solution of polymer hydrogel precursor: Take 10 g of polyacrylic acid, add it to 90 ml of deionized water, gradually heat to 80 °C, stir for 2-3 h until the polyacrylic acid is completely dissolved, and obtain the aqueous solution of polyacrylic acid.

[0100] (2) Mixing of solid particles with polyacrylic acid solution: 1.5g of carbon nanotubes were added to 1g of ethanol and ultrasonically dispersed for 5 minutes. The dispersion containing carbon nanotubes was poured into 10g of polyacrylic acid aqueous solution. The mass ratio of the solid particles (carbon nanotubes) to the polymer gel precursor solution was 3:20. The mixture was stirred until it was evenly dispersed at a stirring speed of 400 rpm and ultrasonicated for 15 minutes. Then it was stirred vigorously and evenly to obtain a composite solution.

[0101] (3) Preparation of black photothermal absorption conversion elastomer: 1.5 mL of hydrochloric acid solution and 1 mL of epichlorohydrin aqueous solution (5 wt%) were added to the above composite solution. The mass ratio of the crosslinking agent to the polymer hydrogel precursor solution was 1:10. The mixture was stirred vigorously for 5 minutes at a stirring speed of 600 rpm. The mixture was then transferred to a mold and gelled at 60 °C for 50 min under nitrogen protection to obtain black photothermal absorption conversion elastomer.

[0102] (4) Mixing of nanoparticles and polyacrylic acid solution: 0.2g of fumed silica particles were added to 1g of ethanol and ultrasonically dispersed for 10 minutes. The dispersion containing the fumed silica particles was poured into 10g of polyacrylic acid aqueous solution. The mass ratio of the nanoparticles (fumed silica particles) to the polymer gel precursor solution was 1:50. The mixture was stirred until it was evenly dispersed at a stirring speed of 900 rpm and ultrasonicated for 15 minutes. Then, 1.5mL of hydrochloric acid solution and 500μL of epichlorohydrin aqueous solution (5wt%) were added to the above composite solution and stirred evenly to obtain composite solutions of materials with different transmittance.

[0103] (5) Preparation of Janus-structured temperature-controlled elastomer material: The composite solution of materials with different transmittances obtained in step (4) was poured onto the black photothermal absorption and conversion elastomer obtained in step (3). Gel was carried out at 50°C for 2 hours under nitrogen protection to obtain the Janus-structured temperature-controlled elastomer material. Characterization showed that the transmittance of individual elastomers with different transmittances on the surface of this Janus-structured temperature-controlled elastomer material was 0.085. SEM images are shown below. Figure 3 Other physical parameters are shown in Table 1.

[0104] Example 4

[0105] (1) Preparation of aqueous solution of polymer hydrogel precursor: Take 10 g of polyethylene glycol, add it to 90 ml of deionized water, gradually heat to 80 °C, stir for 2-3 h until polyethylene glycol is completely dissolved, and obtain polyethylene glycol aqueous solution.

[0106] (2) Mixing of solid particles and polyethylene glycol solution: 3g of carbon nanotubes were added to 3g of ethanol and ultrasonically dispersed for 5 minutes. The dispersion containing carbon nanotubes was poured into 10g of polyethylene glycol aqueous solution. The mass ratio of the solid particles (carbon nanotubes) to the polymer gel precursor solution was 3:10. The mixture was stirred vigorously until it was evenly dispersed at a stirring speed of 550 rpm and ultrasonicated for 15 minutes. Then it was stirred vigorously and evenly to obtain a composite solution.

[0107] (3) Preparation of black photothermal absorption conversion elastomer: 1.5 mL of hydrochloric acid solution and 500 μL of glutaraldehyde aqueous solution (5 wt%) were added to the above composite solution. The mass ratio of the crosslinking agent to the polymer hydrogel precursor solution was 1:20. The mixture was stirred vigorously for 5 minutes at a stirring speed of 700 rpm. The mixture was then transferred to a mold and gelled at 70 °C for 30 min under nitrogen protection to obtain black photothermal absorption conversion elastomer.

