An active thermal management flexible thermal storage composite phase change material, its preparation method and application

Abstract

This invention relates to an active thermal management flexible thermal storage composite phase change material, its preparation method, and its applications, belonging to the field of composite materials. The composite phase change material has a two-layer structure: an upper electrothermal conversion functional layer and a lower flexible phase change thermal storage layer. The flexible phase change thermal storage layer is composed of a flexible polyether polymer network and an organic solid-liquid phase change material in situ supported therein. The electrothermal conversion functional layer is uniformly coated onto the flexible phase change thermal storage layer using methods such as spin coating, blade coating, and screen printing to obtain the active thermal management flexible thermal storage composite phase change material. This composite material, possessing good room-temperature flexibility, integrates electrothermal conversion and thermal energy management characteristics, showing broad application prospects in electronic device thermal management, building temperature control, and wearable health devices.

Description

Technical Field

[0001] This invention relates to an active thermal management flexible thermal storage composite phase change material, its preparation method, and its application, belonging to the field of composite materials. Background Technology

[0002] Thermal energy management technology can effectively solve the problem of imbalance between thermal energy supply and demand in time and space, thereby improving energy efficiency. Among these technologies, phase change materials (PCMs) can store and release latent heat of phase change through reversible phase changes (from liquid to solid and solid to liquid), showing great application potential in temperature control and heat dissipation of electronic devices and heating and insulation in the building industry. (W. Aftab, X. Huang, W. Wu, Z. Liang, A. Mahmood, R. Zou, Energy Environ. Sci. 2018, 11, 1392-1424.)

[0003] Traditional passive phase change thermal management (PCM) technology relies solely on temperature differences to drive the storage and release of thermal energy, which is often limited by factors such as season and environment. Active PCM technology, on the other hand, achieves thermal energy conversion through energy conversion processes, thereby driving the phase change thermal storage process. Simultaneously, the phase change thermal storage layer can effectively regulate the ambient temperature of the target object, maintaining it within a suitable operating temperature range. Nevertheless, the internally coupled thermal energy conversion and phase change thermal storage elements generally exhibit significant room-temperature rigidity, resulting in poor mechanical properties and flexibility of active PCM materials, making it difficult to meet practical application requirements. To date, there are few reports on active thermal management flexible thermal storage composite PCM materials. Therefore, the development and fabrication of active thermal management flexible thermal storage composite PCM materials has significant application value in the fields of electronic device thermal management and wearable devices for human health. Summary of the Invention

[0004] This invention aims to combine electrothermal conversion with flexible thermal storage technology to construct an active flexible phase change thermal management material with a dual-functional layer structure. The upper electrothermal conversion functional layer achieves electrothermal conversion through the Joule heating effect; the lower flexible phase change thermal storage layer regulates the ambient temperature of the target object through the storage and release of thermal energy. The flexible phase change thermal storage layer is prepared by molecular structure design to obtain a polyetheramine polymer network with good flexibility and compatibility with phase change components, and further encapsulates the phase change components. Conductive paste is uniformly coated onto the surface of the flexible phase change thermal storage layer using methods such as blade coating and spin coating to construct the electrothermal conversion functional layer, thereby achieving functional coupling of electrothermal conversion and flexible thermal storage. This solves the problem of high room temperature rigidity of the material while endowing it with electrothermal conversion efficiency.

[0005] The purpose of this invention is to provide an active thermal management flexible thermal storage composite phase change material. This phase change material, while possessing good room-temperature flexibility, integrates electrothermal conversion and thermal energy management characteristics, has a simple preparation process, and has broad application prospects.

[0006] An active thermal management flexible thermal storage composite phase change material is disclosed. The composite phase change material has a two-layer structure: an upper electrothermal conversion functional layer and a lower flexible phase change thermal storage layer. The flexible phase change thermal storage layer is composed of a flexible polyether polymer network and an organic solid-liquid phase change material in situ supported therein. The electrothermal conversion functional layer is uniformly coated onto the flexible phase change thermal storage layer using methods such as spin coating, blade coating, and screen printing to obtain the active thermal management flexible thermal storage composite phase change material.

