Cacl2.6h2o / cof / pae composite phase change material and preparation method thereof

Abstract

The application relates to a CaCl2.6H2O / COF / PAE composite phase change material and a preparation method thereof. The CaCl2.6H2O / COF / PAE composite phase change material is composed of calcium chloride hexahydrate, an organic framework COF material and a polyacrylate porous material PAE. The polyacrylate porous material PAE is a spherical particle, has rich porous structures inside, and the organic framework COF material is distributed in the pores of the polyacrylate porous material PAE to form a COF / PAE composite material. The COF / PAE composite material serves as a carrier, the calcium chloride hexahydrate phase change material is filled in the pores of the carrier, and the CaCl2.6H2O / COF / PAE composite phase change material is formed. The application utilizes the limited space of the COF / PAE composite carrier with different pore diameters to constrain the heterogeneous nucleation process of the liquid phase, solves the problem that the current CaCl2.6H2O as an inorganic phase change material has a serious supercooling phenomenon, and solves the problem that the phase change space is insufficient or the capillary force is weak after the organic phase change material is encapsulated, so that the energy storage capacity of the phase change material is small and the phase change material is prone to leakage.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of phase change materials, and particularly relates to a CaCl2.6H2O / COF / PAE composite phase change material and a preparation method thereof. BACKGROUND

[0002] Inorganic phase change materials have been widely used in energy storage due to their high latent heat of phase change, excellent thermal conductivity and chemical stability. Especially, hydrated inorganic salts such as calcium chloride hexahydrate (CaCl2.6H2O) have a good application prospect in building energy saving, solar heat storage and cold storage and insulation due to their moderate phase change temperature (about 29 DEG C) and high latent heat value. However, the hydrated inorganic salt will change from solid to liquid during the phase change, resulting in the problem of liquid leakage of the phase change material. The liquid leakage not only affects the heat storage efficiency, but also causes damage to the use environment.

[0003] In order to solve the problem of liquid leakage, researchers usually use porous matrix materials to encapsulate inorganic phase change materials. Common porous materials such as expanded perlite, diatomite and mesoporous silica can effectively adsorb inorganic phase change materials by providing capillary force through pore structure, and can reduce the leakage of liquid during phase change. In addition, the use of porous matrix materials can also effectively improve the thermal cycle stability of inorganic phase change materials. However, although the micropores of the porous material have strong capillary action and can effectively prevent the leakage of the phase change material, the small pore size of the micropores often limits the phase change behavior of the inorganic phase change material, resulting in a decrease in the latent heat value. On the other hand, although the mesoporous material provides sufficient phase change space, its specific surface area is relatively small, and the capillary force is insufficient. In long-term cyclic use, the problem of liquid leakage still exists.

[0004] Therefore, it is of great significance to develop a porous matrix material which can provide sufficient phase change space and appropriate capillary force for the energy storage application of inorganic phase change materials. SUMMARY

[0005] The application aims to provide a CaCl2.6H2O / COF / PAE composite phase change material and a preparation method thereof, which uses the limited space of different pore sizes of the material to constrain the heterogeneous nucleation process of the liquid phase, so as to solve the problems of serious supercooling of the hydrated inorganic salt as the inorganic phase change material and small energy storage capacity and easy leakage of the phase change material due to insufficient phase change space or weak capillary force of the organic material after encapsulation.

[0006] The application is specifically implemented by the following technical scheme, a CaCl2·6H2O / COF / PAE composite phase change material is provided in the application, which is composed of calcium chloride hexahydrate (CaCl2·6H2O), covalent organic framework material (COF) and polyacrylate porous material (PAE), the polyacrylate porous material PAE is spherical particles, which has rich porous structure inside, the covalent organic framework material (COF) is distributed in the pores of the polyacrylate porous material (PAE) to form a COF / PAE composite material, the COF / PAE composite material acts as a carrier, and the calcium chloride hexahydrate phase change material is filled in the pores of the carrier to form the CaCl2·6H2O / COF / PAE composite phase change material.

