Phase change energy storage material and preparation method thereof
By introducing porous framework materials and cross-linked components into phase change materials to form a solid network, the phase separation problem of phase change energy storage materials is solved, and the stability and mechanical properties of the materials are improved. This makes the materials suitable for applications such as logistics cold chain, building envelope, and industrial insulation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- THERO NEW MATERIAL TECH CO LTD
- Filing Date
- 2025-12-30
- Publication Date
- 2026-05-29
AI Technical Summary
Existing phase change energy storage materials are prone to phase separation after multiple cycles, resulting in a short service life.
By introducing porous framework materials into phase change materials and using the first and second crosslinking components to form a continuous solid network to encapsulate the phase change materials, a porous phase change energy storage material is formed, which reduces the probability of phase separation and improves mechanical properties.
This has improved the stability and mechanical properties of phase change materials, extended their service life, and made them suitable for applications such as cold chain logistics, building envelope, and industrial insulation.
Smart Images
Figure CN122104154A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of phase change energy storage materials technology, specifically to a phase change energy storage material and its preparation method. Background Technology
[0002] With the acceleration of global energy transition and the popularization of the low-carbon economy, energy storage technology is becoming increasingly important as a key solution to the intermittency and instability of new energy sources. Phase change energy storage is one of the research hotspots in the field of energy storage technology. It has a series of advantages such as high energy density, good temperature uniformity in the phase change process, high safety, and reusability. It is commonly used in applications such as logistics cold chain, aerospace, power plant peak shaving and valley filling, and the development of home appliances, as well as for the storage of various energy sources such as electricity, solar energy, wind energy, ocean energy, and industrial waste heat.
[0003] The phase change energy storage materials provided in related technologies are prone to phase separation after multiple cycles, resulting in a short service life. Summary of the Invention
[0004] The embodiments of the present invention provide a phase change energy storage material that can improve the technical problem of phase separation that easily occurs in phase change materials in related technologies.
[0005] In a first aspect, embodiments of the present invention provide a phase change energy storage material, which, by weight, comprises 70-90 parts of phase change material, 2-20 parts of a first crosslinking component, 0-2 parts of a second crosslinking component, 0.01-0.08 parts of initiator, 0.01-1 parts of nucleating agent, 0.01-6 parts of surfactant, and 0.01-10 parts of porous framework material; Wherein, the first crosslinking component and the second crosslinking component are used to crosslink and form a continuous solid network; or, the first crosslinking component crosslinks to form a continuous solid network.
[0006] In some embodiments, the porous skeleton material includes one or more of polyurethane foam board, rock wool board, hollow plastic board, nano-aerogel felt and nano-aerogel board.
[0007] In some embodiments, the first crosslinking component comprises monomers and / or polymers, and the second crosslinking component comprises a crosslinking agent; wherein... The monomers include one or more of acrylamide, N-isopropylacrylamide, divinylbenzene, acrylic acid, N-hydroxyacrylamide, epoxy acrylic acid, hydroxyethyl acrylate, acrylate amine, cycloolefin monomers, and vinylpyrrolidone; and / or, The polymer includes one or more of polyvinyl alcohol, vinyl polyvinyl alcohol, gelatin, sodium alginate, and chitosan; and / or, The crosslinking agent includes one or more of N,N'-methylenebisacrylamide, dicyandiamide, tetrafluoroethylene, glutaraldehyde, trifluorochlorocyanuric acid, dimethyl glutarate, isocyanate, dimethylnitrosamine, iron ions, calcium ions, and trivalent aluminum ions.
[0008] In some embodiments, the phase change material comprises one or more of hydrated salts, inorganic salts, and organic solutions; and / or, The initiator includes one or more of persulfate, hydrogen peroxide, sodium perchlorate, sulfite, dichloroperoxide, tetramethylethylenediamine, benzophenone, benzophenone, azo compounds, and benzoyl peroxide; and / or, Nucleating agents include one or more of polyethylene, talc, mica, borax, and phosphates; and / or, The surfactant includes one or more of sodium dodecyl sulfate, ammonium dodecyl sulfate, sodium alkylbenzene sulfonate, fatty acid salts, hexadecyltrimethylammonium chloride, benzalkonium chloride, polyethylene ether, fatty alcohol ether, polyoxyethylene allyl ether, lauroylamine, and betaine.
[0009] Secondly, embodiments of the present invention provide a method for preparing the phase change energy storage material as described in any of the foregoing embodiments, comprising: The phase change material, the first crosslinking component, the second crosslinking component, the initiator, the nucleating agent, and the surfactant are added to the reaction vessel and stirred until dissolved into a solution or colloid. The solution or colloid is placed in a container, the porous framework material is placed into the solution or colloid, and then vacuum sealed. This allows the material to complete gelation.