[0108] (4) Mixing of nanoparticles and polyethylene glycol solution: 0.5g of fumed silica particles were added to 1g of ethanol and ultrasonically dispersed for 10 minutes. The dispersion containing the fumed silica particles was then poured into 10g of polyethylene glycol aqueous solution. The mass ratio of the nanoparticles (fumed silica particles) to the polymer gel precursor solution was 1:20. The mixture was stirred until it was evenly dispersed at a stirring speed of 600 rpm and ultrasonicated for 15 minutes. Then, 1.5mL of hydrochloric acid solution and 500μL of glutaraldehyde aqueous solution (5wt%) were added and stirred evenly to obtain a composite solution of materials with different transmittance.

[0109] (5) Preparation of Janus-structured temperature-controlled elastomer material: The composite solution of materials with different transmittances obtained in step (4) was poured onto the black photothermal absorption-conversion elastomer obtained in step (3). Gel was carried out at 30°C for 5 hours under nitrogen protection to obtain the Janus-structured temperature-controlled elastomer material. Characterization showed that the transmittance of individual elastomers with different transmittances on the surface of this Janus-structured temperature-controlled elastomer material was 0.072. SEM images of the black photothermal absorption-conversion elastomer are shown below. Figure 4 Other physical parameters are shown in Table 1.

[0110] Example 5

[0111] (1) Preparation of aqueous solution of polymer hydrogel precursor: Take 7g of sodium alginate, add it to 93ml of deionized water, gradually heat to 85℃, stir for 2-3h until sodium alginate is completely dissolved, and obtain sodium alginate aqueous solution.

[0112] (2) Mixing of solid particles with sodium alginate solution: 2g of conductive polymer is added to 2g of ethanol and ultrasonically dispersed for 5 minutes. The dispersion containing the conductive polymer is poured into 10g of sodium alginate aqueous solution. The mass ratio of the solid particles (conductive polymer) to the polymer gel precursor solution is 1:5. The mixture is stirred until it is evenly dispersed at a stirring speed of 400 rpm and ultrasonicated for 15 minutes. Then it is stirred vigorously and evenly to obtain a composite solution.

[0113] (3) Preparation of black photothermal absorption conversion elastomer: 2 mL of hydrochloric acid solution and 300 μL of terephthalic diisocyanate aqueous solution (5 wt%) were added to the above composite solution. The mass ratio of the crosslinking agent to the polymer hydrogel precursor solution was 3:100. The mixture was stirred vigorously for 5 minutes at a stirring speed of 300 rpm. The mixture was then transferred to a mold and gelled at 75 °C for 35 min under nitrogen protection to obtain black photothermal absorption conversion elastomer.

[0114] (4) Mixing of nanoparticles and sodium alginate solution: 0.7g of hollow glass microspheres were added to 1g of ethanol and ultrasonically dispersed for 10 minutes. The dispersion containing hollow glass microspheres was poured into 10g of sodium alginate aqueous solution. The mass ratio of the nanoparticles (hollow glass microspheres) to the polymer gel precursor solution was 7:100. The mixture was stirred until it was evenly dispersed at a stirring speed of 800 rpm and ultrasonicated for 15 minutes. Then, 2mL of hydrochloric acid solution and 300μL of terephthalic diisocyanate aqueous solution (5wt%) were added to the above composite solution and stirred evenly to obtain composite solutions of materials with different transmittance.

[0115] (5) Preparation of Janus-structured temperature-controlled elastomer material: The composite solution of materials with different transmittances obtained in step (4) was poured onto the black photothermal absorption and conversion elastomer obtained in step (3). Gel was carried out at 70°C for 45 min under nitrogen protection to obtain the Janus-structured temperature-controlled elastomer material. Characterization showed that the transmittance of individual elastomers with different transmittances on the surface of this Janus-structured temperature-controlled elastomer material was 0.075. SEM images are shown below. Figure 5 Other physical parameters are shown in Table 1.

[0116] Example 6

[0117] (1) Preparation of aqueous solution of polymer hydrogel precursor: Take 10 g of polyacrylic acid, add it to 90 ml of deionized water, gradually heat to 80 °C, stir for 2-3 h until the polyacrylic acid is completely dissolved, and obtain the aqueous solution of polyacrylic acid.

