A temperature-sensitive hydrogel with excellent water absorption performance, a preparation method and application thereof
A thermosensitive hydrogel was prepared by formulating acrylamide monomer, N,N-methylenebisacrylamide and ammonium persulfate solution and adding metal chloride, which solved the problems of poor water absorption and circulation performance and achieved a highly efficient solar heat dissipation effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- XI AN JIAOTONG UNIV
- Filing Date
- 2024-07-08
- Publication Date
- 2026-08-04
AI Technical Summary
Existing thermosensitive hydrogels have poor water absorption and poor cycle performance, which limits their application in the field of solar heat dissipation.
A hydrogel prepreg solution was prepared using acrylamide monomer, N,N-methylenebisacrylamide and ammonium persulfate solution, and metal chlorides such as lithium chloride, calcium chloride and magnesium chloride were added. Thermosensitive hydrogels were then prepared by drying.
The prepared hydrogel has excellent water absorption properties, with a water absorption rate of up to 76.1%. It also has high strength, good stability, and can be recycled multiple times, effectively improving the heat dissipation performance of solar panels.
Smart Images
Figure CN118878738B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of hydrogel preparation technology, specifically to a thermosensitive hydrogel with excellent water absorption properties, its preparation method, and its application. Background Technology
[0002] Thermosensitive hydrogels are a class of smart materials that exhibit sensitive responses to changes in environmental temperature and humidity. These hydrogels can absorb water and swell under low temperature and high humidity conditions, while losing water and shrinking under high temperature and low humidity conditions, thus exhibiting unique phase transition characteristics. This property gives thermosensitive hydrogels significant advantages in a variety of application fields.
[0003] This temperature-sensitive behavior is mainly attributed to the molecular structure and interactions within the hydrogel. At lower temperatures and higher humidity, water molecules easily permeate and form hydrogen bonds with the hydrophilic groups inside the hydrogel, causing the gel to absorb water and swell. Conversely, when the temperature rises and humidity decreases, the hydrogen bonds break, water molecules escape from the gel, and the gel volume shrinks.
[0004] This property makes thermosensitive hydrogels outstanding in many practical applications. In agriculture, thermosensitive hydrogels can act as soil moisturizers, absorbing and storing water in low-temperature, high-humidity conditions and releasing water in high-temperature, dry conditions, thereby effectively regulating soil moisture and promoting plant growth. In the medical and biotechnology fields, this hydrogel can be used to develop intelligent drug delivery systems, absorbing and storing drugs at lower temperatures in the human body and releasing them at higher temperatures to reach the target tissue, enabling precise treatment. Furthermore, thermosensitive hydrogels also show broad application prospects in smart textiles, flexible electronic devices, and environmental sensors.
[0005] Studies have shown that, due to the highest latent heat in water, thermosensitive hydrogels are expected to be used in the heat dissipation of solar cell backsheets. However, the limited water absorption capacity, poor reversibility of phase transition, and limited recyclability of existing hydrogels have hindered their application in the field of solar heat dissipation. Summary of the Invention
[0006] To address the problems of poor water absorption and poor cycle performance of existing temperature-sensitive hydrogels, this invention provides a temperature-sensitive hydrogel with excellent water absorption properties, its preparation method, and its application.
[0007] To achieve the above objectives, the present invention employs the following technical solution:
[0008] This invention provides a method for preparing a thermosensitive hydrogel with excellent water absorption properties, comprising:
[0009] Prepare acrylamide monomer solution, N,N-methylenebisacrylamide solution and ammonium persulfate solution respectively;
[0010] Add N,N-methylenebisacrylamide solution, ammonium persulfate solution and metal chloride to acrylamide monomer solution to obtain hydrogel prepreg solution;
[0011] The hydrogel prepreg solution was dried to obtain a thermosensitive hydrogel.
[0012] Furthermore, the metal chloride is one or more of lithium chloride, calcium chloride, and magnesium chloride.
[0013] Furthermore, the concentration of the acrylamide monomer solution is 300–400 mg / mL.
[0014] Furthermore, the concentration of the N,N-methylenebisacrylamide solution is 3–4 mg / mL.