[0010] In some embodiments, the gelation of the material includes: The container is kept warm and moist for 5 to 24 hours in an environment with a temperature range of 30 to 90°C and a humidity range of 20 to 80% until the material gels.
[0011] In some embodiments, stirring until dissolved into a solution or colloid includes: The solution or colloid was stirred at a speed of 200 rpm to 500 rpm for 30 min to 120 min.
[0012] In some embodiments, the gelation of the material includes: Repeated freezing and thawing of the container causes the material to gel.
[0013] In some embodiments, the gelation of the material includes: Let the container stand for 30 to 120 minutes; The container is kept warm and moist at an temperature of 30℃ to 60℃ to allow the material to gel.
[0014] In some embodiments, the gelation of the material includes: Let the container stand for 30 to 120 minutes; Add a photoinitiator to gel the material.
[0015] The beneficial effects of the embodiments of the present invention are as follows: In the embodiments of the present invention, the porous framework material with a porous structure can adsorb the phase change material, so that after the monomer and the crosslinking agent complete the crosslinking reaction, the phase change material completes gelation inside the porous framework material, completely filling the voids inside the porous framework material. This reduces the probability of phase separation and also improves the mechanical properties of the material, such as compressive strength, shear strength, and dimensional stability. This allows the phase change energy storage material in this application to be widely used in applications such as logistics cold chain, building envelope, and industrial insulation. Attached Figure Description
[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0017] Figure 1 This is a schematic diagram of the crosslinking process between the monomer and the crosslinking agent provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the phase change energy storage material provided in the embodiments of the present invention; Figure 3 This is a schematic diagram illustrating the manufacturing process of the phase change energy storage material provided in an embodiment of the present invention; Figure 4 This is a flowchart of a method for preparing phase change energy storage materials according to an embodiment of the present invention; Figure 5 The graph shows the DSC test results of the phase change energy storage material prepared in Comparative Example 1. Figure 6 This is a DSC test result graph of the phase change energy storage material prepared in Example 1; Figure 7 This is a DSC test result graph of the phase change energy storage material prepared in Example 1 after 200 phase change cycles; Figure 8 This is a DSC test result graph of the phase change energy storage material prepared in Example 1 after 500 phase change cycles; Figure 9 This is a DSC test result graph of the phase change energy storage material prepared in Example 2; Figure 10 This is a DSC test result graph of the phase change energy storage material prepared in Example 3; Figure 11 This is a DSC test result diagram of the phase change energy storage material prepared in Example 4; Figure 12 This is a DSC test result graph of the phase change energy storage material prepared in Example 5; Figure 13 This is a graph showing the DSC test results of the phase change energy storage material prepared in Comparative Example 2. Detailed Implementation
[0018] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.
[0019] To enable those skilled in the art to better understand the solutions of this application, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.
[0020] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0021] Reference Figures 1 to 3The first aspect of this invention provides a phase change energy storage material, comprising, by weight, 70-90 parts of phase change material, 2-20 parts of a first crosslinking component, 0-2 parts of a second crosslinking component, 0.01-0.08 parts of an initiator, 0.01-1 parts of a nucleating agent, 0.01-6 parts of a surfactant, and 0.01-10 parts of a porous framework material. The first and second crosslinking components are used to crosslink and form a continuous solid network; or, the first crosslinking component crosslinks to form a continuous solid network. The shape and size of the porous framework material can be set as needed, and this embodiment of the invention does not limit this.
[0022] In this embodiment of the invention, a porous framework material with a porous structure can adsorb phase change materials, so that after the first crosslinking component and the second crosslinking component complete the crosslinking reaction, the phase change material completes gelation inside the porous framework material, completely filling the voids inside the porous framework material. This reduces the probability of phase separation and also improves the mechanical properties of the material, such as compressive strength, shear strength, and dimensional stability. This allows the phase change energy storage material in this application to be widely used in applications such as logistics cold chain, building envelope, and industrial insulation.
[0023] In one embodiment, the porous skeleton material includes one or more of polyurethane foam board, rock wool board, hollow plastic board, nano-aerogel felt and nano-aerogel board.
[0024] Preferably, hollow plastic sheets can be used as the porous skeleton material. Because hollow plastic sheets have good pressure resistance and structural stability, the phase change material enters the voids in the hollow plastic sheet in liquid form. Even if the phase change material cross-links and forms, it will not significantly affect the properties of the hollow plastic sheet itself. Polyurethane foam boards can also be used as the porous skeleton material, as they possess good flexibility and deformation recovery properties.