[0007] Furthermore, the flexible polyetheramine polymer network is a polymer having the following general structural formula, where n is an integer from 10 to 10000.

[0008]

[0009] The flexible polyetheramine polymer network of the present invention is formed by ring-opening polymerization of polyetheramine molecules and ethylene glycol diglycidyl ether molecules, with the mass ratio of polyetheramine to solvent being 1:(5-10).

[0010] Preferably, the solvent is at least one selected from tetrahydrofuran, dioxane, petroleum ether, acetone, chloroform, carbon disulfide, benzene, toluene, nitrobenzene, chlorobenzene, cyclohexane, and n-hexane.

[0011] Preferably, the organic phase change material is at least one of the following: dodecane, tridecane, tetradecane, pentadecane, hexadecane, heptadecane, octadecane, nonadecane, eicosane, n-dodecyl alcohol, n-tetradecyl alcohol, n-hexadecyl alcohol, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, octadecanoic acid, butyl stearate, methyl palmitate, methyl stearate, octadecyl mercaptoacetate, acetamide, phorone, polyethylene glycol, and polyvinyl alcohol.

[0012] Preferably, the electrothermal conversion functional layer is at least one of conductive pastes such as conductive silver paste, conductive carbon paste, conductive copper paste, and conductive ceramic paste, and the mass ratio of the electrothermal conversion functional layer to the flexible phase change heat storage layer is 1:3 to 1:100.

[0013] Preferably, the conductive paste is applied via at least one of spin coating, blade coating, and screen printing. Another object of the present invention is to provide a method for preparing the above-mentioned active thermal management flexible thermal storage composite phase change material.

[0014] A method for preparing an active thermal management flexible thermal storage composite phase change material includes the following process steps:

[0015] ①Preparation of an organic dispersion system of polyetheramine molecules and ethylene glycol diglycidyl ether molecules;

[0016] ② Add the phase change molecule to the dispersion system obtained in step ①, and load the phase change component in situ through ring-opening polymerization to obtain an organic prepolymer;

[0017] ③The prepolymer obtained in step ② is allowed to stand, the solvent is removed, and it is heated and dried to obtain a flexible phase change thermal storage layer.

[0018] ④The flexible phase change thermal storage layer obtained in step ③ is coated with an electrothermal conversion functional layer and cured to obtain an active thermal management flexible thermal storage composite phase change material with a double-layer structure.

[0019] The active thermal management flexible thermal storage composite phase change material of the invention is prepared by designing a polyetheramine polymer network with good flexibility and compatibility with phase change components through molecular structure design, and further coating the phase change components to obtain a flexible phase change thermal storage layer, and further coupling an electrothermal conversion functional layer to realize the preparation of the active thermal management flexible thermal storage composite phase change material.

[0020] In the above technical solution, step ① involves dispersing polyetheramine molecules and ethylene glycol diglycidyl ether molecules in an organic solvent and mixing them uniformly by magnetic stirring. The mass ratio of the polyetheramine molecules to the ethylene glycol diglycidyl ether molecules is (1-3):1; and the mass ratio of the polyetheramine to the organic solvent is 1:(5-10).

[0021] Furthermore, the magnetic stirring time is 5 to 10 hours, the system temperature is preferably 35°C, and the rotation speed is preferably 700 r / min.

[0022] In the above technical solution, in step ②, the phase change component is added to the mixed system obtained in step ①, and magnetic stirring is used to make it mix evenly; under heating conditions, the polyetheramine molecules and ethylene glycol diglycidyl ether molecules undergo a ring-opening polymerization reaction in the organic dispersion system to generate a polyetheramine polymer network and load the phase change molecules in situ to obtain an organic prepolymer.