[0015] Furthermore, the concentration of the ammonium persulfate solution is 45–55 mg / mL.
[0016] Furthermore, the volume ratio of the acrylamide monomer solution, N,N-methylenebisacrylamide solution, and ammonium persulfate solution is 500:(38-42):(9-11).
[0017] Furthermore, the concentration of metal chloride in the hydrogel prepreg solution is 90–370 mg / mL.
[0018] Furthermore, the drying temperature of the hydrogel preform solution is 50℃~70℃.
[0019] This invention provides a thermosensitive hydrogel with excellent water absorption properties, prepared using the method described above.
[0020] The above-mentioned thermosensitive hydrogels with excellent water absorption properties are used in the field of solar heat dissipation.
[0021] Compared with the prior art, the present invention has the following beneficial effects:
[0022] This invention discloses a method for preparing a thermosensitive hydrogel with excellent water absorption properties. The method involves preparing an acrylamide monomer solution, an N,N-methylenebisacrylamide solution, and an ammonium persulfate solution, respectively. The N,N-methylenebisacrylamide solution, ammonium persulfate solution, and a metal chloride are then added to the acrylamide monomer solution, followed by drying to obtain the thermosensitive hydrogel. The addition of the metal chloride enhances the water absorption capacity of the hydrogel by allowing the hydrogen bonds formed between the amino groups on the polyacrylamide side chains and water molecules to interact with the metal ions. Furthermore, the prepared hydrogel exhibits high strength and good stability, maintaining excellent water absorption and loss characteristics even after multiple cycles. The preparation method is simple, the reaction is mild, and requires no heating or special reaction conditions. It is low-polluting, low-cost, and suitable for large-scale industrialization.
[0023] The metal chloride is lithium chloride, because Li + Compared to other metal ions, it is smaller in size, and the gaps between polyacrylamide chains are smaller, which allows it to absorb more water molecules, thereby further improving the water absorption of the hydrogel.
[0024] This invention also provides a thermosensitive hydrogel with excellent water absorption properties. Prepared using the above method, this hydrogel exhibits excellent water absorption, reaching 76.1%. The force-displacement relationship before failure is essentially linear, with an elastic modulus of 13.17 kPa, a maximum tensile strength of 161.18 kPa, and an elongation at break of 1101%, demonstrating excellent mechanical properties. Cyclic water absorption and loss tests showed that after 15 days of intensive water absorption and loss cycling, the hydrogel still maintains its original water absorption characteristics, indicating excellent cycling performance.
[0025] This invention also provides the application of the temperature-sensitive hydrogel with excellent water absorption properties, as described above, in the field of solar heat dissipation. This enables continuous and effective heat dissipation from solar panels, thereby improving the photoelectric conversion efficiency of the solar panels. Attached Figure Description
[0026] Figure 1 This is a schematic diagram of the preparation method of a thermosensitive hydrogel with excellent water absorption properties according to the present invention.
[0027] Figure 2 A comparison chart of the dry weight and water-saturated mass of the hydrogel prepared in the embodiments of the present invention.
[0028] Figure 3 A comparison chart showing the percentage of water absorption of the hydrogels prepared in the embodiments of the present invention.
[0029] Figure 4 A comparison diagram of the changes in the water absorption and loss states of the hydrogel prepared in the embodiments of the present invention.
[0030] Figure 5 The figure shows the strength test results of the hydrogel prepared according to an embodiment of the present invention.
[0031] Figure 6 Temperature variation curves of the hydrogel prepared for the embodiments of the present invention in the heat dissipation application of solar panels. Detailed Implementation
[0032] To enable those skilled in the art to understand the features and effects of the present invention, the terms and expressions used in the specification and claims are explained and defined in general below. Unless otherwise specified, all technical and scientific terms used herein have the ordinary meaning understood by those skilled in the art regarding the present invention, and in case of conflict, the definitions in this specification shall prevail.
[0033] The theories or mechanisms described and disclosed herein, whether right or wrong, should not in any way limit the scope of the invention, that is, the contents of the invention can be implemented without being limited by any particular theory or mechanism.
[0034] In this document, all features defined by numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values (including integers and fractions) within those ranges.