[0025] In one embodiment, the first crosslinking component comprises monomers and / or polymers, and the second crosslinking component comprises a crosslinking agent; wherein the monomers comprise one or more of acrylamide, N-isopropylacrylamide, divinylbenzene, acrylic acid, N-hydroxyacrylamide, epoxy acrylic acid, hydroxyethyl acrylate, acrylate amine, cycloolefin monomers, and vinylpyrrolidone; and / or the polymers comprise one or more of polyvinyl alcohol, vinyl polyvinyl alcohol, gelatin, sodium alginate, and chitosan; and / or the crosslinking agents comprise one or more of N,N'-methylenebisacrylamide, dicyandiamide, tetrafluoroethylene, glutaraldehyde, trifluorochlorocyanuric acid, dimethyl glutarate, isocyanate, dimethylnitrosamine, iron ions, calcium ions, and trivalent aluminum ions.
[0026] In one embodiment, the phase change material comprises one or more of hydrated salts, inorganic salts, and organic solutions; and / or, the initiator comprises one or more of persulfate, hydrogen peroxide, sodium perchlorate, sulfite, dichloroperoxide, tetramethylethylenediamine, benzophenone, benzophenone, azo compounds, and benzoyl peroxide; and / or, the nucleating agent comprises one or more of polyethylene, talc, mica, borax, and phosphates; and / or, the surfactant comprises one or more of sodium dodecyl sulfate, ammonium dodecyl sulfate, sodium alkylbenzene sulfonate, fatty acid salts, hexadecyltrimethylammonium chloride, benzalkonium chloride, polyethylene ether, fatty alcohol ether, polyoxyethylene allyl ether, lauroylamine, and betaine.
[0027] It should be noted that in this application, "and / or" describes the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / ", unless otherwise specified, generally indicates that the related objects before and after it are in an "or" relationship.
[0028] Secondly, referring to Figure 4 The present invention provides a first method for preparing the aforementioned phase change energy storage material, comprising: S100: Add the phase change material, the first crosslinking component, the second crosslinking component, the initiator, the nucleating agent, and the surfactant to the reactor and stir until dissolved into a solution or colloid; S200: Place the solution or colloid in a container, place the porous framework material into the solution or colloid, and vacuum seal; S300: Enables the material to gel.
[0029] In this embodiment of the invention, the first crosslinking component and the second crosslinking component are crosslinked through covalent bonds, ionic bonds, or hydrogen bonds to form a continuous solid network. The phase change material is encapsulated in the solid network, causing the phase change energy storage material in this application to lose its fluidity as a whole, thus achieving a solid-solid phase change effect. That is, energy storage is achieved only through the solid-liquid phase change of the internal phase change material, while the external solid network remains solid. This ensures that the phase change energy storage material in this application always presents a solid form, thereby reducing the probability of leakage of the phase change material during the phase change process and ensuring the stability of the phase change energy storage material.
[0030] The phase change material, the first crosslinking component, the second crosslinking component, the initiator, the nucleating agent, and the surfactant can be added to the container in sequence. After the previous component is completely dissolved into a solution or colloid, the next component is added. Alternatively, the second crosslinking component, the initiator, and the nucleating agent can be added simultaneously.
[0031] In step S200, the porous framework material is placed in a solution or colloid, allowing it to adsorb the phase change material. After the first and second crosslinking components complete their crosslinking reaction, the phase change material gels within the porous framework, completely filling the internal pores. This further reduces the probability of phase separation and improves the material's compressive strength, shear strength, dimensional stability, and other mechanical properties. This makes the phase change energy storage material of this application widely applicable in logistics cold chain, building envelope, industrial insulation, and other scenarios. Vacuum sealing of the container prevents water loss during crosslinking in the solution or colloid and avoids the inhibitory effect of oxygen in the air on the crosslinking reaction.
[0032] After the components are mixed, the first crosslinking component and the second crosslinking component crosslink through covalent bonds, ionic bonds or hydrogen bonds to form a continuous solid network. The phase change material is then encapsulated in the solid network, causing the phase change energy storage material in this application to lose its fluidity and achieve gelation.
[0033] In one embodiment, the process of gelling the material includes: keeping the container in an environment with a temperature range of 30-90°C and a humidity range of 20-80% for 5-24 hours until the material gels.
