Phase-change energy-storage temperature-regulating material and preparation method thereof

Abstract

The invention relates to the field of building materials, in particular to a phase change energy storage and temperature regulation material and a preparation method thereof.The phase change energy storage and temperature regulation material is prepared from, by weight, 70-120 parts of modified mesoporous silica, 30-50 parts of organic phase change materials, 0.5-3 parts of heat conduction enhancer and 0.25-3 parts of stabilizer; the modified mesoporous silica is obtained by modifying mesoporous silica through hydrophobic groups such as a benzene ring and long-chain alkyl; the heat-conducting reinforcing agent is obtained by modifying aluminum oxide through dodecyl glycoside; the modified mesoporous silica can significantly reduce the leakage rate of the organic phase change material, and when the modified mesoporous silica is combined with the heat conduction enhancer and other raw materials, thermal properties such as phase change latent heat, heat conductivity coefficient, specific heat capacity and the like of the phase change energy storage and temperature regulation material can be jointly improved; the phase-change energy-storage temperature-regulating material provided by the invention can be widely applied to the fields of building materials and the like.

Description

Technical Field

[0001] The present invention relates to the field of building materials, and particularly to a phase change energy storage temperature regulating material and a preparation method thereof. Background Art

[0002] With the increasing energy demand and the growing prominence of environmental problems, the development of efficient energy storage materials has become a research hotspot. Phase change materials (PCMs) can absorb and release a large amount of latent heat during the phase change process, enabling efficient energy storage and regulation, and thus have been widely studied. However, traditional phase change materials such as lauric acid have problems such as leakage and poor thermal conductivity during the solid-liquid phase change process, which limit their application scope. Existing technologies mostly improve them by encapsulating with porous materials or adding thermal conductive fillers, but their comprehensive performance still needs to be improved.

[0003] Chinese Patent with Application No. CN201310572630.1 discloses a self-regulating temperature phase change energy storage thermal insulation material for buildings, which includes the following raw materials in parts by weight: 20-40 parts of perlite, 15-25 parts of calcium powder, 5-10 parts of paraffin, 5-15 parts of white carbon black, 10-18 parts of inorganic salt mineral fiber, 4-8 parts of urea, and 6-12 parts of amide. The thermal insulation material prepared by this invention is green, environmentally friendly, non-toxic, and has excellent anti-aging performance, and is suitable for the thermal insulation and energy conservation of various buildings. However, perlite, as a lightweight porous substrate, has a high water absorption rate and is prone to water seepage and weight gain when in a humid environment for a long time. Components such as inorganic salt mineral fiber and white carbon black will also absorb water in a humid environment, resulting in a decline in material performance, which greatly limits its application in humid environments such as exterior wall thermal insulation. Chinese Patent with Application No. CN202011182160.4 discloses a microcapsule phase change energy storage material, its preparation method and application. The microcapsule phase change energy storage material provided by this invention consists of a core material and a shell material. The core material is a phase change material, and the shell material is a metal-based porous coordination polymer. The mass content of the core material is 70.5%-80.5%, and the mass content of the shell material is 19.5%-29.5%. This microcapsule phase change energy storage material integrates functions such as heat storage and temperature regulation, humidity regulation, and purification of harmful gases, and has multifunctionality. However, metal salt raw materials such as aluminum nitrate, gallium nitrate, and indium nitrate used in the preparation of the shell material are prone to nitrate residues. Such nitrogen-containing compounds will cause ecological risks such as water eutrophication after entering the ecological environment. In addition, the cost of using metal-based porous coordination polymer as the shell material is also relatively high, which further limits the application scope of this microcapsule phase change energy storage material.

[0004] Therefore, developing a new type of environmentally friendly phase change material with both high-efficiency thermal insulation, excellent energy storage performance and low cost to meet the needs of energy-saving systems such as building walls and floors is an urgent problem to be solved currently. Summary of the Invention

[0005] To solve the above problems, the present invention provides a phase change energy storage and temperature regulating material and a preparation method thereof. A phase change energy storage and temperature regulating material is prepared by using modified mesoporous silica to load organic phase change materials such as lauric acid. The phase change energy storage and temperature regulating material has a low leakage rate and excellent thermal properties such as phase change latent heat, thermal conductivity, and specific heat capacity, and can meet the diversified application requirements of energy storage and temperature regulating building materials.