[0035] In this article, unless otherwise specified, “contains,” “includes,” “containing,” “has,” or similar terms cover the meanings of “composed of” and “mainly composed of,” for example, “A contains a” covers the meanings of “A contains a and others” and “A contains only a.”
[0036] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.
[0037] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.
[0038] The following examples use instruments and equipment conventional in the art. Experimental methods in the following examples, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. All raw materials used in the following examples are conventional commercially available products with specifications conventional in the art. In this specification and the following examples, unless otherwise specified, "%" refers to weight percentage, "parts" refers to parts by weight, and "ratio" refers to weight proportion.
[0039] The present invention will be further described in detail below with reference to specific embodiments. These descriptions are for explanation purposes only and are not intended to limit the scope of the invention.
[0040] See Figure 1 This invention discloses a method for preparing a temperature-sensitive hydrogel with excellent water absorption properties, comprising:
[0041] S1: Prepare acrylamide monomer solution, N,N-methylenebisacrylamide solution, and ammonium persulfate solution respectively; wherein the metal chloride is one or more of lithium chloride, magnesium chloride, and calcium chloride; the concentration of the acrylamide monomer solution is 300-400 mg / mL; the concentration of the N,N-methylenebisacrylamide solution is 3-4 mg / mL; the concentration of the ammonium persulfate solution is 45-55 mg / mL; the solvent for the acrylamide monomer solution, N,N-methylenebisacrylamide solution, and ammonium persulfate solution is water.
[0042] S2: Add N,N-methylenebisacrylamide solution, ammonium persulfate solution and metal chloride to the acrylamide monomer solution to obtain a hydrogel prepreg solution; wherein, the volume ratio of the acrylamide monomer solution, N,N-methylenebisacrylamide solution and ammonium persulfate solution is 500:(38-42):(9-11); the concentration of metal chloride in the hydrogel prepreg solution is 90-370 mg / mL; after adding the metal chloride, the solution is sonicated to mix it evenly.
[0043] S3: Dry the hydrogel prepreg solution to obtain a thermosensitive hydrogel. The drying temperature is 50℃~70℃ and the drying time is 2~3h.
[0044] Example 1
[0045] Weigh 1.78 g of acrylamide (AM) monomer and place it in 5 mL of deionized water. Sonicate for 1 min to fully dissolve the AM monomer to obtain an acrylamide monomer solution. Weigh 0.038 g of N,N-methylenebisacrylamide (MBA) and dissolve it in 10 mL of deionized water to obtain an N,N-methylenebisacrylamide solution. Weigh 0.5 g of ammonium persulfate (APS) and dissolve it in 10 mL of deionized water to obtain an ammonium persulfate solution.
[0046] Weigh 500 mg of anhydrous lithium chloride and add it to an acrylamide solution. Stir the solution with ultrasound for 5 min to ensure complete dissolution. Then, rapidly add 0.4 mL of N,N-methylenebisacrylamide solution and 0.105 mL of ammonium persulfate solution dropwise. Transfer the mixed solution to an ultrasonic machine and sonicate continuously for 2 min to ensure homogeneity. The resulting hydrogel prepreg solution is then dried in a 60°C oven for 3 h to obtain a thermosensitive hydrogel.
[0047] Example 2
[0048] Weigh 1.78 g of acrylamide (AM) monomer and place it in 5 mL of deionized water. Sonicate for 1 min to fully dissolve the AM monomer to obtain an acrylamide monomer solution. Weigh 0.038 g of N,N-methylenebisacrylamide (MBA) and dissolve it in 10 mL of deionized water to obtain an N,N-methylenebisacrylamide solution. Weigh 0.5 g of ammonium persulfate (APS) and dissolve it in 10 mL of deionized water to obtain an ammonium persulfate solution.
[0049] Weigh 500 mg of anhydrous calcium chloride and add it to an acrylamide solution. Stir the solution with ultrasound for 5 min to ensure complete dissolution. Then, rapidly add 0.4 mL of N,N-methylenebisacrylamide solution and 0.105 mL of ammonium persulfate solution dropwise. Transfer the mixed solution to an ultrasonic machine and sonicate continuously for 2 min to ensure homogeneity. The resulting hydrogel prepreg solution is then dried in a 60°C oven for 3 h to obtain a thermosensitive hydrogel.