[0034] The preparation method described in this application is applicable to the formation of a continuous solid network by chemical crosslinking of the first and second crosslinking components in the formulation. For example, when the first crosslinking component is acrylamide and the second crosslinking component is N,N'-methylenebisacrylamide, the acrylamide and N,N'-methylenebisacrylamide are chemically crosslinked through covalent bonds, and the preparation method described in this application can be used in this case. Alternatively, a combination of N-isopropylacrylamide as the first crosslinking component and N,N'-methylenebisacrylamide or ethylene glycol dimethacrylate as the second crosslinking component can be used; or a combination of acrylic acid or sodium acrylate as the first crosslinking component and N,N'-methylenebisacrylamide or a multi-component crosslinking agent as the second crosslinking component; or a combination of styrene as the first crosslinking component and divinylbenzene as the second crosslinking component. This application does not limit the scope of these methods.
[0035] Under the insulated and humidified environment of a high and low temperature humidity test chamber, the first cross-linking component containing active double bonds in the solution or colloid forms a long-chain polymer through a free radical-initiated polymerization reaction, which gradually grows into small particle clusters. Two small particle clusters form a cluster spanning the entire structure, forming a continuous solid network, thus completing gelation. Because the phase change material in the liquid phase is encapsulated in the solid-phase network structure, the entire system loses its fluidity, achieving a solid-solid phase change effect. For the specific forming mechanism, please refer to [reference needed]. Figure 1 and Figure 2 .
[0036] In this embodiment of the invention, the phase change material is encapsulated within a solid network structure formed by covalent bonds between the first and second crosslinking components, reducing the probability of leakage during the phase change process. Simultaneously, the porous framework material provides high mechanical strength and stability, effectively addressing the problems of phase separation and severe lifespan degradation in phase change materials.
[0037] In one embodiment, stirring until dissolved into a solution or colloid includes: stirring the solution or colloid at a speed of 200 rpm to 500 rpm for a stirring time of 30 min to 120 min.
[0038] By controlling the speed and mixing time of the mixer, the components can be mixed well, ultimately presenting a solution or colloid.
[0039] In one embodiment, the gelation of the material includes: S330: Repeated freezing and thawing of the container to gel the material.
[0040] The preparation method described in this application is applicable to the formation of a continuous solid network by the first crosslinking component in the formulation through physical crosslinking. When the first crosslinking component in the material formulation forms a continuous solid network through physical crosslinking, the vacuum-sealed material can be transferred to a mold. Since the molecular chains in the solution or colloid have difficulty moving in the ice phase during the freezing process, the parts where the molecular chains contact each other are tightly bound by van der Waals forces and hydrogen bonds, which can become entanglement points. Therefore, through repeated freeze-thaw cycles, the molecular chains can be interconnected to form a solid network spanning the entire structure, thereby causing the solution or colloid to lose its fluidity and achieving gelation. The number of repeated freeze-thaw cycles is usually more than four to ensure sufficient entanglement points are generated between the molecular chains to form a solid network and reduce the probability of leakage of the phase change material.
[0041] For example, when using polyvinyl alcohol (PVA) for crosslinking, the material can be gelled through repeated freeze-thaw cycles due to the large number of hydroxyl groups on the PVA molecular chains. During freezing, water forms ice crystals, and PVA molecules are displaced and aggregate in the amorphous regions, forming ordered PVA chains. During thawing, the ordered PVA chains are entangled together by hydrogen bonds, forming a physical crosslinked network. After multiple freeze-thaw cycles, a stable three-dimensional network can be accumulated and gelled.
[0042] In one embodiment, the gelation of the material includes: S340: Let the container stand for 30-120 minutes; S350: The container is kept warm and moist at 30℃~60℃, causing the material to gel.
[0043] The preparation method described in this application is applicable to the formulation in which the first crosslinking component and the second crosslinking component simultaneously form a continuous solid network through physical crosslinking and chemical crosslinking. For example, when the first crosslinking component is sodium alginate and the second crosslinking component is calcium ions, the preparation method described in this application can be used.
[0044] Specifically, taking calcium ions and sodium alginate as an example, during the standing process, calcium ions and the carboxyl groups in sodium alginate undergo cross-linking through ionic bonds to form a complex, which is a preliminary physical cross-linking network. Then, the container is placed in a high and low temperature humidity test chamber for heat and moisture preservation. Acrylamide molecules undergo free radical polymerization to form a covalent cross-linking network, allowing the entire system to complete the gelation process through both physical and chemical cross-linking. Understandably, chemical cross-linking can also be initiated using a photoinitiator, which can be one or more of α-hydroxy ketones, acylphosphine oxides, benzoin ethers, diphenyliodonium salts, triarylsulfonium salts, aryl diazonium salts, and arylsulfonium salts. This application does not limit this.