[0118] (2) Mixing of solid particles and polyacrylic acid solution: Add 5g of graphite to 5g of ethanol and sonicate for 5 minutes to disperse. Pour the dispersion containing graphite into 10g of polyacrylic acid aqueous solution. The mass ratio of the solid particles (graphite) to the polymer gel precursor solution is 1:2. Stir until uniformly dispersed at a stirring speed of 600 rpm, sonicate for 15 minutes, and then stir vigorously and uniformly to obtain a composite solution.

[0119] (3) Preparation of black photothermal absorption conversion elastomer: 1.5 mL of hydrochloric acid solution and 600 μL of epichlorohydrin aqueous solution (5 wt%) were added to the above composite solution. The mass ratio of the crosslinking agent to the polymer hydrogel precursor solution was 3:50. The mixture was stirred vigorously for 5 minutes at a stirring speed of 600 rpm. The mixture was then transferred to a mold and gelled at 60 °C for 50 min under nitrogen protection to obtain black photothermal absorption conversion elastomer.

[0120] (4) Mixing of nanoparticles and polyacrylic acid solution: 1g of fumed silica particles were added to 1g of ethanol and ultrasonically dispersed for 10 minutes. The dispersion containing the fumed silica particles was poured into 10g of polyacrylic acid aqueous solution. The mass ratio of the nanoparticles (fumed silica particles) to the polymer gel precursor solution was 1μ10. The mixture was stirred until it was evenly dispersed at a stirring speed of 900 rpm and ultrasonicated for 15 minutes. Then, 1.5mL of hydrochloric acid solution and 600μL of epichlorohydrin aqueous solution (5wt%) were added to the above composite solution and stirred evenly to obtain composite solutions of materials with different transmittance.

[0121] (5) Preparation of Janus structure temperature-controlled elastomer material: The composite solution of materials with different transmittances obtained in step (4) above was poured onto the black photothermal absorption and conversion elastomer obtained in step (3) above. Gel was performed at 80℃ for 30 min under nitrogen protection to obtain the Janus structure temperature-controlled elastomer material. Characterization showed that the transmittance of individual elastomers with different transmittances on the surface of this Janus structure temperature-controlled elastomer material was 0.048. The tensile data of the black photothermal absorption and conversion elastomer are shown in […]. Figure 6 Other physical parameters are shown in Table 1.

[0122] Table 1. Physical property parameters of the Janus structure temperature-programmed elastomer materials obtained in Examples 1-6 (light intensity: 160mW / m²) -2 )

[0123]

[0124] Example 7

[0125] (1) Preparation of aqueous solution of polymer hydrogel precursor: Take 10 g of polyethylene glycol, add it to 90 ml of deionized water, gradually heat to 80 °C, stir for 2-3 h until polyethylene glycol is completely dissolved, and obtain polyethylene glycol aqueous solution.

[0126] (2) Mixing of solid particles and polyethylene glycol solution: 1g of graphene was added to 1g of ethanol and ultrasonically dispersed for 5 minutes. The dispersion containing graphene was poured into 10g of polyethylene glycol aqueous solution. The mass ratio of the solid particles (graphene) to the polymer gel precursor solution was 1:10. The mixture was stirred vigorously until it was evenly dispersed at a stirring speed of 500 rpm and ultrasonicated for 15 minutes. Then it was stirred vigorously and evenly to obtain a composite solution.

[0127] (3) Preparation of black photothermal absorption conversion elastomer: 1.5 mL of hydrochloric acid solution and 300 μL of propylene oxide aqueous solution (5 wt%) were added to the above composite solution. The mass ratio of the crosslinking agent to the polymer hydrogel precursor solution was 3:100. The mixture was stirred vigorously for 5 minutes at a stirring speed of 800 rpm. The mixture was then transferred to a mold and gelled at 60 °C for 1 h under nitrogen protection to obtain black photothermal absorption conversion elastomer.