[0023] Furthermore, the preferred heating temperature during the reaction process is 45°C; the preferred reaction time is 7–13 h; and the preferred rotation speed is 400 r / min.

[0024] In the above technical solution, in step ③, the obtained prepolymer is allowed to stand at room temperature, the solvent is removed, and it is heated and dried to obtain a flexible phase change thermal storage layer.

[0025] Furthermore, the settling temperature is room temperature, the settling time is preferably 8 to 17 hours, the heating temperature is preferably 120°C, and the drying time is preferably 9 to 15 hours.

[0026] In the above technical solution, step ④ involves coating the flexible phase change thermal storage layer obtained in step ③ with an electrothermal conversion functional layer and then curing it to obtain an active thermal management flexible thermal storage composite phase change material with a double-layer structure.

[0027] Furthermore, the electrothermal functional layer is applied by scraping, and the curing temperature is preferably 80℃; the curing time is preferably 3-8h.

[0028] Another object of the present invention is to provide the application of the above-mentioned active thermal management flexible thermal storage composite phase change material as an intelligent temperature control device.

[0029] Furthermore, active thermal management flexible thermal storage composite phase change materials have important application value in the fields of intelligent temperature control devices, thermal management of electronic devices, and wearable health devices.

[0030] The beneficial effects of this invention are as follows: The active flexible phase change thermal management material constructed by this invention integrates electrothermal conversion and thermal energy management characteristics based on good room temperature flexibility, and its application is not limited by seasonal or environmental factors. This flexible phase change thermal management material has a dual-functional layer structure. The upper electrothermal conversion functional layer can realize the electrothermal conversion process through the Joule heating effect; the lower flexible phase change thermal storage layer can regulate the ambient temperature of the target object through the storage and release of thermal energy. The flexible phase change thermal storage layer is prepared by molecular structure design to obtain a polyetheramine polymer network with good flexibility and compatibility with phase change components, and further encapsulates the phase change components. Conductive paste is uniformly coated onto the surface of the flexible phase change thermal storage layer using methods such as blade coating and spin coating, thereby realizing the functional coupling of electrothermal conversion and flexible thermal storage.

[0031] The active thermal management flexible thermal storage composite phase change material of the present invention can regulate the phase change operating temperature range of the material by directional selection of organic phase change energy storage materials, and has broad application prospects in the fields of electronic device thermal management, building temperature regulation and human health wearables. Attached Figure Description

[0032] Figure 1 This is a room temperature bending photograph of the flexible composite phase change material in Example 1.

[0033] Figure 2 This is a cross-sectional SEM image of the active thermal management flexible composite phase change material in Example 1.

[0034] Figure 3 This is a comparison diagram of the shaping effects of hexadecyl alcohol and flexible composite phase change material described in Example 1.

[0035] Figure 4 The image shows the DSC curve of the active thermal management flexible composite phase change material described in Example 1.

[0036] Figure 5The graph shows the electrothermal conversion curve of the active thermal management flexible composite phase change material described in Example 1. Detailed Implementation

[0037] The following non-limiting embodiments are intended to enable those skilled in the art to more fully understand the invention, but do not limit the invention in any way.

[0038] Unless otherwise specified, the experimental methods described in the following examples are conventional methods; the reagents and materials described are commercially available unless otherwise specified.

[0039] Example 1

[0040] 1. Disperse 1.5g of ethylene glycol diglycidyl ether and 1.5g of polyetheramine in 10.0g of toluene solution. Stir magnetically at 700r / min for 8h to make the system homogeneous and stable.

[0041] 2. Under magnetic stirring at 400 r / min, 3.0 g of cetyl alcohol was added to the system obtained in step (1), and the reaction was carried out at 45 °C for 10 h, so that the ether amine molecules and ethylene glycol diglycidyl ether molecules underwent ring-opening polymerization in the organic dispersion system to generate a polyether amine polymer network and in-situ loaded phase change molecules, thus obtaining an organic prepolymer.