[0045] Alternatively, a combination of polyvinyl alcohol as the first crosslinking component and glutaraldehyde as the second crosslinking component can be used. In this case, step 330 can be combined to form a chemical crosslink between polyvinyl alcohol and glutaraldehyde, followed by repeated freeze-thaw cycles to further complete the physical crosslinking and gel the material. Another option is a combination of acrylamide as the first crosslinking component and N,N'-methylenebisacrylamide or ethylene glycol dimethacrylate as the second crosslinking component. In this case, the acrylamide first crosslinking component and N,N'-methylenebisacrylamide or ethylene glycol dimethacrylate undergo chemical crosslinking, while the gelatin molecules form a physical crosslinking network through hydrogen bonds, hydrophobic interactions, and ionic interactions, thus gelling the material.
[0046] In one embodiment, the gelation of the material includes: S360: Let the container stand for 30-120 minutes; S370: Add a photoinitiator to gel the material.
[0047] The following will explain the solution of this application with reference to embodiments. Those skilled in the art will understand that the following embodiments are for illustrative purposes only and should not be considered as limiting the scope of this application. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in the art or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.
[0048] Comparative Example 1 A traditional solid-liquid phase change energy storage material prepared from an inorganic salt aqueous solution includes the following steps: (1) Add 99 parts of 4.11 mol / L ammonium chloride aqueous solution and 1 part of disodium hydrogen phosphate to the reaction vessel in sequence, and stir thoroughly for 50 min at a speed of 300 rpm and a temperature of 20℃ to obtain a solution or colloid; (2) The above solution or colloid is bottled into a sealed bag, and 1 part of polyurethane foam board is soaked in it and vacuum sealed using a vacuum sealing machine.
[0049] The relevant parameters of the phase change energy storage material prepared in this comparative example are shown in Table 1. The DSC test results are referenced. Figure 5 After repeated melting and solidification tests, phase change energy storage material and polyurethane foam board prepared in this comparative example showed phase separation, which was particularly noticeable when placed vertically. The compressive strength of this phase change energy storage material was 0.2 MPa.
[0050] Comparative Example 2 (1) 93 parts of 4.11 mol / L ammonium chloride aqueous solution, 6 parts of acrylamide, 0.08 parts of N,N'-methylenebisacrylamide, 0.03 parts of potassium persulfate and 1 part of disodium hydrogen phosphate were added to the reaction vessel in sequence and stirred thoroughly for 50 min at a speed of 300 rpm and a temperature of 20°C to obtain a solution or colloid. (2) The above solution or colloid is packaged into a sealed bag and vacuum sealed using a vacuum sealing machine.
[0051] (3) Transfer the above-mentioned sealed bag to the mold and place it in a high and low temperature humidity test chamber for heat preservation and humidification. The temperature is 65℃, the humidity is 40%, and the heat preservation and humidification time is 18h to complete the gelation of the material.
[0052] The relevant parameters of the phase change energy storage material prepared in this embodiment are shown in Table 1. The DSC test results are referenced. Figure 13 .
[0053] Compared to Comparative Example 1, Comparative Example 2 additionally added 6 parts acrylamide, 0.08 parts N,N'-methylenebisacrylamide, and 0.03 parts potassium persulfate to form a stable solid network, resulting in a phase change energy storage material with superior performance. Specifically, after repeated melting and solidification tests, the phase change energy storage material prepared in this comparative example did not exhibit phase separation and maintained a solid state throughout the entire phase change process. The possible reason is that the liquid phase change energy storage material is encapsulated within a solid network framework, causing the entire system to lose its fluidity and achieving a solid-solid phase change effect. The molding mechanism is as follows: Figure 1 As shown.
[0054] Compared to Comparative Example 1, Comparative Example 2 reduced the amount of polyurethane foam board by one part, resulting in a lower compressive strength of the prepared phase change energy storage material, which was 0.02 MPa. This may be due to the lack of the skeletal support provided by the polyurethane foam board.
[0055] Compared with Comparative Example 1, Comparative Example 2 added crosslinking components, which caused the prepared phase change energy storage material to gel, and its thermal conductivity was lower than that of the liquid phase change energy storage material, only 0.502 W / (m·K).