[0007] The application further provides a preparation method of the CaCl2·6H2O / COF / PAE composite phase change material, which comprises the following steps

[0008] (1) preparing the polyacrylate porous material PAE

[0009] Glycidyl methacrylate, trimethylolpropane triacrylate, PEG-PPG-PEG and benzoyl peroxide are dissolved in toluene to form an oil phase by mixing uniformly at room temperature by using an ultrasonic chemical reaction kettle;

[0010] Under stirring conditions, ethylenediamine and ethylene glycol are dissolved in water as an aqueous phase, the obtained oil phase is placed in an ice water bath, then the aqueous phase is added dropwise into the oil phase, stirring is performed for 1 h to form a uniform and stable water-in-oil emulsion; nitrogen is introduced into the water-in-oil emulsion, then N,N-dimethylaniline is added thereto, stirring reaction is performed for 5-10 min, then ammonium persulfate and polyvinyl alcohol are added, stirring reaction is performed for 1 h, then tetramethyl ethylenediamine is added dropwise into the reaction system, and stirring reaction is performed for 20-30 min at 55 °C and 400-500 rpm to ensure that the emulsion in the reaction system is dispersed into uniform droplets, at this time, the monomers in the reaction system start to polymerize to form polyacrylate white solid particles, when the white solid particles are no longer generated, stirring is stopped, and the reaction is kept at 55 °C for 30-60 min, then the reaction mixture is filtered, and the filtrate is dried to obtain the polyacrylate porous material PAE;

[0011] (2) preparing a COF / PAE composite carrier

[0012] p-Toluenesulfonic acid monohydrate, triformylphloroglucin is mixed and stirred in deionized water to obtain an organic ligand dispersion; polyacrylate porous material PAE is added to the organic ligand dispersion and stirred uniformly to obtain a mixed dispersion; diaminoanthraquinone is added to the mixed dispersion, and after mixing, it is fully reacted at 120°C under stirring; after the reaction is completed, centrifugal separation is performed, the product is dried at 65°C, and a COF / PAE composite carrier is obtained;

[0013] (3) Preparation of CaCl2·6H2O / COF / PAE composite phase change material

[0014] A certain mass of CaCl2·6H2O crystal is melted at 50°C to obtain a CaCl2 molten liquid, the CaCl2 molten liquid is slowly added to the COF / PAE composite carrier in a vacuum environment, and stirring is performed in the vacuum environment for 30-40 min, and the obtained composite material is dried in a vacuum drying box to obtain a CaCl2·6H2O / COF / PAE composite phase change material.

[0015] In the preparation method of the aforementioned CaCl2·6H2O / COF / PAE composite phase change material, the volume ratio of the water phase to the oil phase in step (1) is 2:5; the mass ratio of glycidyl methacrylate, trimethylolpropane triacrylate, PEG-PPG-PEG, and benzoyl peroxide is 3:1:1:1; the mass ratio of ethylenediamine to ethylene glycol is 7:9, and the total mass of ethylenediamine and ethylene glycol to the total mass of glycidyl methacrylate, trimethylolpropane triacrylate, PEG-PPG-PEG, and benzoyl peroxide is 2:15; the mass of ammonium persulfate to the total mass of glycidyl methacrylate, trimethylolpropane triacrylate, PEG-PPG-PEG, and benzoyl peroxide is 1:20, and the mass of polyvinyl alcohol to the total mass of glycidyl methacrylate, trimethylolpropane triacrylate, PEG-PPG-PEG, and benzoyl peroxide is 1:5.

[0016] In the preparation method of the aforementioned CaCl2·6H2O / COF / PAE composite phase change material, the mass ratio of p-toluenesulfonic acid monohydrate to triformylphloroglucin in step (2) is 23:6; the mass fraction of polyacrylate porous material PAE in the mixed dispersion is 25-35%; and the mass ratio of diaminoanthraquinone to triformylphloroglucin is 1:2.