[0128] (4) Mixing of nanoparticles and polyethylene glycol solution: 0.05g of solid glass microspheres were added to 1g of ethanol and ultrasonically dispersed for 10 minutes. The dispersion containing the solid glass microspheres was poured into 10g of polyethylene glycol aqueous solution. The mass ratio of the nanoparticles (solid glass microspheres) to the polymer gel precursor solution was 1:200. The mixture was stirred until it was uniformly dispersed at a stirring speed of 600 rpm and ultrasonicated for 15 minutes. Then, 1.5mL of hydrochloric acid solution and 300μL of propylene oxide aqueous solution (5wt%) were added to the above composite solution and stirred uniformly to obtain composite solutions of materials with different transmittance.

[0129] (5) Preparation of Janus structure temperature-controlled elastomer material: The composite solution of materials with different light transmittances obtained in step (4) above is poured onto the black photothermal absorption and conversion elastomer obtained in step (3) above. Under nitrogen protection, gel at 80℃ for 30 min to obtain Janus structure temperature-controlled elastomer material.

[0130] Example 8

[0131] (1) Preparation of aqueous solution of polymer hydrogel precursor: Take 10 g of polyacrylic acid, add it to 90 ml of deionized water, gradually heat to 80 °C, stir for 2-3 h until the polyacrylic acid is completely dissolved, and obtain the aqueous solution of polyacrylic acid.

[0132] (2) Mixing of solid particles with polyacrylic acid solution: 1.5g of carbon nanotubes were added to 1g of ethanol and ultrasonically dispersed for 5 minutes. The dispersion containing carbon nanotubes was poured into 10g of polyacrylic acid aqueous solution. The mass ratio of the solid particles (carbon nanotubes) to the polymer gel precursor solution was 3:20. The mixture was stirred until it was evenly dispersed at a stirring speed of 400 rpm and ultrasonicated for 15 minutes. Then it was stirred vigorously and evenly to obtain a composite solution.

[0133] (3) Preparation of black photothermal absorption conversion elastomer: 1.5 mL of hydrochloric acid solution and 500 μL of glutaraldehyde aqueous solution (5 wt%) were added to the above composite solution. The mass ratio of the crosslinking agent to the polymer hydrogel precursor solution was 1:20. The mixture was stirred vigorously for 5 minutes at a stirring speed of 600 rpm. The mixture was then transferred to a mold and gelled at 80 °C for 50 min under nitrogen protection to obtain black photothermal absorption conversion elastomer.

[0134] (4) Mixing of nanoparticles and polyacrylic acid solution: 1g of aerogel particles were added to 1g of ethanol and ultrasonically dispersed for 10 minutes. The dispersion containing the aerogel particles was poured into 10g of polyacrylic acid aqueous solution. The mass ratio of the nanoparticles (aerogel particles) to the polymer gel precursor solution was 1:10. The mixture was stirred until it was evenly dispersed at a stirring speed of 900 rpm and ultrasonically for 15 minutes. Then, 1.5mL of hydrochloric acid solution and 500μL of glutaraldehyde aqueous solution (5wt%) were added to the above composite solution and stirred evenly to obtain composite solutions of materials with different transmittance.

[0135] (5) Preparation of Janus structure temperature-controlled elastomer material: The composite solution of materials with different transmittances obtained in step (4) above is poured onto the black photothermal absorption and conversion elastomer obtained in step (3) above. Gel at 80°C for 35 min under nitrogen protection to obtain Janus structure temperature-controlled elastomer material.

[0136] Example 9

[0137] (1) Preparation of aqueous solution of polymer hydrogel precursor: Take 10 g of sodium polyacrylate, add it to 90 ml of deionized water, gradually heat to 80 °C, stir for 2-3 h until the polyacrylate is completely dissolved, and obtain sodium polyacrylate aqueous solution.

[0138] (2) Mixing of solid particles with sodium polyacrylate solution: 1.5g of carbon nanotubes were added to 1g of ethanol and ultrasonically dispersed for 5 minutes. The dispersion containing carbon nanotubes was poured into 10g of sodium polyacrylate aqueous solution. The mass ratio of the solid particles (carbon nanotubes) to the polymer gel precursor solution was 3:20. The mixture was stirred until it was evenly dispersed at a stirring speed of 400 rpm and ultrasonicated for 15 minutes. Then it was stirred vigorously and evenly to obtain a composite solution.