[0050] Example 3
[0051] Weigh 1.78 g of acrylamide (AM) monomer and place it in 5 mL of deionized water. Sonicate for 1 min to fully dissolve the AM monomer to obtain an acrylamide monomer solution. Weigh 0.038 g of N,N-methylenebisacrylamide (MBA) and dissolve it in 10 mL of deionized water to obtain an N,N-methylenebisacrylamide solution. Weigh 0.5 g of ammonium persulfate (APS) and dissolve it in 10 mL of deionized water to obtain an ammonium persulfate solution.
[0052] Weigh 1000 mg of anhydrous lithium chloride and add it to an acrylamide solution. Stir the solution with sonication for 5 min to ensure complete dissolution. Then, rapidly add 0.4 mL of N,N-methylenebisacrylamide solution and 0.105 mL of ammonium persulfate solution dropwise. Transfer the mixed solution to an ultrasonic machine and sonicate continuously for 2 min to ensure homogeneity. The resulting hydrogel prepreg solution is then dried in a 60°C oven for 3 h to obtain a thermosensitive hydrogel.
[0053] Example 4
[0054] Weigh 1.78 g of acrylamide (AM) monomer and place it in 5 mL of deionized water. Sonicate for 1 min to fully dissolve the AM monomer to obtain an acrylamide monomer solution. Weigh 0.038 g of N,N-methylenebisacrylamide (MBA) and dissolve it in 10 mL of deionized water to obtain an N,N-methylenebisacrylamide solution. Weigh 0.5 g of ammonium persulfate (APS) and dissolve it in 10 mL of deionized water to obtain an ammonium persulfate solution.
[0055] Weigh 1500 mg of anhydrous lithium chloride and add it to an acrylamide solution. Stir the solution with ultrasound for 5 min to ensure complete dissolution. Then, rapidly add 0.4 mL of N,N-methylenebisacrylamide solution and 0.105 mL of ammonium persulfate solution dropwise. Transfer the mixed solution to an ultrasonic machine and sonicate continuously for 2 min to ensure homogeneity. The resulting hydrogel prepreg solution is then dried in a 60°C oven for 3 h to obtain a thermosensitive hydrogel.
[0056] Example 5
[0057] Weigh 1.78 g of acrylamide (AM) monomer and place it in 5 mL of deionized water. Sonicate for 1 min to fully dissolve the AM monomer to obtain an acrylamide monomer solution. Weigh 0.038 g of N,N-methylenebisacrylamide (MBA) and dissolve it in 10 mL of deionized water to obtain an N,N-methylenebisacrylamide solution. Weigh 0.5 g of ammonium persulfate (APS) and dissolve it in 10 mL of deionized water to obtain an ammonium persulfate solution.
[0058] Weigh 1000 mg of anhydrous calcium chloride and add it to an acrylamide solution. Sonicate for 5 min to dissolve it completely. Then, add 0.4 mL of N,N-methylenebisacrylamide solution and 0.105 mL of ammonium persulfate solution dropwise. Transfer the mixed solution to an ultrasonic machine and sonicate continuously for 2 min to mix the solution evenly. The hydrogel prepreg solution is then placed in a 60°C oven and dried for 3 h to obtain a thermosensitive hydrogel.
[0059] Example 6
[0060] Weigh 1.78 g of acrylamide (AM) monomer and place it in 5 mL of deionized water. Sonicate for 1 min to fully dissolve the AM monomer to obtain an acrylamide monomer solution. Weigh 0.038 g of N,N-methylenebisacrylamide (MBA) and dissolve it in 10 mL of deionized water to obtain an N,N-methylenebisacrylamide solution. Weigh 0.5 g of ammonium persulfate (APS) and dissolve it in 10 mL of deionized water to obtain an ammonium persulfate solution.
[0061] Weigh 1500 mg of anhydrous calcium chloride and add it to an acrylamide solution. Stir the solution with ultrasound for 5 min to ensure complete dissolution. Then, add 0.4 mL of N,N-methylenebisacrylamide solution and 0.105 mL of ammonium persulfate solution dropwise. Transfer the mixed solution to an ultrasound machine and sonicate continuously for 2 min to ensure homogeneity. The resulting hydrogel prepreg solution is then dried in a 60°C oven for 3 h to obtain a thermosensitive hydrogel.