[0006] The technical solution adopted by the present invention to achieve the above object is as follows:

[0007] A phase change energy storage and temperature regulating material, comprising the following raw materials in parts by weight: 70-120 parts of modified mesoporous silica, 30-50 parts of organic phase change material, 0.5-3 parts of thermal conductivity enhancer, and 0.25-3 parts of stabilizer. The preparation method of the modified mesoporous silica is as follows:

[0008] Step S1: Under the conditions of 95-105 °C and stirring, add silane coupling agent KH-560, phenylacetic acid, and triphenylphosphine to toluene, react for 2-4 h, and after cooling to room temperature, purify to obtain an intermediate. The structural formula of the intermediate is:

[0009]

[0010] Step S2: Under the conditions of 70-80 °C and stirring, add the intermediate, myristic acid, and concentrated sulfuric acid to absolute ethanol, react for 7-8 h, and after cooling to room temperature, purify to obtain a modified silane coupling agent. The structural formula of the modified silane coupling agent is:

[0011]

[0012] Step S3: First, dry the mesoporous silica, then disperse the dried mesoporous silica in absolute ethanol, then add the modified silane coupling agent, reflux and react at 70-80 °C for 7-8 h, and after naturally cooling to room temperature, purify to obtain modified mesoporous silica.

[0013] The synthesis route of the modified silane coupling agent is as follows:

[0014]

[0015] Furthermore, in step S1, the molar ratio of the silane coupling agent KH-560, phenylacetic acid, and triphenylphosphine is 1:1.05-1.2:0.01-0.1, and the addition amount of the silane coupling agent KH-560 in toluene is 0.08-0.12 g / mL.

[0016] Furthermore, in step S2, the mass ratio of the intermediate, myristic acid, and concentrated sulfuric acid is 1:0.3-0.4:0.003-0.01, and the addition amount of myristic acid in absolute ethanol is 0.05-0.1 g / mL.

[0017] Furthermore, the mass ratio of the dried mesoporous silica to the modified silane coupling agent in step S3 is 1.5 - 0.3:1, and the addition amount of the dried mesoporous silica in absolute ethanol is 0.06 - 0.08 g / mL.

[0018] Furthermore, the preparation method of the thermal conductivity enhancer is as follows: First, disperse alumina in absolute ethanol, then add dodecyl glycoside, and react at 60 - 80°C under stirring conditions for 2 - 4 h. After cooling to room temperature, purify to obtain it.

[0019] Furthermore, the mass ratio of the alumina to the dodecyl glycoside is 1:4 - 5, and the addition amount of the alumina in absolute ethanol is 0.1 - 0.15 g / mL.

[0020] Furthermore, the stabilizer is one or more of magnesium stearate, polyvinylpyrrolidone, and polyethylene glycol.

[0021] Furthermore, the organic phase change material is one or more of palmitic acid, myristic acid, and lauric acid.

[0022] The present invention also provides a preparation method of a phase change energy storage and temperature regulation material, comprising the following steps:

[0023] (1) Pour the molten organic phase change material and the modified mesoporous silica into a vacuum impregnation device in sequence, maintain the vacuum degree at 0.05 - 0.2 MPa, and perform impregnation treatment for 2 - 4 h to obtain an impregnated product;

[0024] (2) Add the thermal conductivity enhancer and the stabilizer to absolute ethanol and perform ultrasonic dispersion, then add them to the impregnated product obtained in step (1), stir at room temperature for 1 - 2 h, and after post-treatment, obtain the phase change energy storage and temperature regulation material.

[0025] The present invention has the following beneficial effects:

[0026] The present invention prepares modified mesoporous silica by means of chemical modification, then loads organic phase change materials such as lauric acid on the modified mesoporous silica, and then compound with heat conduction enhancers, stabilizers and other raw materials to obtain a phase change energy storage and temperature regulating material. This phase change energy storage and temperature regulating material has a low leakage rate and excellent thermal properties such as thermal conductivity, specific heat capacity, and phase change latent heat. The preparation of the modified mesoporous silica is first to carry out a ring-opening reaction between the epoxy group of the silane coupling agent KH-560 and the carboxyl group of phenylacetic acid to obtain an intermediate, and then carry out an esterification reaction between the hydroxyl group of the intermediate and the carboxyl group of myristic acid to obtain a modified silane coupling agent. Then, the modified silane coupling agent is used to hydrophobically modify the mesoporous silica. The molecular structure of this modified mesoporous silica contains benzene ring groups and long-chain alkyl groups. A large number of hydrophilic hydroxyl groups naturally exist on the surface of mesoporous silica, and there is a phenomenon of polarity mismatch with hydrophobic organic phase change materials such as lauric acid. The introduction of a strongly hydrophobic benzene ring group can form a "low surface energy barrier" on the surface of the modified mesoporous silica through surface modification, promoting the organic phase change material to tightly adsorb on the inner wall of the pore by van der Waals force, effectively preventing the leakage of organic phase change materials such as lauric acid during the phase change process, and also improving the hydrophobicity of the phase change energy storage and temperature regulating material, thereby improving the moisture-proof performance during the application of the composite material; in addition, the rigid structure of the benzene ring can increase the skeleton strength of the modified mesoporous silica, making it less likely to undergo structural deformation and collapse during the process of loading organic phase change materials and experiencing multiple phase changes, thus improving the stability of the entire phase change energy storage and temperature regulating material; the rigid structure of the benzene ring can also improve the heat conduction network of the modified mesoporous silica, combined with raw materials such as heat conduction enhancers, further enhancing the phase change latent heat, thermal conductivity and specific heat capacity of the phase change energy storage material, making the heat transfer more uniform and improving the temperature regulating efficiency. The introduction of long-chain alkyl groups can produce a synergistic effect with benzene ring groups, further improving the loading capacity of the modified mesoporous silica for organic phase change materials. Through surface modification, the surface of the modified mesoporous silica becomes more lipophilic, thus better adsorbing and loading organic phase change materials such as lauric acid, further reducing the leakage rate of the organic phase change material, and enabling the organic phase change materials such as lauric acid to more effectively exert their thermal properties in the phase change energy storage and temperature regulating material; the introduction of long-chain alkyl groups also helps to improve the thermal properties such as phase change latent heat, specific heat capacity and thermal conductivity of the phase change energy storage material. The long-chain alkyl groups can form a more compact network in the phase change energy storage material system, making the heat conduction in the material more efficient. During the heat transfer process, the molecular vibration of the long-chain alkyl groups can transfer heat to the surrounding organic phase change material molecules, thereby improving the thermal conductivity of the material. The heat conduction enhancer is prepared by modifying the surface of alumina particles with dodecyl glucoside, which improves the dispersibility and interfacial bonding force of alumina in the composite material system and further enhances the heat conduction performance in the composite material.

[0027] The modified mesoporous silica loaded with organic phase change materials such as lauric acid is compounded with raw materials such as thermal conductivity enhancers. The phase change latent heat, thermal conductivity, specific heat capacity and other key thermal properties of the prepared phase change energy storage and temperature regulating materials have been significantly improved. The increase in the phase change latent heat means that the material can store more heat, absorb or release a large amount of thermal energy when the temperature changes, and effectively buffer the environmental temperature fluctuations; the increase in the thermal conductivity makes the heat transfer more efficient, whether it is quickly absorbing heat during the heating stage or quickly releasing heat during the cooling stage, it can enhance the thermal response speed of the material; and the optimization of the specific heat capacity makes the material's own temperature change more gently when absorbing or releasing the same amount of heat, which helps to maintain the stability of the environmental temperature. The improvement of these properties makes the phase change energy storage and temperature regulating material have broad application potential in the field of building materials. Detailed implementation manners

[0028] The following will describe the technical solutions in the embodiments of the present application clearly and completely in conjunction with the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the scope of protection of the present application.

[0029] The raw materials used in the following embodiments are all ordinary commercially available products. The mesoporous silica has a particle size of 5-6 μm, a pore size of 5-20 nm, and a SiO2 content of ≥99.9%, and is purchased from Hangzhou Jikang New Materials Co., Ltd.; the alumina has a particle size of 30 nm and an Al2O3 content of ≥99.9%, and is purchased from Shanghai Maoguo Nano Technology Co., Ltd.; the polyvinylpyrrolidone has a particle size of 80 mesh and a product number of 005, and is purchased from Shandong Runhe Chemical Co., Ltd.; the polyethylene glycol is PEG400, with a density of 1.27 g / cm 3 , and is purchased from Jinan Xinke Chemical Co., Ltd.; the concentrated sulfuric acid has a concentration of 97.5% and is purchased from Maoming Xiongda Chemical Industry Co., Ltd.