[0139] (3) Preparation of black photothermal absorption conversion elastomer: 1.5 mL of hydrochloric acid solution and 500 μL of glutaraldehyde aqueous solution (5 wt%) were added to the above composite solution. The mass ratio of the crosslinking agent to the polymer hydrogel precursor solution was 1:20. The mixture was stirred vigorously for 5 minutes at a stirring speed of 600 rpm. The mixture was then transferred to a mold and gelled at 80 °C for 50 min under nitrogen protection to obtain black photothermal absorption conversion elastomer.

[0140] (4) Mixing of nanoparticles with sodium polyacrylate solution: 1g of aerogel particles were added to 1g of ethanol and ultrasonically dispersed for 10 minutes. The dispersion containing the aerogel particles was then poured into 10g of sodium polyacrylate aqueous solution. The mass ratio of the nanoparticles (aerogel particles) to the polymer gel precursor solution was 1:10. The mixture was stirred until it was evenly dispersed at a stirring speed of 900 rpm and ultrasonically for 15 minutes. Then, 1.5mL of hydrochloric acid solution and 500μL of glutaraldehyde aqueous solution (5wt%) were added to the above composite solution and stirred evenly to obtain composite solutions of materials with different transmittance.

[0141] (5) Preparation of Janus structure temperature-controlled elastomer material: The composite solution of materials with different transmittances obtained in step (4) above is poured onto the black photothermal absorption and conversion elastomer obtained in step (3) above. Gel at 80°C for 35 min under nitrogen protection to obtain Janus structure temperature-controlled elastomer material.

[0142] Example 10

[0143] (1) Preparation of aqueous solution of polymer hydrogel precursor: Take 10 g of polyacrylamide, add it to 90 ml of deionized water, gradually heat to 80 °C, stir for 2-3 h until the polyacrylamide is completely dissolved, and obtain an aqueous solution of polyacrylamide.

[0144] (2) Mixing of solid particles and polyacrylamide solution: 1.5g of carbon nanotubes were added to 1g of ethanol and ultrasonically dispersed for 5 minutes. The dispersion containing carbon nanotubes was poured into 10g of polyacrylamide aqueous solution. The mass ratio of the solid particles (carbon nanotubes) to the polymer gel precursor solution was 3:20. The mixture was stirred until it was evenly dispersed at a stirring speed of 400 rpm and ultrasonicated for 15 minutes. Then it was stirred vigorously and evenly to obtain a composite solution.

[0145] (3) Preparation of black photothermal absorption conversion elastomer: 1.5 mL of hydrochloric acid solution and 500 μL of glutaraldehyde aqueous solution (5 wt%) were added to the above composite solution. The mass ratio of the crosslinking agent to the polymer hydrogel precursor solution was 1:20. The mixture was stirred vigorously for 5 minutes at a stirring speed of 600 rpm. The mixture was then transferred to a mold and gelled at 80 °C for 50 min under nitrogen protection to obtain black photothermal absorption conversion elastomer.

[0146] (4) Mixing of nanoparticles and polyacrylamide solution: 1g of aerogel particles were added to 1g of ethanol and ultrasonically dispersed for 10 minutes. The dispersion containing the aerogel particles was poured into 10g of polyacrylamide aqueous solution. The mass ratio of the nanoparticles (aerogel particles) to the polymer gel precursor solution was 1:10. The mixture was stirred until it was evenly dispersed at a stirring speed of 900 rpm and ultrasonically for 15 minutes. Then, 1.5mL of hydrochloric acid solution and 500μL of glutaraldehyde aqueous solution (5wt%) were added to the above composite solution and stirred evenly to obtain composite solutions of materials with different transmittance.

[0147] (5) Preparation of Janus structure temperature-controlled elastomer material: The composite solution of materials with different transmittances obtained in step (4) above is poured onto the black photothermal absorption and conversion elastomer obtained in step (3) above. Gel at 50°C for 2 hours under nitrogen protection to obtain Janus structure temperature-controlled elastomer material.

[0148] Compare with Example 1

[0149] (1) Black base: Use commercially available black carbon film directly.