[0017] In the preparation method of the aforementioned CaCl2·6H2O / COF / PAE composite phase change material, step (3) can be used to prepare CaCl2·6H2O / COF / PAE composite phase change materials containing different mass fractions of CaCl2·6H2O according to different masses of CaCl2·6H2O crystals.

[0018] The present application has obvious advantages and beneficial effects compared with the prior art. By the above technical scheme, the present application can achieve considerable technical progress and practicability, and has wide utilization value, and at least has the following advantages:

[0019] (1) The present application utilizes emulsion polymerization to prepare polyacrylate porous material PAE as the matrix of the composite phase change material. The polyacrylate porous material PAE is spherical particles with rich porous structure inside. The organic framework COF material is in-situ grown in the pores of the polyacrylate porous material PAE to form a COF / PAE composite material. The COF / PAE composite material is used as a composite carrier, and the inorganic phase change material calcium chloride hexahydrate (CaCl2·6H2O) is adsorbed in the pores of the COF / PAE composite carrier by vacuum impregnation. The three-level porous structure of the polyacrylate porous material PAE provides a good place and support for the growth of the organic framework COF material, avoiding the rapid decrease of the specific surface area caused by the accumulation of the organic framework COF material powder. Moreover, the high specific surface area and capillary force of the organic framework COF material can realize high loading and low leakage of calcium chloride hexahydrate.

[0020] (2) In the preparation process of the polyacrylate porous material PAE, the emulsion precipitation polymerization method is used to optimize the oil phase components, the water / oil phase ratio and the selection of emulsifiers to regulate the composition and interfacial tension of the emulsion. Combined with precise control of the reaction temperature and reaction time, the pore structure of the polyacrylate porous material PAE is adjusted. The polyacrylate porous material PAE prepared by the above method has a specific network structure and exhibits excellent hydrophilic adsorption properties, which can be combined with the organic framework COF material to form a composite carrier with multi-level pore structure. By in-situ loading method, the organic framework COF material is directly grown in the pores of the polyacrylate porous material PAE, forming a dense layer of COF grains on the surface of the macropores, realizing the close combination of the polyacrylate porous material PAE and the organic framework COF material, and avoiding the significant reduction of the specific surface area caused by the accumulation of the COF material. When loading CaCl2·6H2O, this composite carrier with multi-level pore structure exhibits the synergistic effect of the polyacrylate mesoporous and COF material microporous: on the one hand, the pore size limitation of the micro-mesoporous composite material can effectively slow down the supercooling phenomenon of CaCl2·6H2O; on the other hand, the microporous structure of the COF material provides a large specific surface area, which produces a strong capillary effect during the phase change process, effectively preventing the leakage of CaCl2·6H2O. In addition, the mesoporous structure of the polyacrylate provides sufficient space for the phase change process of CaCl2·6H2O, ensuring the smooth progress of the phase change behavior, effectively improving the phase change enthalpy value of CaCl2·6H2O and enhancing the energy storage capacity.

[0021] (3) The phase change material structure of the application can improve the specific heat capacity and thermal conductivity of the material, so that it can quickly absorb and release heat, greatly improving the heat storage capacity of the material. By using an improved formula, the aging and performance degradation of the material during the phase change process are delayed, ensuring that the material can still maintain excellent heat storage effect in multiple phase change cycles and prolong the service life of the material. The composite phase change material prepared by the application can quickly respond to temperature changes and quickly complete the phase change during heating or cooling, thereby improving the utilization efficiency of thermal energy and the dynamic response speed.

[0022] (4) The application selects environmentally friendly and non-toxic raw materials, so that the phase change heat storage material will not pollute the environment during production, use and disposal, meeting the requirements of green and sustainable development. By improving the production process, the production process is simplified, the production cost of the material is reduced, and at the same time, in actual application, the economic benefit can be improved through heat recovery and reuse, and energy waste is reduced.