[0030] Example 1

[0031] A phase change energy storage and temperature regulating material includes the following raw materials in parts by weight: 70 parts of modified mesoporous silica, 30 parts of organic phase change material, 0.5 part of thermal conductivity enhancer, and 0.25 part of stabilizer;

[0032] Among them, the stabilizer is magnesium stearate, and the organic phase change material is palmitic acid;

[0033] The preparation method of the modified mesoporous silica is as follows:

[0034] Step S1: Under the conditions of 95 °C and stirring, add silane coupling agent KH-560, phenylacetic acid, and triphenylphosphine into toluene, react for 4 h. After naturally cooling to room temperature, filter to obtain a filtrate, and then rotary evaporate the toluene from the filtrate at 60 °C to obtain an intermediate. The molar ratio of silane coupling agent KH-560, phenylacetic acid, and triphenylphosphine is 1:1.05:0.01, and the addition amount of silane coupling agent KH-560 in toluene is 0.08 g / mL;

[0035] Step S2: Under the conditions of 70 °C and stirring, add the intermediate, myristic acid, and concentrated sulfuric acid into absolute ethanol, react for 8 h. After naturally cooling to room temperature, filter to obtain a filtrate, and then rotary evaporate the absolute ethanol from the filtrate at 40 °C to obtain a modified silane coupling agent. The mass ratio of the intermediate, myristic acid, and concentrated sulfuric acid is 1:0.3:0.003, and the addition amount of myristic acid in absolute ethanol is 0.05 g / mL;

[0036] Step S3: First, vacuum dry the mesoporous silica at 120 °C for 2 h, then ultrasonically disperse the dried mesoporous silica in absolute ethanol. The ultrasonic power is 500 W and the ultrasonic time is 30 min. Then add the modified silane coupling agent and reflux at 70 °C for 8 h. After naturally cooling to room temperature, centrifuge and wash 3 times with absolute ethanol at 4000 rpm for 5 min each time. Then dry to constant weight in a vacuum drying oven at 60 °C, ball mill and screen to obtain modified mesoporous silica with a particle size not greater than 10 μm. The mass ratio of the dried mesoporous silica to the modified silane coupling agent is 1.5:1, and the addition amount of the dried mesoporous silica in absolute ethanol is 0.06 g / mL. Then carry out ball milling. When ball milling, zirconia balls are selected. The diameters of the large, medium, and small balls are 10 mm, 5 mm, and 1 mm respectively, the ratio of large, medium, and small balls is 3:4:3, the rotation speed is 500 r / min, the ball-to-material ratio is 10:1, and the ball milling time is 8 h. The modification grafting rate is 8.31%, and the modification grafting rate = (m 改性介孔二氧化硅 -m 干燥后的介孔二氧化硅 ) / m 干燥后的介孔二氧化硅 ×100%.

[0037] The preparation method of the thermal conductivity enhancer is as follows: First, disperse alumina in absolute ethanol by ultrasonic treatment. The ultrasonic power is 300 W and the ultrasonic time is 30 min. Then, add dodecyl glucoside and react under stirring at 60 °C for 4 h. After natural cooling to room temperature, successively centrifuge and wash with absolute ethanol and deionized water at 10,000 rpm for 10 min each. Then, dry in a vacuum drying oven at 60 °C until constant weight, and perform ball milling and sieving to obtain a thermal conductivity enhancer with a particle size not greater than 30 nm. The mass ratio of alumina to dodecyl glucoside is 1:4, the addition amount of alumina in absolute ethanol is 0.1 g / mL. When performing ball milling, zirconia balls are selected, and the diameters of the large, medium, and small balls are 10 mm, 5 mm, and 1 mm respectively. The ratio of large, medium, and small balls is 3:3:4, the rotation speed is 500 r / min, the ball-to-material ratio is 8:1, the ball milling time is 10 h, and the grafting rate is 10.01%. The modified grafting rate = (m 导热增强剂 -m 氧化铝 ) / m 氧化铝 × 100%.

[0038] The synthesis route of the modified silane coupling agent is as follows:

[0039]

[0040] The NMR results of the intermediate are as follows: 1H NMR (300 MHz, acetone-d6) δ 7.20 - 7.31 (m, 5H), 5.76 (s, 1H), 4.05 - 4.42 (m, 3H), 3.71 (s, 2H), 3.53 - 3.66 (m, 10H), 3.29 - 3.42 (m, 3H), 1.37 - 1.47 (m, 2H), 0.56 (t, 2H);

[0041] The NMR results of the modified silane coupling agent are as follows: 1H NMR (300 MHz, acetone-d6) δ 7.21 - 7.31 (m, 5H), 5.43 - 5.49 (m, 1H), 4.14 - 4.45 (m, 2H), 3.68 - 3.74 (m, 3H), 3.45 - 3.55 (m, 10H), 3.33 - 3.36 (m, 2H), 2.35 (t, 2H), 1.65 - 1.68 (m, 2H), 1.32 - 1.43 (m, 4H), 1.24 - 1.30 (m, 18H), 0.88 (t, 3H), 0.56 (t, 2H).