[0150] (2) Mixing of nanoparticles and polyethylene glycol solution: 0.05g of solid glass microspheres were added to 1g of ethanol and ultrasonically dispersed for 10 minutes. The dispersion containing the solid glass microspheres was poured into 10g of polyethylene glycol aqueous solution. The mass ratio of the nanoparticles to the polymer gel precursor solution was 1:200. The mixture was stirred until it was evenly dispersed at a stirring speed of 600 rpm and ultrasonically for 15 minutes. Then it was stirred evenly to obtain a composite solution of materials with different transmittance.

[0151] (3) Preparation of elastic materials: The composite solution of materials with different transmittances obtained in step (2) above was poured onto the carbon film prepared in step (1) above. Gel was carried out at 80°C for 30 min under nitrogen protection. The relevant parameters of the obtained materials are shown in Table 2.

[0152] Compare with Example 2

[0153] (1) Black base: Use commercially available black glass plates directly.

[0154] (2) Mixing of nanoparticles and polyethylene glycol solution: 0.1g of fumed silica particles were added to 1g of ethanol and ultrasonically dispersed for 10 minutes. The dispersion containing the fumed silica particles was poured into 10g of polyethylene glycol aqueous solution. The mass ratio of the nanoparticles to the polymer gel precursor solution was 1:200. The mixture was stirred until it was evenly dispersed at a stirring speed of 600 rpm and ultrasonically for 15 minutes. Then it was stirred evenly to obtain a composite solution of materials with different transmittance.

[0155] (3) Preparation of elastic materials: The composite solution of materials with different transmittances obtained in step (2) above was poured onto the carbon film prepared in step (1) above. Gel was carried out at 80°C for 30 min under nitrogen protection. The relevant parameters of the obtained materials are shown in Table 2.

[0156] Compare with Example 3

[0157] (1) Preparation of aqueous solution of polymer hydrogel precursor: Take 10 g of polyacrylic acid, add it to 90 ml of deionized water, gradually heat to 80 °C, stir for 2-3 h until the polyacrylic acid is completely dissolved, and obtain the aqueous solution of polyacrylic acid.

[0158] (2) Mixing of solid particles with polyacrylic acid solution: 1.5g of carbon nanotubes were added to 1g of ethanol and ultrasonically dispersed for 5 minutes. The dispersion containing carbon nanotubes was poured into 10g of polyacrylic acid aqueous solution. The mass ratio of the solid particles (carbon nanotubes) to the polymer gel precursor solution was 3:20. The mixture was stirred until it was evenly dispersed at a stirring speed of 400 rpm and ultrasonicated for 15 minutes. Then it was stirred vigorously and evenly to obtain a composite solution.

[0159] (3) Preparation of black photothermal absorption conversion elastomer: 1.5 mL of hydrochloric acid solution and 500 μL of glutaraldehyde aqueous solution (5 wt%) were added to the above composite solution. The mass ratio of the crosslinking agent to the polymer hydrogel precursor solution was 1:20. The mixture was stirred vigorously for 5 minutes at a stirring speed of 600 rpm. The mixture was then transferred to a mold and gelled at 80 °C for 50 min under nitrogen protection to obtain black photothermal absorption conversion elastomer.

[0160] (4) Preparation of transparent elastomer: Take 10g of polyacrylic acid aqueous solution, add 1.5mL of hydrochloric acid solution and 500μL of glutaraldehyde aqueous solution (5wt%) to the above composite solution. The mass ratio of the crosslinking agent to the polymer hydrogel precursor solution is 1:20. Stir vigorously for 5 minutes at a stirring speed of 600rpm to obtain a transparent solution.

[0161] (5) Preparation of Janus structure temperature-controlled elastomer material: The transparent solution obtained in step (4) above was poured onto the black photothermal absorption and conversion elastomer obtained in step (3) above. Under nitrogen protection, gel at 80℃ for 35 min to obtain Janus structure temperature-controlled elastomer material. The relevant parameters are shown in Table 2.

[0162] Compare with Example 4

[0163] (1) Preparation of aqueous solution of polymer hydrogel precursor: Take 7g of sodium alginate, add it to 93ml of deionized water, gradually heat to 85℃, stir for 2-3h until sodium alginate is completely dissolved, and obtain sodium alginate aqueous solution.