[0062] Example 7
[0063] Weigh 1.78 g of acrylamide (AM) monomer and place it in 5 mL of deionized water. Sonicate for 1 min to fully dissolve the AM monomer to obtain an acrylamide monomer solution. Weigh 0.038 g of N,N-methylenebisacrylamide (MBA) and dissolve it in 10 mL of deionized water to obtain an N,N-methylenebisacrylamide solution. Weigh 0.5 g of ammonium persulfate (APS) and dissolve it in 10 mL of deionized water to obtain an ammonium persulfate solution.
[0064] Weigh 1500 mg of anhydrous magnesium chloride and add it to an acrylamide solution. Stir the solution with ultrasound for 5 min to ensure complete dissolution. Then, rapidly add 0.4 mL of N,N-methylenebisacrylamide solution and 0.105 mL of ammonium persulfate solution dropwise. Transfer the mixed solution to an ultrasonic machine and sonicate continuously for 2 min to ensure homogeneity. The resulting hydrogel prepreg solution is then dried in a 60°C oven for 3 h to obtain a thermosensitive hydrogel.
[0065] Example 8
[0066] Weigh 1.78 g of acrylamide (AM) monomer and place it in 5 mL of deionized water. Sonicate for 1 min to fully dissolve the AM monomer to obtain an acrylamide monomer solution. Weigh 0.038 g of N,N-methylenebisacrylamide (MBA) and dissolve it in 10 mL of deionized water to obtain an N,N-methylenebisacrylamide solution. Weigh 0.5 g of ammonium persulfate (APS) and dissolve it in 10 mL of deionized water to obtain an ammonium persulfate solution.
[0067] Weigh 1500 mg of polyacrylamide-lithium chloride (PAM-LiCl) and add it to an acrylamide solution. Stir the mixture with ultrasound for 5 min to ensure complete dissolution. Then, rapidly add 0.4 mL of N,N-methylenebisacrylamide solution and 0.105 mL of ammonium persulfate solution dropwise. Transfer the mixed solution to an ultrasonic machine and sonicate continuously for 2 min to ensure homogeneity. The resulting hydrogel prepreg solution is then dried in a 60°C oven for 3 h to obtain a thermosensitive hydrogel.
[0068] Example 9
[0069] Weigh 1.5 g of acrylamide (AM) monomer and place it in 5 mL of deionized water. Sonicate for 1 min to fully dissolve the AM monomer to obtain an acrylamide monomer solution. Weigh 0.03 g of N,N-methylenebisacrylamide (MBA) and dissolve it in 10 mL of deionized water to obtain an N,N-methylenebisacrylamide solution. Weigh 0.45 g of ammonium persulfate (APS) and dissolve it in 10 mL of deionized water to obtain an ammonium persulfate solution.
[0070] Weigh 500 mg of lithium chloride and add it to an acrylamide solution. Stir the solution with ultrasound for 5 min to ensure complete dissolution. Then, add 0.38 mL of N,N-methylenebisacrylamide solution and 0.9 mL of ammonium persulfate solution dropwise. Transfer the mixed solution to an ultrasound machine and sonicate continuously for 2 min to ensure homogeneity. The resulting hydrogel prepreg solution is then dried in a 65°C oven for 3 h to obtain a thermosensitive hydrogel.
[0071] Example 10
[0072] Weigh 1.5 g of acrylamide (AM) monomer and place it in 5 mL of deionized water. Sonicate for 1 min to fully dissolve the AM monomer to obtain an acrylamide monomer solution. Weigh 0.03 g of N,N-methylenebisacrylamide (MBA) and dissolve it in 10 mL of deionized water to obtain an N,N-methylenebisacrylamide solution. Weigh 0.45 g of ammonium persulfate (APS) and dissolve it in 10 mL of deionized water to obtain an ammonium persulfate solution.