[0042] The present invention also provides a preparation method of a phase change energy storage and temperature regulating material, including the following steps:

[0043] (1) Pour molten palmitic acid and modified mesoporous silica at 70 °C into a vacuum impregnation device in sequence, keep the vacuum degree at 0.05 - 0.2 MPa, and perform impregnation treatment for 2 h to obtain an impregnated product;

[0044] (2) Add the thermal conductivity enhancer and stabilizer into absolute ethanol and disperse them by ultrasonic treatment. The ultrasonic power is 300 W and the ultrasonic time is 30 min. Then add the mixture into the impregnation product obtained in step (1), stir for 1 h at room temperature, rotary evaporate to remove absolute ethanol at 40 °C, vacuum dry at 110 °C until constant weight, and then carry out ball milling. When carrying out ball milling, zirconia balls are selected. The diameters of large, medium and small balls are 10 mm, 5 mm and 1 mm respectively. The ratio of large, medium and small balls is 3:3:4, the rotation speed is 500 r / min, the ball-to-material ratio is 8:1, and the ball milling time is 12 h. Then sieve to obtain a powder with a particle size not greater than 50 nm, namely the phase change energy storage and temperature regulation material.

[0045] Example 2

[0046] A phase change energy storage and temperature regulation material, comprising the following raw materials in parts by weight: 120 parts of modified mesoporous silica, 50 parts of organic phase change material, 3 parts of thermal conductivity enhancer, and 3 parts of stabilizer;

[0047] The stabilizer is polyvinylpyrrolidone, and the organic phase change material is myristic acid;

[0048] The preparation method of the modified mesoporous silica is as follows:

[0049] Step S1: Add silane coupling agent KH-560, phenylacetic acid, and triphenylphosphine into toluene at 105 °C under stirring conditions, react for 2 h, naturally cool to room temperature, filter to obtain a filtrate, and then rotary evaporate to remove toluene from the filtrate at 60 °C to obtain an intermediate. The molar ratio of silane coupling agent KH-560, phenylacetic acid, and triphenylphosphine is 1:1.2:0.1, and the addition amount of silane coupling agent KH-560 in toluene is 0.12 g / mL;

[0050] Step S2: Add the intermediate, myristic acid, and concentrated sulfuric acid into absolute ethanol at 80 °C under stirring conditions, react for 7 h, naturally cool to room temperature, filter to obtain a filtrate, and then rotary evaporate to remove absolute ethanol from the filtrate at 40 °C to obtain a modified silane coupling agent. The mass ratio of the intermediate, myristic acid, and concentrated sulfuric acid is 1:0.4:0.01, and the addition amount of myristic acid in absolute ethanol is 0.1 g / mL;

[0051] Step S3: First, vacuum-dry the mesoporous silica at 120 °C for 2 h. Then, ultrasonically disperse the dried mesoporous silica in absolute ethanol with an ultrasonic power of 500 W and an ultrasonic time of 30 min. Next, add the modified silane coupling agent and reflux at 80 °C for 7 h. After natural cooling to room temperature, centrifuge and wash three times with absolute ethanol at 4000 rpm for 5 min each time. Then, dry in a vacuum drying oven at 60 °C until constant weight, ball-mill and screen to obtain modified mesoporous silica with a particle size not greater than 10 μm. The mass ratio of the dried mesoporous silica to the modified silane coupling agent is 0.3:1, and the addition amount of the dried mesoporous silica in absolute ethanol is 0.08 g / mL. Then, perform ball-milling. When ball-milling, use zirconia balls with large, medium, and small ball diameters of 10 mm, 5 mm, and 1 mm respectively, a large, medium, and small ball ratio of 3:4:3, a rotation speed of 500 r / min, a ball-to-material ratio of 10:1, and a ball-milling time of 8 h. The modified grafting rate is 7.89%, and the modified grafting rate = (m 改性介孔二氧化硅 -m 干燥后的介孔二氧化硅 ) / m 干燥后的介孔二氧化硅 × 100%.