[0023] (5) The application uses COF / PAE composite material as a carrier to adsorb CaCl2·6H2O with a multi-level pore structure, which not only provides sufficient phase change space for the phase change material, significantly increases the energy storage capacity of CaCl2·6H2O, and reduces the leakage phenomenon; at the same time, due to the pore size restriction effect of the micro-mesoporous composite material, the supercooling phenomenon of CaCl2·6H2O is effectively reduced, so that it can be applied to low-temperature phase change energy storage, and it can maintain stable phase change behavior in a variety of environments and temperature ranges, suitable for a wide range of heat storage scenarios, including building heating, industrial waste heat recovery, renewable energy storage, etc., meeting the needs of different fields. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a mechanism diagram of the preparation of CaCl2·6H2O / COF / PAE composite phase change material;

[0025] Figure 2 is a SEM diagram of the COF / PAE composite carrier prepared in Example 1;

[0026] Figure 3 is a SEM diagram of the CaCl2·6H2O / COF / PAE composite phase change material prepared in Example 1;

[0027] Figure 4 is a DSC diagram of CaCl2·6H2O phase change material and CaCl2·6H2O / COF / PAE composite phase change material prepared in Example 1;

[0028] Figure 5 is a DSC diagram of CaCl2·6H2O / COF / PAE composite phase change material prepared in Example 1 after 100 cycles;

[0029] Figure 6 is a CaCl2·6H2O phase change material and a comparison chart of leakage after heating of the CaCl2·6H2O / COF / PAE composite phase change material prepared in Example 1. DETAILED DESCRIPTION

[0030] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the present application will be described clearly and completely below in connection with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without any creative work under the premise that the present application falls within the scope of protection of the present application.

[0031] The present application will be described in detail below with specific embodiments. In the following embodiments, the specific conditions not mentioned are all carried out according to the conventional conditions or the conditions recommended by the manufacturers. The raw materials and reagents used are all conventional products that can be purchased on the market, and the manufacturers are not mentioned.

[0032] Example 1:

[0033] Step (1): Preparation of polyacrylate porous material (PAE)

[0034] Step (1.1): 3 g of glycidyl methacrylate, 1 g of trimethylolpropane triacrylate, 1 g of PEG-PPG-PEG, and 1 g of benzoyl peroxide were dissolved in 10 mL of toluene to form an oil phase, which was mixed uniformly at room temperature by using an ultrasonic chemical reactor;

[0035] Step (1.2): Under stirring conditions, 0.35 g of ethylenediamine and 0.45 g of ethylene glycol were dissolved in 4 mL of water as an aqueous phase, and the oil phase of step (1.1) was placed in an ice water bath (about 5℃), then the aqueous phase was added dropwise into the oil phase, and stirred for 1 h to form a uniform and stable water-in-oil emulsion;

[0036] Step (1.3): Nitrogen was bubbled into the water-in-oil emulsion prepared in step (1.2) to prevent the influence of oxygen in the air on the polymerization reaction in the emulsion, and then 4 drops (about 0.2 mL) of reducing agent N,N-dimethylaniline were added thereto, and stirred for 5-10 min to facilitate the subsequent polymerization reaction; then 0.3 g of oxidant ammonium persulfate and 1.2 g of dispersant polyvinyl alcohol were added to stabilize the emulsion structure, and after stirring for 1 h, 6-8 drops of reducing agent tetramethylethylenediamine were added dropwise to the reaction system, and stirred at 55 °C and 400-500 rpm for 20-30 min to ensure that the emulsion in the reaction system was dispersed into uniform droplets. At this time, the monomers in the reaction system began to polymerize to form white solid particles of polyacrylate. When the white solid particles no longer formed, the stirring was stopped, and the mixture was incubated at 55 °C for 30 min to complete the polymerization reaction of the monomers. Then the reaction mixture was filtered, and the filtrate was dried to obtain a polyacrylate porous material (PAE);

[0037] Step (2): Preparation of COF / PAE composite carrier

[0038] Step (2.1): 230 mg of p-toluenesulfonic acid monohydrate PTSA and 60 mg of trialdehyde-based phloroglucinol Dq were added to 10 mL of deionized water and stirred for 5 min to obtain an organic ligand dispersion;