[0073] Weigh 500 mg of lithium chloride and add it to an acrylamide solution. Stir the solution with ultrasound for 5 min to ensure complete dissolution. Then, add 0.38 mL of N,N-methylenebisacrylamide solution and 0.9 mL of ammonium persulfate solution dropwise. Transfer the mixed solution to an ultrasound machine and sonicate continuously for 2 min to ensure homogeneity. The resulting hydrogel prepreg solution is then dried in a 65°C oven for 3 h to obtain a thermosensitive hydrogel.
[0074] Example 11
[0075] Weigh 2g of acrylamide (AM) monomer and place it in 5mL of deionized water. Sonicate for 1min to fully dissolve the AM monomer to obtain an acrylamide monomer solution. Weigh 0.04g of N,N-methylenebisacrylamide (MBA) and dissolve it in 10mL of deionized water to obtain an N,N-methylenebisacrylamide solution. Weigh 0.55g of ammonium persulfate (APS) and dissolve it in 10mL of deionized water to obtain an ammonium persulfate solution.
[0076] Weigh 2000 mg of lithium chloride and add it to an acrylamide solution. Stir the solution with ultrasound for 5 min to ensure complete dissolution. Then, rapidly add 0.42 mL of N,N-methylenebisacrylamide solution and 1.1 mL of ammonium persulfate solution dropwise. Transfer the mixed solution to an ultrasound machine and sonicate continuously for 2 min to ensure homogeneity. The resulting hydrogel prepreg solution is then dried in a 65°C oven for 3 h to obtain a thermosensitive hydrogel.
[0077] Example 12
[0078] Weigh 1.7 g of acrylamide (AM) monomer and place it in 5 mL of deionized water. Sonicate for 1 min to fully dissolve the AM monomer to obtain an acrylamide monomer solution. Weigh 0.035 g of N,N-methylenebisacrylamide (MBA) and dissolve it in 10 mL of deionized water to obtain an N,N-methylenebisacrylamide solution. Weigh 0.43 g of ammonium persulfate (APS) and dissolve it in 10 mL of deionized water to obtain an ammonium persulfate solution.
[0079] Weigh 1700 mg of lithium chloride and add it to an acrylamide solution. Stir the mixture with ultrasound for 5 min to ensure complete dissolution. Then, rapidly add 0.4 mL of N,N-methylenebisacrylamide solution and 1 mL of ammonium persulfate solution dropwise. Transfer the mixed solution to an ultrasound machine and sonicate continuously for 2 min to ensure homogeneity. This yields a pre-prepared hydrogel solution. Dry the pre-prepared hydrogel solution in a 65°C oven for 3 h to obtain a thermosensitive hydrogel.
[0080] See Figure 2 and Figure 3 The water absorption performance of the thermosensitive hydrogels prepared in Examples 1-8 was tested. A constant temperature and humidity chamber was used to simulate the water absorption environment of the hydrogels, with the temperature set at 25℃ and the humidity at 80%. After 12 hours of initial screening, it was found that the hydrogels with added lithium chloride had better water absorption performance. The hydrogels with 500mg, 1000mg, and 1500mg of lithium chloride absorbed 1.05g, 2.32g, and 3.38g of water, respectively, with relative water absorption rates of 38.1%, 64.8%, and 76.1%, indicating that the hydrogels had better water absorption. Simultaneously, a 3.5wt% NaCl solution was prepared to simulate the sea surface environment. By testing the changes in swelling of the hydrogels immersed in simulated seawater and deionized water, it was found that the hydrogels were not affected by NaCl. + and Cl - It generates a repulsive effect, and its absorption efficiency for seawater is basically the same as that for deionized water. Moreover, its saturation point for exchanging water with the outside world is higher than that of deionized water, so it can be used for heat dissipation of marine solar photovoltaic panels.
[0081] See Figure 4 To verify the hydrogel's ability to maintain moisture balance and its cyclical properties, the hydrogel was completely dried and then subjected to water absorption at 25°C and 50% humidity for 12 hours and water loss at 55°C and 20% humidity for 6 hours. The mass change was recorded, and the experiment lasted for 15 days, with a total of 15 sets of data recorded. As shown in the figure, after 15 days of cyclic performance testing, the hydrogel can still maintain its original water absorption and loss characteristics, demonstrating excellent recyclability.