[0042] 3. After the above system is left to stand at room temperature for 8 hours and dried at 120°C for 9 hours, a polyether amine-based flexible shape-stabilized phase change material with a phase change component loading rate of 50% is obtained.

[0043] 4. Apply conductive silver paste evenly to the surface of the flexible shaped phase change heat storage layer by scraping, and cure at 80℃ for 5 hours to obtain the active thermal management flexible composite phase change material.

[0044] Figure 1 The images show room-temperature bending of the flexible composite phase change material, demonstrating its good flexibility. A scanning electron microscope image of its cross-section is also shown. Figure 2 As shown, the results indicate that it has a dual-functional layer structure, with the upper layer being an electrothermal conversion functional layer and the lower layer being a flexible thermal storage layer.

[0045] The shaping effect of the composite phase change material was tested at 80℃. Figure 3 In section I, the obtained flexible composite phase change material has excellent shape stability and will not leak at 80°C; while in section II, the phase change material changes from a solid to a flowable liquid after being heated for a period of time.

[0046] Differential scanning calorimetry (DSC) was used to test the composite phase change material, and the results are as follows: Figure 4The DSC curves I, II, and III show composite phase change materials loaded with dodecanol (obtained by replacing hexadecylol with dodecanol in Example 1), tetradecylol (obtained by replacing hexadecylol with tetradecylol in Example 1), and hexadecylol phase change molecules, respectively. The phase change temperature is adjustable within the temperature range of 20-70℃, and the phase change enthalpy is between 30-150J / g, providing a guarantee for the practical application of phase change energy storage materials.

[0047] The thermal management capability of flexible composite phase change materials was tested through electrothermal conversion performance testing. Figure 5 As shown, when a 3V voltage is applied to the composite material, the composite phase change material exhibits good electrothermal conversion effect, indicating that the composite phase change material has good energy conversion and thermal management performance.

[0048] Example 2-24

[0049] In Example 1, the hexadecane was replaced with dodecane, tridecane, tetradecane, pentadecane, hexadecane, heptadecane, octadecane, nonadecane, eicosane, n-dodecyl alcohol, n-tetradecyl alcohol, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, octadecanoic acid, butyl stearate, methyl palmitate, methyl stearate, octadecyl mercaptoacetate, acetamide, phorone, polyethylene glycol, and polyvinyl alcohol to obtain active thermal management flexible composite phase change materials loaded with different phase change components. Other conditions remained the same as in Example 1. The resulting active thermal management flexible composite phase change materials exhibited good thermal management performance.

[0050] Examples 25-72

[0051] The electrothermal conversion functional layers in Examples 1-24 were replaced with conductive carbon paste and conductive copper paste, respectively, to obtain active thermal management flexible composite phase change materials with different electrothermal conversion capabilities. Other conditions remained the same as in Example 1. The resulting active thermal management flexible composite phase change materials exhibited excellent energy conversion and thermal management performance.

[0052] Example 73

[0053] 1. Disperse 1.5g of ethylene glycol diglycidyl ether and 1.5g of polyetheramine in 10.0g of toluene solution. Stir magnetically at 700r / min for 8h to make the system homogeneous and stable.

[0054] 2. Under magnetic stirring at 400 r / min, 1.5 g cetyl alcohol and 1.5 g tetradecyl alcohol were added to the system obtained in step (1), and the reaction was carried out at 45°C for 10 h. This allowed the ether amine molecules and ethylene glycol diglycidyl ether molecules to undergo ring-opening polymerization in the organic dispersion system to generate a polyether amine polymer network and load phase change molecules in situ, thus obtaining an organic prepolymer.

[0055] 3. After the above system is left to stand at room temperature for 8 hours and dried at 120°C for 9 hours, a polyether amine-based flexible shape-stabilized phase change material with a phase change component loading rate of 50% is obtained.

[0056] 4. Apply conductive silver paste evenly to the surface of the flexible shaped phase change heat storage layer by scraping, and cure at 80℃ for 5 hours to obtain the active thermal management flexible composite phase change material.