[0056] Example 1 A method for preparing a phase change energy storage material includes: (1) 93 parts of 4.11 mol / L ammonium chloride aqueous solution, 6 parts of acrylamide, 0.08 parts of N,N'-methylenebisacrylamide, 0.03 parts of potassium persulfate and 1 part of disodium hydrogen phosphate were added to the reaction vessel in sequence and stirred thoroughly for 50 min at a speed of 300 rpm and a temperature of 20°C to obtain a solution or colloid. (2) The above solution or colloid is bottled into a sealed bag, and 1 part of polyurethane foam board is soaked in it and vacuum sealed using a vacuum sealing machine.
[0057] (3) Transfer the above-mentioned sealed bag to the mold and place it in a high and low temperature humidity test chamber for heat preservation and humidification. The temperature is 65℃, the humidity is 40%, and the heat preservation and humidification time is 18h to complete the gelation of the material.
[0058] The relevant parameters of the phase change energy storage material prepared in this embodiment are shown in Table 1. The DSC test results are referenced. Figure 6 The DSC test results after 200 cycles are referenced. Figure 7 The DSC test results after 500 cycles are referenced. Figure 8 .
[0059] Compared to Comparative Example 1, Example 1 additionally added 6 parts acrylamide, 0.08 parts N,N'-methylenebisacrylamide, and 0.03 parts potassium persulfate to form a stable solid network, resulting in superior performance of the prepared phase change energy storage material. Specifically, after repeated melting and solidification tests, the phase change energy storage material of this example did not exhibit phase separation and maintained a solid state throughout the entire phase change process. The possible reason is that the liquid phase change material is encapsulated within the solid network framework, causing the entire system to lose its fluidity and achieving a solid-solid phase change effect.
[0060] Compared to Comparative Example 2, the addition of one part of polyurethane foam board in Example 1 resulted in a phase change energy storage material with superior performance, specifically manifested in the compressive strength of 0.30 MPa. This is likely because the polyurethane foam board acts as a skeletal support, allowing the phase change material to cross-link and solidify within the voids of the foam board, completely filling them and resulting in a higher compressive strength than with pure polyurethane foam board. Furthermore, compared to Comparative Example 2, the thermal conductivity of the phase change energy storage material obtained in Example 1 is lower. This is likely because the polyurethane foam board itself has very low thermal conductivity, and the addition of the foam board reduces the overall thermal conductivity. Phase change energy storage materials with low thermal conductivity can be applied to building envelopes, industrial insulation, and other fields, thereby achieving better thermal insulation effects.
[0061] Furthermore, after 200 and 500 melt-solidification cycles, the phase change energy storage material prepared in Example 1 still did not exhibit phase separation, maintaining good energy storage performance and high stability. The specific process of the melt-solidification cycle is as follows: the phase change energy storage material is heated to 25°C and then cooled to -30°C, which constitutes one cycle.
[0062] Example 2 A method for preparing a phase change energy storage material includes: (1) 91 parts of 4.11 mol / L ammonium chloride aqueous solution, 8 parts of polyvinyl alcohol, 0.09 parts of glutaraldehyde, 0.04 parts of ammonium persulfate and 1 part of borax were added to the reaction vessel in sequence and stirred thoroughly for 50 min at a speed of 300 rpm and a temperature of 20℃ to obtain a solution or colloid. (2) The above solution or colloid is bottled into a sealed bag, and 1 part of polyurethane foam board is soaked in it and vacuum sealed using a vacuum sealing machine.
[0063] (3) Place the vacuum-sealed material into a -30°C cold storage and freeze it. After it is completely frozen, melt it at 30°C. Repeat the freezing-melting process 8 times to complete the gelation of the material.
[0064] The relevant parameters of the phase change energy storage material prepared in this embodiment are shown in Table 1. The DSC test results are referenced. Figure 9 .
[0065] Compared to Comparative Example 1 and Example 1, Example 2 uses less ammonium chloride aqueous solution. Other components are replaced with 8 parts polyvinyl alcohol, 0.09 parts glutaraldehyde, 0.04 parts ammonium persulfate, and 1 part borax. This allows polyvinyl alcohol and glutaraldehyde to form a stable solid network through physicochemical crosslinking. The resulting phase change energy storage material exhibits superior performance compared to Comparative Example 1. However, there are differences in some properties compared to Example 1. Specifically, the phase change energy storage material prepared in this example has a compressive strength of 0.4 MPa, higher tensile strength, and better elasticity and flexibility. This may be because Example 2 also involves physicochemical crosslinking, resulting in a more complex "multi-network structure," which enhances the elasticity of the phase change energy storage material.