[0164] (2) Mixing of solid particles with sodium alginate solution: 2g of carbon nanotubes were added to 2g of ethanol and ultrasonicated for 5 minutes to disperse them. The dispersion containing carbon nanotubes was poured into 10g of sodium alginate aqueous solution. The mass ratio of the solid particles to the polymer gel precursor solution was 1:5. The mixture was stirred until it was evenly dispersed at a stirring speed of 400 rpm and ultrasonicated for 15 minutes. Then it was stirred vigorously and evenly to obtain a composite solution.

[0165] (3) Preparation of Janus structure material: 2 mL of hydrochloric acid solution and 300 μL of terephthalic diisocyanate aqueous solution (5 wt%) were added to the above composite solution and stirred vigorously for 5 minutes at a stirring speed of 300 rpm. The mixture was then transferred to a mold and covered with a transparent plastic wrap as a transparent layer. The mixture was gelled at 65 °C for 30 min under nitrogen protection to obtain Janus structure temperature-controlled elastomer material. The relevant parameters are shown in Table 2.

[0166] Table 2. Relevant performance parameters of the materials obtained in Comparative Examples 1-4 (Light intensity: 160 mW / m²) -2 )

[0167]

[0168] Compared with the control example, the control example has a lower modulus, poorer mechanical properties, poorer temperature control ability, and no temperature gradient change.

[0169] Example 11

[0170] The inventors of this case also conducted performance tests on the Janus structure programmable temperature-controlled elastomer materials obtained from the above embodiments and comparative examples.

[0171] Figure 7 These are transmittance data graphs of elastomers with different visible light transmittance obtained in Examples 1-4. Figure 8 A diagram of the experimental setup used in the test is shown. Figure 9 The temperature curves of the Janus structure programmed temperature-controlled elastomer materials obtained in Examples 1-4 are shown in the test graphs under a solar simulator.

[0172] In addition, the inventors of this case also conducted experiments with other raw materials, process operations, and process conditions described in this specification, referring to the aforementioned embodiments, and obtained relatively ideal results in all cases.

[0173] It should be understood that the above examples are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be used to limit the scope of protection of the present invention. All equivalent transformations or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A Janus-structured programmable temperature-controlled elastic material, characterized in that: The Janus-structured temperature-controlled elastic material has a Janus double-layer structure, comprising a first structural layer and a second structural layer stacked on top of each other. The first structural layer has adjustable solar transmittance, with visible light transmittance ranging from 3% to 95%. The first structural layer comprises nanoparticles and a polymeric hydrogel elastomer. The nanoparticles are selected from any one or a combination of two or more of aerogel particles, fumed silica particles, solid glass microspheres, and hollow glass microspheres. The surface of the first structural layer has a water contact angle of 20° to 100°. The elastic modulus of the first structural layer is 0.020 MPa to 0.100 MPa; the second structural layer has a highly efficient photothermal absorption and conversion function, with a photothermal conversion efficiency of 20% to 98%; the second structural layer includes a photothermal absorption and conversion component and a polymeric hydrogel elastomer, wherein the photothermal absorption and conversion component is selected from any one or a combination of two or more of carbon nanotubes, graphene, graphite, and conductive polymers; the contact angle between the surface of the second structural layer and water is 10 to 50°, and the elastic modulus of the second structural layer is 0.500 MPa to 1.000 MPa; The Janus structure temperature-controlled elastic material has a tensile fracture length of 50% to 500% and an elastic modulus of 20 kPa to 5000 kPa. Under sunlight, it can achieve a temperature-controlled program from 20°C to 80°C. The preparation method of the Janus structure temperature-controlled elastic material includes: (1) Provides an elastomer precursor with different permeability comprising nanoparticles, a first polymer hydrogel precursor solution, and a crosslinking agent, wherein the nanoparticles are selected from any one or a combination of two or more of aerogel particles, fumed silica particles, solid glass microspheres, and hollow glass microspheres; the first polymer hydrogel precursor contained in the first polymer hydrogel precursor solution is selected from any one or a combination of two or more of polyvinyl alcohol hydrogel, chitosan hydrogel, agarose hydrogel, sodium alginate hydrogel, polyacrylic acid hydrogel, sodium polyacrylate hydrogel, polyacrylamide hydrogel, and polyethylene glycol hydrogel; the content of nanoparticles in the elastomer precursor with different permeability is 0.02wt%~20wt%; the mass fraction of the first polymer hydrogel precursor in the first polymer hydrogel precursor solution is 5wt%~15wt%; and the mass ratio of the nanoparticles to the first polymer hydrogel precursor solution is 1:10~1:

200. (2) A photothermal absorption and conversion elastomer is generated by crosslinking a mixture containing a photothermal absorption and conversion component, a second polymer hydrogel precursor solution, and a crosslinking agent. The photothermal absorption and conversion component is selected from any one or a combination of two or more of carbon nanotubes, graphene, graphite, and conductive polymers. The second polymer hydrogel precursor solution contains a second polymer hydrogel precursor selected from any one or a combination of two or more of polyethylene glycol hydrogel, sodium alginate hydrogel, polyacrylic acid hydrogel, sodium polyacrylate hydrogel, and polyacrylamide hydrogel. The content of the photothermal absorption and conversion component is 2wt%~30wt%; the temperature for the crosslinking reaction to generate the photothermal absorption and conversion elastomer is 30℃~90℃, and the crosslinking reaction time is 0.3~5h; the mass fraction of the second polymer hydrogel precursor in the second polymer hydrogel precursor solution is 5wt%~15wt%; the mass ratio of the photothermal absorption and conversion component to the second polymer hydrogel precursor solution is 1:2~3:20; the mass ratio of the crosslinking agent to the first polymer hydrogel precursor solution or the second polymer hydrogel precursor solution is 1~10:100; (3) The elastomer precursors with different transmittances are cast onto the photothermal absorption and conversion elastomer, and the Janus structure temperature-controlled elastic material is obtained by chemical or physical cross-linking. The temperature of the chemical or physical cross-linking reaction is 30℃~90℃, and the reaction time is 0.5~5h.

2. The Janus structure programmable temperature-controlled elastic material according to claim 1, characterized in that: The visible light transmittance of the first structural layer is 10%~50%.

3. The Janus structure programmable temperature-controlled elastic material according to claim 1, characterized in that: The thickness of the first structural layer is 1~6mm.

4. The Janus structure programmable temperature-controlled elastic material according to claim 1, characterized in that: The particle size of the photothermal absorption and conversion component is 1~1000µm.

5. The Janus structure programmable temperature-controlled elastic material according to claim 1, characterized in that: The thickness of the second structural layer is 1~6mm.

6. The Janus structure programmable temperature-controlled elastic material according to claim 1, characterized in that: The crosslinking agent is selected from propylene oxide, epichlorohydrin, glutaraldehyde, hexamethylene diisocyanate, 1,4-cyclohexane diisocyanate, trimethylhexamethylene diisocyanate, terephthalic diisocyanate, toluene diisocyanate, naphthalene 1,5-diisocyanate, 4,4'-methylenebis(phenyl isocyanate), 1,5-naphthalene diisocyanate, methylene diisocyanate, methyl-2,4-diisocyanate, diphenylmethane diisocyanate, isophenyl diisocyanate, 3,3-dimethyl-4,4'-diphenyl diisocyanate, isophorone diisocyanate, diisocyanate-based polyethylene glycol, ethyl(methyl)phenyl(methyl)diisocyanate, L-lysine diisocyanate, 3,3'-dichlorobiphenyl- Homopolymers of 4,4'-diisocyanate, 4-chloro-6-methyl-m-phenylene diisocyanate, 1-chloromethyl-2,4-diisocyanobenzene, 2,4-isocyanate-1-toluene, toluene-2,6-diisocyanate, m-phenylene diisocyanate, m-phenylene dimethyl isocyanate, 3,3′-dimethoxy-4,4′-biphenyl diisocyanate, 1,3-bis(1-isocyanate-1-methylethyl)benzene, 1,1',1"-methylenetris(4-isocyanate)benzene, and L-lysine triisocyanate, or any combination of two or more thereof.

7. The application of the Janus structure programmable temperature-controlled elastic material according to any one of claims 1-6 in the fields of passive solar heating, passive cooling, or infrared anti-counterfeiting.

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