[0057] Examples 74-193

[0058] In Example 1, the hexadecane was replaced with a 1:1 mixture of the two different organic solid-liquid phase change materials (dodecane, tridecane, tetradecane, pentadecane, hexadecane, heptadecane, octadecane, nonadecane, eicosane, n-dodecyl alcohol, n-tetradecyl alcohol, n-hexadecyl alcohol, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, and octadecanoic acid) to obtain an active thermal management flexible composite phase change material loaded with different phase change components. Other conditions remained the same as in Example 1. The resulting active thermal management flexible composite phase change material exhibited excellent thermal management performance.

Claims

1. An active thermal management flexible thermal storage composite phase change material, characterized in that: The composite phase change material has a two-layer structure, with the upper layer being an electrothermal conversion functional layer and the lower layer being a flexible phase change heat storage layer. The electrothermal conversion functional layer is at least one of conductive silver paste, conductive carbon paste, conductive copper paste, and conductive ceramic paste. The flexible phase change thermal storage layer is composed of a flexible polyether polymer network and an organic solid-liquid phase change material loaded therein in situ; The flexible polyether polymer network is a polymer having the following general structural formula: ； n is an integer from 10 to 10000.

2. The active thermal management flexible thermal storage composite phase change material according to claim 1, characterized in that: The flexible polyetheramine polymer network is formed by the polymerization reaction of polyetheramine and ethylene glycol diglycidyl ether in a solvent, with the mass ratio of polyetheramine molecules to ethylene glycol diglycidyl ether molecules being (1-3):

1.

3. The active thermal management flexible thermal storage composite phase change material according to claim 2, characterized in that: The mass ratio of the polyetheramine to the solvent is 1:(5-10), and the solvent is at least one selected from tetrahydrofuran, dioxane, petroleum ether, acetone, chloroform, carbon disulfide, benzene, toluene, nitrobenzene, chlorobenzene, cyclohexane, and n-hexane.

4. The active thermal management flexible thermal storage composite phase change material according to claim 1, characterized in that: The organic solid-liquid phase change material is at least one of the following: dodecane, tridecane, tetradecane, pentadecane, hexadecane, heptadecane, octadecane, nonadecane, eicosane, n-dodecyl alcohol, n-tetradecyl alcohol, n-hexadecyl alcohol, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, octadecanoic acid, butyl stearate, methyl palmitate, methyl stearate, octadecyl mercaptoacetate, acetamide, phorone, polyethylene glycol, and polyvinyl alcohol.

5. The active thermal management flexible thermal storage composite phase change material according to claim 1, characterized in that: The mass ratio of the electrothermal conversion functional layer to the flexible phase change thermal storage layer is 1:3 to 1:

100.

6. The active thermal management flexible thermal storage composite phase change material according to claim 1, characterized in that: The material is obtained by uniformly coating the electrothermal conversion functional layer onto the flexible phase change thermal storage layer through spin coating, scraping coating, or screen printing.

7. A method for preparing an active thermal management flexible thermal storage composite phase change material according to any one of claims 1 to 6, characterized in that, The process includes the following steps: ①Preparation of an organic dispersion system of polyetheramine molecules and ethylene glycol diglycidyl ether molecules; ② The organic overnight phase change material is added to the obtained dispersion system, and the phase change component is loaded in situ to obtain an organic prepolymer; ③ The organic prepolymer is allowed to stand, the solvent is removed, and it is heated and dried to obtain a flexible phase change thermal storage layer; ④ An active thermal management flexible thermal storage composite phase change material with a double-layer structure is obtained by scraping, spin coating or screen printing an electrothermal conversion functional layer on the flexible phase change thermal storage layer and curing.

8. The application of an active thermal management flexible thermal storage composite phase change material according to any one of claims 1-6, characterized in that: The composite phase change material is used in intelligent temperature control devices, electronic thermal management devices, building temperature control, or wearable health devices.

Images