[0082] See Figure 5The strength of the hydrogel prepared in Example 4 was tested. The results showed that the force-displacement relationship before the failure of the thermosensitive hydrogel was basically linear, the elastic modulus was 13.17 kPa, and the maximum tensile strength was 161.18 kPa, which proved that the hydrogel had high strength and good stability. The elongation at break was 1101%, which proved that the hydrogel had good plasticity.
[0083] A thermosensitive hydrogel with excellent water absorption properties was prepared using the method described above. The force-displacement relationship before failure of this thermosensitive hydrogel is essentially linear, with an elastic modulus of 13.17 kPa, a maximum tensile strength of 161.18 kPa, and an elongation at break of 1101%, exhibiting excellent mechanical properties. Cyclic water absorption and loss tests showed that after 15 days of intensive water absorption and loss cycling, the hydrogel still maintained its original water absorption characteristics, demonstrating excellent cycling performance.
[0084] The aforementioned temperature-sensitive hydrogels with excellent water absorption properties are used in the field of solar heat dissipation. This enables continuous and effective heat dissipation from solar panels, thereby improving the photoelectric conversion efficiency of the solar panels.
[0085] The hydrogel prepared in Example 1 was used to test its photovoltaic management effect. In the experiment, the photovoltaic panel was tightly bonded to the hydrogel under gravity, and both were stably supported by a supporting structure. Three industrial thermocouples were placed at equal intervals on the upper and lower surfaces of the photovoltaic panel to detect the surface temperature distribution. The average temperature was taken as the photovoltaic panel temperature. The solar irradiance received by the photovoltaic panel was measured using an SM206 solar power meter. The results are as follows: Figure 6 As shown, under the same light irradiance, the temperature of the photovoltaic panel with hydrogel is significantly lower than that without hydrogel, and the temperature of the photovoltaic panel can still be controlled within its normal operating temperature range under higher light irradiance conditions, proving the significant effect of the temperature-sensitive hydrogel on the thermal management of the photovoltaic panel.
[0086] The above description is merely a preferred embodiment of the present invention and is not intended to limit the technical solution of the present invention in any way. Those skilled in the art should understand that, without departing from the spirit and principles of the present invention, the technical solution can be modified and replaced in several simple ways, and these modifications and replacements are all within the scope of protection covered by the claims.
Claims
1. A method for producing a temperature-sensitive hydrogel having excellent water absorption, characterized by, include: Acrylamide monomer solution, N,N-methylenebisacrylamide solution, and ammonium persulfate solution were prepared separately as follows: 1.78 g of acrylamide monomer was weighed and placed in 5 mL of deionized water, and sonicated for 1 min to fully dissolve the AM monomer, thus obtaining an acrylamide monomer solution; 0.038 g of N,N-methylenebisacrylamide was weighed and dissolved in 10 mL of deionized water, thus obtaining an N,N-methylenebisacrylamide solution; 0.5 g of ammonium persulfate was weighed and dissolved in 10 mL of deionized water, thus obtaining an ammonium persulfate solution. Adding N,N-methylenebisacrylamide solution, ammonium persulfate solution, and metal chloride to an acrylamide monomer solution yields a pre-hydrogel solution, specifically: Weigh 1500 mg of anhydrous lithium chloride and add it to the acrylamide monomer solution. Stir the mixture with ultrasound for 5 min to ensure complete dissolution. Then, add 0.4 mL of N,N-methylenebisacrylamide solution and 0.105 mL of ammonium persulfate solution dropwise. Transfer the mixed solution to an ultrasound machine and sonicate continuously for 2 min to ensure homogeneity and obtain the hydrogel prepreg solution. The hydrogel prepreg solution was dried to obtain a thermosensitive hydrogel. Specifically, the hydrogel prepreg solution was placed in a 60°C oven and dried for 3 hours to obtain a thermosensitive hydrogel.
2. A thermosensitive hydrogel with excellent water absorption properties, characterized in that, Prepared using the method of claim 1.
3. The application of the thermosensitive hydrogel with excellent water absorption properties as described in claim 2 in the field of solar heat dissipation.