[0039] Step (2.2): A certain amount of polyacrylate porous material (PAE) prepared in step (1) was added to the organic ligand dispersion prepared in step (2.1) and stirred uniformly to obtain a mixed dispersion, and the mass fraction of the polyacrylate porous material (PAE) in the mixed dispersion was 25%;

[0040] Step (2.3): 30 mg of diaminanthraquinone Tp was added to the mixed dispersion prepared in step (2.2), and after mixing, it was stirred at 120 °C for 18 h to allow it to react fully. After the reaction was completed, it was centrifuged and separated, and the product was dried in an oven at 65 °C for 24 h to obtain a COF / PAE composite carrier.

[0041] Step (3): Preparation of CaCl2·6H2O / COF / PAE composite phase change material

[0042] Melt 0.5 g of CaCl2·6H2O in an oven at 50 °C to obtain a CaCl2 melt liquid, slowly add the CaCl2 melt liquid into the COF / PAE composite carrier prepared in step (2) in a vacuum environment, and stir for 30 min in the vacuum environment. Dry the obtained composite material in a vacuum drying oven at 30 °C for 5 h to obtain a CaCl2·6H2O / COF / PAE composite phase change material. Measure the mass of the COF / PAE composite carrier before the CaCl2 melt liquid is added, denoted as m1, and measure the mass of the final CaCl2·6H2O / COF / PAE composite phase change material, denoted as m2. The mass fraction w of CaCl2·6H2O in the CaCl2·6H2O / COF / PAE composite phase change material is calculated by the formula w = ((m2-m1) / m2)×100%, which is 50% (the same below).

[0043] Example 2

[0044] Step (2.2): Take a certain mass of the polyacrylate porous material (PAE) prepared in step (1) and add it to the organic ligand dispersion liquid prepared in step (2.1) to obtain a mixed dispersion liquid, so that the mass fraction of the polyacrylate porous material in the mixed dispersion liquid is 30%; the remaining steps are the same as in Example 1.

[0045] Example 3

[0046] Step (2.2): Take a certain mass of the polyacrylate porous material (PAE) prepared in step (1) and add it to the organic ligand dispersion liquid prepared in step (2.1) to obtain a mixed dispersion liquid, so that the mass fraction of the polyacrylate porous material in the mixed dispersion liquid is 35%; the remaining steps are the same as in Example 1.

[0047] Example 4

[0048] The mass of CaCl2·6H2O in step (3) is 0.35 g, and the remaining steps are the same as in Example 1. According to the calculation method of Example 1, the mass fraction of CaCl2·6H2O in the CaCl2·6H2O / COF / PAE composite phase change material of this example is 40%.

[0049] Example 5

[0050] The mass of CaCl2·6H2O in step (3) is 0.45 g, and the remaining steps are the same as in Example 2. According to the calculation method of Example 1, the mass fraction of CaCl2·6H2O in the CaCl2·6H2O / COF / PAE composite phase change material of this example is 48%.

[0051] Example 6

[0052] The mass of CaCl2·6H2O in step (3) is 0.6 g, and the remaining steps are the same as those in Example 3. According to the calculation method in Example 1, the mass fraction of CaCl2·6H2O in the CaCl2·6H2O / COF / PAE composite phase change material in this example is 55%.

[0053] Figure 1 is a mechanism diagram of the preparation of the CaCl2·6H2O / COF / PAE composite phase change material.

[0054] Figure 2 is a SEM image of the COF / PAE composite carrier prepared in Example 1, and it can be seen from Figure 2 that the prepared COF / PAE composite carrier has a uniform spherical structure, and the COF material is uniformly distributed on the surface and voids of the PAE.

[0055] Figure 3 is a SEM image of the CaCl2·6H2O / COF / PAE composite phase change material prepared in Example 1, and it can be seen that CaCl2·6H2O is uniformly loaded inside and on the surface of the COF / PAE composite carrier, effectively realizing the encapsulation of the COF / PAE on the CaCl2·6H2O phase change material.