[0066] Example 3 A method for preparing a phase change energy storage material includes: (1) 93 parts of 4.11 mol / L ammonium chloride aqueous solution, 6 parts of N-isopropylacrylamide, 0.08 parts of dimethylacrylamide, 0.03 parts of azobisisobutyronitrile and 1 part of borax were added to the reaction vessel in sequence and stirred thoroughly for 50 min at a speed of 300 rpm and a temperature of 20℃ to obtain a solution or colloid. (2) The above solution or colloid is bottled into a sealed bag, and 1 part of polyurethane foam board is soaked in it and vacuum sealed using a vacuum sealing machine.
[0067] (3) Transfer the above-mentioned sealed bag to the mold and place it in a high and low temperature humidity test chamber for heat preservation and humidification. The temperature is 65℃, the humidity is 40%, and the heat preservation and humidification time is 18h to complete the gelation of the material.
[0068] The relevant parameters of the phase change energy storage material prepared in this embodiment are shown in Table 1. The DSC test results are referenced. Figure 10 .
[0069] Compared to Example 1, Example 3, which incorporates 6 parts N-isopropylacrylamide, 0.08 parts dimethylacrylamide, 0.03 parts azobisisobutyronitrile, and 1 part borax, produces a phase change energy storage material with superior performance compared to Comparative Example 1. However, it differs from Example 1 in some properties, specifically in its lower latent heat value, lower phase change initiation temperature, and lower tensile strength. The compressive strength of the phase change energy storage material prepared in this example is 0.25 MPa, possibly because it contains hydrophobic isopropyl groups, making it more sensitive to temperature. Compared to Example 1, the network stability formed by crosslinking in Example 3 is poor.
[0070] Example 4 A method for preparing a phase change energy storage material includes: (1) 93 parts of 4.11 mol / L ammonium chloride aqueous solution, 6 parts of polyethylene glycol diacrylate, 0.08 parts of dimethicone, 0.03 parts of ammonium persulfate, 1 part of disodium hydrogen phosphate, and 1 part of 2-hydroxy-2-methyl-1-[4-(2-hydroxyethoxy)phenyl]-1-propanone were added to the reaction vessel in sequence and stirred thoroughly for 50 min at a speed of 300 rpm and a temperature of 20°C to obtain a solution or colloid; (2) The above solution or colloid is bottled into a sealed bag, and 1 part of polyurethane foam board is soaked in it and vacuum sealed using a vacuum sealing machine.
[0071] (3) Transfer the sealed bag to the mold, place it in the light curing test chamber, and irradiate it with a UV lamp to complete the gelation of the material.
[0072] The relevant parameters of the phase change energy storage material prepared in this embodiment are shown in Table 1. The DSC test results are referenced. Figure 11 .
[0073] Compared with Comparative Example 1 and Example 1, Example 4, which added 6 parts of polyethylene glycol diacrylate, 0.08 parts of dimethicone, 0.03 parts of ammonium persulfate and 1 part of disodium hydrogen phosphate, produced a phase change energy storage material with superior performance compared to Comparative Example 1. However, it differed from Example 1 in some properties. Specifically, the compressive strength of the phase change energy storage material prepared in this example was 0.40 MPa, but its tensile strength and flexibility were lower. This may be because the phase change energy storage material prepared in this example had a high crosslinking density and a tight network structure, resulting in higher compressive strength but weaker hydrophilicity, leading to weaker elasticity and toughness.
[0074] Example 5 A method for preparing a phase change energy storage material includes: (1) 93 parts of 4.11 mol / L ammonium chloride aqueous solution, 4 parts of acrylamide, 2 parts of sodium alginate, 0.08 parts of N,N'-methylenebisacrylamide, 0.04 parts of calcium chloride, 0.03 parts of ammonium persulfate and 1 part of borax were added to the reaction vessel in sequence and stirred thoroughly for 50 min at a speed of 300 rpm and a temperature of 20°C to obtain a solution or colloid; (2) The above solution or colloid is bottled into a sealed bag, and 1 part of polyurethane foam board is soaked in it and vacuum sealed using a vacuum sealing machine.
[0075] (3) Transfer the sealed bag to the mold and place it in a high and low temperature humidity test chamber for heat preservation and humidification. The temperature is 70℃, the humidity is 40%, and the heat preservation and humidification time is 18h to complete the gelation of the material.
[0076] The relevant parameters of the phase change energy storage material prepared in this embodiment are shown in Table 1. The DSC test results are referenced. Figure 12 .