[0056] Figure 4 is a DSC graph of the CaCl2·6H2O / COF / PAE composite phase change material prepared in Example 1, and it can be seen that the CaCl2·6H2O / COF / PAE composite material exhibits a decrease in supercooling degree compared to single CaCl2·6H2O, i.e., the difference ΔT between the melting temperature and the crystallization temperature is reduced. The crystallization temperature of CaCl2·6H2O is 19 ℃, the melting temperature is 34 ℃, and the difference ΔT between the melting temperature and the crystallization temperature is 15 ℃. The crystallization temperature of the CaCl2·6H2O / COF / PAE composite phase change material is about 22 ℃, the melting temperature is 32 ℃, and the difference ΔT between the melting temperature and the crystallization temperature is 10 ℃. The supercooling degree of the CaCl2·6H2O / COF / PAE composite phase change material is reduced by 5 ℃ compared to single CaCl2·6H2O, which indicates that the COF / PAE composite carrier effectively reduces the supercooling phenomenon of CaCl2·6H2O, enhances the cycle stability and heat release efficiency of the phase change material, and makes it more suitable for stable thermal energy storage and release.

[0057] Figure 5DSC graph of CaCl2·6H2O / COF / PAE composite phase change material prepared in Example 1 after 100 cycles, it can be seen that compared with CaCl2·6H2O / COF / PAE composite phase change material without cycling, CaCl2·6H2O / COF / PAE composite phase change material after 100 cycles still has stable phase change temperature and good heat storage capacity, although the latent heat decreases slightly after 100 cycles, but the overall thermal performance of the material is still good, which is suitable for phase change energy storage material used in practical application.

[0058] Table 1 is the melting latent heat of CaCl2·6H2O / COF / PAE composite phase change material prepared in Example 1 after multiple cycles, it can be seen that after 100 cycles of CaCl2·6H2O / COF / PAE, the melting latent heat changes from 86.43 J / g at the beginning to 80.41 J / g, indicating that CaCl2·6H2O / COF / PAE composite phase change material has good thermal reliability.

[0059] Table 1. Melting latent heat of CaCl2·6H2O / COF / PAE composite phase change material after multiple cycles

[0060]

[0061] Figure 6 is the leakage situation of CaCl2·6H2O and CaCl2·6H2O / COF / PAE composite phase change material prepared in Example 1 after heating, wherein (a) represents CaCl2·6H2O without heating, (b) represents the situation of CaCl2·6H2O after heating at 40℃ for 30 min, (c) represents CaCl2·6H2O / COF / PAE composite phase change material without heating, and (d) represents the situation of CaCl2·6H2O / COF / PAE composite phase change material after heating at 40℃ for 30 min. It can be seen that compared with single CaCl2·6H2O, after being coated by COF / PAE porous structure, the leakage situation of CaCl2·6H2O / COF / PAE composite phase change material is significantly reduced, which indicates that the preparation method of the application can significantly reduce the liquid phase leakage problem of the composite phase change material after CaCl2·6H2O encapsulation treatment.

[0062] The above is only an embodiment of the application, and does not limit the application in any form, and the application can have other forms of embodiments according to the above structure and function, which will not be listed one by one. Therefore, any skilled person in the art, without departing from the scope of the technical scheme of the application, according to the technical essence of the application, any simple modification, equivalent change and modification of the above embodiments, still belongs to the scope of the technical scheme of the application.

Claims

1. A CaCl2-6H2O / COF / PAE composite phase change material, characterized in that: Composed of calcium chloride hexahydrate, organic framework COF material and polyacrylate porous material PAE, the polyacrylate porous material PAE is spherical particles, the organic framework COF material is distributed in the pores of the polyacrylate porous material PAE to form a COF / PAE composite material, the COF / PAE composite material is used as a carrier, and the calcium chloride hexahydrate phase change material is filled in the pores of the carrier to form a CaCl2·6H2O / COF / PAE composite phase change material.