[0077] Compared to Comparative Example 1 and Example 1, Example 5, which incorporates 4 parts acrylamide, 2 parts sodium alginate, 0.08 parts N,N'-methylenebisacrylamide, 0.04 parts calcium chloride, 0.03 parts ammonium persulfate, and 1 part borax, produces a phase change energy storage material with superior performance compared to Comparative Example 1. However, it differs from Example 1 in some properties. Specifically, the overall compressive and tensile strengths of the phase change energy storage material prepared in this example are relatively poor, with a compressive strength of 0.2 MPa. This may be because the two composite crosslinking methods in this example influence each other, leading to a decrease in crosslinking density. Furthermore, due to the different crosslinking components, the phase change energy storage materials obtained in Examples 2-5 have lower thermal conductivity. The appropriate method can be selected based on specific application requirements.
[0078] Table 1 Parameter Table for Embodiments
[0079] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.
[0080] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.
[0081] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.
[0082] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.
Claims
1. A phase change energy storage material, characterized in that, By weight, the phase change energy storage material comprises 70-90 parts of phase change material, 2-20 parts of the first crosslinking component, 0-2 parts of the second crosslinking component, 0.01-0.08 parts of initiator, 0.01-1 parts of nucleating agent, 0.01-6 parts of surfactant and 0.01-10 parts of porous framework material; Wherein, the first crosslinking component and the second crosslinking component are used to crosslink and form a continuous solid network; or, the first crosslinking component crosslinks to form a continuous solid network.
2. The phase change energy storage material according to claim 1, characterized in that, The porous skeleton material includes one or more of polyurethane foam board, rock wool board, hollow plastic board, nano-aerogel felt and nano-aerogel board.
3. The phase change energy storage material according to claim 1, characterized in that, The first crosslinking component comprises monomers and / or polymers, and the second crosslinking component comprises a crosslinking agent; wherein, The monomers include one or more of acrylamide, N-isopropylacrylamide, divinylbenzene, acrylic acid, N-hydroxyacrylamide, epoxy acrylic acid, hydroxyethyl acrylate, acrylate amine, cycloolefin monomers, and vinylpyrrolidone; and / or, The polymer includes one or more of polyvinyl alcohol, vinyl polyvinyl alcohol, gelatin, sodium alginate, and chitosan; and / or, The crosslinking agent includes one or more of N,N'-methylenebisacrylamide, dicyandiamide, tetrafluoroethylene, glutaraldehyde, trifluorochlorocyanuric acid, dimethyl glutarate, isocyanate, dimethylnitrosamine, iron ions, calcium ions, and trivalent aluminum ions.
4. The phase change energy storage material according to claim 1, characterized in that, The phase change material includes one or more of hydrated salts, inorganic salts, and organic solutions; and / or, The initiator includes one or more of persulfate, hydrogen peroxide, sodium perchlorate, sulfite, dichloroperoxide, tetramethylethylenediamine, benzophenone, benzophenone, azo compounds, and benzoyl peroxide; and / or, Nucleating agents include one or more of polyethylene, talc, mica, borax, and phosphates; and / or, The surfactant includes one or more of sodium dodecyl sulfate, ammonium dodecyl sulfate, sodium alkylbenzene sulfonate, fatty acid salts, hexadecyltrimethylammonium chloride, benzalkonium chloride, polyethylene ether, fatty alcohol ether, polyoxyethylene allyl ether, lauroylamine, and betaine.
5. A method for preparing a phase change energy storage material according to any one of claims 1 to 4, characterized in that, include: The phase change material, the first crosslinking component, the second crosslinking component, the initiator, the nucleating agent, and the surfactant are added to the reaction vessel and stirred until dissolved into a solution or colloid. The solution or colloid is placed in a container, the porous framework material is placed into the solution or colloid, and then vacuum sealed. This allows the material to complete gelation.
6. The preparation method according to claim 5, characterized in that, The process of gelling the material includes: The container is kept warm and moist for 5 to 24 hours in an environment with a temperature range of 30 to 90°C and a humidity range of 20 to 80% until the material gels.
7. The preparation method according to claim 6, characterized in that, The stirring until dissolved into a solution or colloid includes: The solution or colloid was stirred at a speed of 200 rpm to 500 rpm for 30 min to 120 min.
8. The preparation method according to claim 5, characterized in that, The process of gelling the material includes: Repeated freezing and thawing of the container causes the material to gel.
9. The preparation method according to claim 5, characterized in that, The process of gelling the material includes: Let the container stand for 30 to 120 minutes; The container is kept warm and moist in an environment with a temperature range of 30℃ to 60℃ and a humidity range of 20% to 80%, which causes the material to gel.
10. The preparation method according to claim 9, characterized in that, The initiator includes a photoinitiator, and the process of gelling the material includes: Let the container stand for 30 to 120 minutes; The material is gelled by irradiation with a light source.