2. A method for preparing CaCl2-6H2O / COF / PAE composite phase change material, characterized in that: It comprises the following steps: (1) preparing a polyacrylate porous material PAE Glycidyl methacrylate, trimethylolpropane triacrylate, PEG-PPG-PEG and benzoyl peroxide are dissolved in toluene in a mass ratio of 3:1:1:1 to form an oil phase by mixing uniformly at room temperature by using an ultrasonic chemical reaction kettle; Under stirring conditions, ethylenediamine and ethylene glycol are dissolved in water in a mass ratio of 7:9 to serve as an aqueous phase, and the total mass of ethylenediamine and ethylene glycol is 2:15 of the total mass of glycidyl methacrylate, trimethylolpropane triacrylate, PEG-PPG-PEG and benzoyl peroxide; the obtained oil phase is placed in an ice water bath, and then the aqueous phase is added dropwise into the oil phase, the volume ratio of the aqueous phase to the oil phase is 2:5, stirring is performed for 1 h to form a uniform and stable water-in-oil emulsion; nitrogen is introduced into the water-in-oil emulsion, then N,N-dimethylaniline is added into the water-in-oil emulsion, stirring is performed for 5-10 min, then ammonium persulfate and polyvinyl alcohol are added, stirring is performed for 1 h, then tetramethyl ethylenediamine is added dropwise into the reaction system, and stirring is performed at 55 °C and 400-500 rpm for 20-30 min to ensure that the emulsion dispersion of the reaction system is uniformly dispersed into droplets, at this time, the monomers in the reaction system begin to polymerize to form polyacrylate white solid particles, when the white solid particles are no longer generated, stirring is stopped, and the reaction is kept at 55 °C for 30-60 min, then the reaction mixture is filtered, and the filtrate is dried to obtain the polyacrylate porous material PAE; (2) preparing a COF / PAE composite carrier P-toluenesulfonic acid monohydrate and triformylphloroglucinol are added into deionized water to mix and stir to obtain an organic ligand dispersion liquid; the polyacrylate porous material PAE prepared in step (1) is added into the organic ligand dispersion liquid to stir uniformly to obtain a mixed dispersion liquid; diaminoanthraquinone is added into the mixed dispersion liquid, and after mixing, stirring is performed at 120 °C to make it fully react; after the reaction is completed, centrifugal separation is performed, and the product is dried at 65 °C to obtain the COF / PAE composite carrier; (3) preparing a CaCl2·6H2O / COF / PAE composite phase change material A certain mass of CaCl2·6H2O crystals is melted at 50 °C to obtain a CaCl2 molten liquid, the CaCl2 molten liquid is slowly added to the COF / PAE composite carrier in a vacuum environment, and stirring is performed in the vacuum environment for 30-40 min, and the obtained composite material is placed in a vacuum drying box for drying to obtain a CaCl2·6H2O / COF / PAE composite phase change material.

3. The preparation method of the CaCl2·6H2O / COF / PAE composite phase change material as described in claim 2, characterized in that: The mass ratio of ammonium persulfate to the total mass of glycidyl methacrylate, trimethylolpropane triacrylate, PEG-PPG-PEG and benzoyl peroxide in step (1) is 1:20, and the mass ratio of polyvinyl alcohol to the total mass of glycidyl methacrylate, trimethylolpropane triacrylate, PEG-PPG-PEG and benzoyl peroxide is 1:

5.

4. The preparation method of the CaCl2·6H2O / COF / PAE composite phase change material as described in claim 2, characterized in that: The mass ratio of p-toluenesulfonic acid monohydrate to tri-aldehyde phloroglucinol in step (2) is 23:6; the mass fraction of polyacrylate porous material PAE in the mixed dispersion liquid is 25-35 %.

5. The preparation method of the CaCl2·6H2O / COF / PAE composite phase change material as described in claim 2, characterized in that: The mass ratio of diaminanthraquinone to tri-aldehyde phloroglucinol in step (2) is 1:2.

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