[0052] The preparation method of the thermal conductivity enhancer is as follows: First, ultrasonically disperse alumina in absolute ethanol with an ultrasonic power of 300 W and an ultrasonic time of 30 min. Then, add dodecyl glucoside and react at 80 °C under stirring conditions for 2 h. After natural cooling to room temperature, centrifuge and wash successively with absolute ethanol and deionized water at 10000 rpm for 10 min each time. Then, dry in a vacuum drying oven at 60 °C until constant weight, ball-mill and screen to obtain a thermal conductivity enhancer with a particle size not greater than 30 nm. The mass ratio of alumina to dodecyl glucoside is 1:5, the addition amount of alumina in absolute ethanol is 0.15 g / mL. When ball-milling, use zirconia balls with large, medium, and small ball diameters of 10 mm, 5 mm, and 1 mm respectively, a large, medium, and small ball ratio of 3:3:4, a rotation speed of 500 r / min, a ball-to-material ratio of 8:1, and a ball-milling time of 10 h. The grafting rate is 9.97%, and the modified grafting rate = (m 导热增强剂 -m 氧化铝 ) / m 氧化铝 × 100%.

[0053] The present invention also provides a preparation method of a phase change energy storage and temperature regulation material, comprising the following steps:

[0054] (1) Pour the myristic acid melted at 60 °C and the modified mesoporous silica into a vacuum impregnation device in sequence, maintain the vacuum degree at 0.05 - 0.2 MPa, and perform impregnation treatment for 4 h to obtain an impregnated product;

[0055] (2) Add the thermal conductivity enhancer and stabilizer into absolute ethanol and disperse them by ultrasonic wave. The ultrasonic power is 300 W and the ultrasonic time is 30 min. Then add the mixture into the impregnation product obtained in step (1), stir at room temperature for 2 h, rotary evaporate to remove absolute ethanol at 40 °C, vacuum dry at 110 °C until constant weight, and then carry out ball milling. When carrying out ball milling, zirconia balls are selected. The diameters of large, medium and small balls are 10 mm, 5 mm and 1 mm respectively. The ratio of large, medium and small balls is 3:3:4, the rotation speed is 500 r / min, the ball-to-material ratio is 8:1, and the ball milling time is 12 h. Then sieve to obtain a powder with a particle size not greater than 50 nm, namely the phase change energy storage and temperature regulation material.

[0056] Example 3

[0057] A phase change energy storage and temperature regulation material, comprising the following raw materials in parts by weight: 100 parts of modified mesoporous silica, 40 parts of organic phase change material, 2 parts of thermal conductivity enhancer, and 1 part of stabilizer;

[0058] The stabilizer is polyethylene glycol, and the organic phase change material is lauric acid;

[0059] The preparation method of the modified mesoporous silica is as follows:

[0060] Step S1: Add silane coupling agent KH-560, phenylacetic acid and triphenylphosphine into toluene at 100 °C under stirring conditions, react for 3 h, naturally cool to room temperature, filter to obtain a filtrate, and then rotary evaporate to remove toluene from the filtrate at 60 °C to obtain an intermediate. The molar ratio of silane coupling agent KH-560, phenylacetic acid and triphenylphosphine is 1:1.1:0.05, and the addition amount of silane coupling agent KH-560 in toluene is 0.1 g / mL;

[0061] Step S2: Add the intermediate, myristic acid and concentrated sulfuric acid into absolute ethanol at 75 °C under stirring conditions, react for 7.5 h, naturally cool to room temperature, filter to obtain a filtrate, and then rotary evaporate to remove absolute ethanol from the filtrate at 40 °C to obtain a modified silane coupling agent. The mass ratio of the intermediate, myristic acid and concentrated sulfuric acid is 1:0.35:0.005, and the addition amount of myristic acid in absolute ethanol is 0.08 g / mL;

[0062] Step S3: First, vacuum-dry the mesoporous silica at 120 °C for 2 h. Then, ultrasonically disperse the dried mesoporous silica in absolute ethanol with an ultrasonic power of 500 W and an ultrasonic time of 30 min. Next, add the modified silane coupling agent and reflux at 75 °C for 7.5 h. After natural cooling to room temperature, centrifuge and wash three times with absolute ethanol at 4000 rpm for 5 min each time. Then, dry in a vacuum drying oven at 60 °C until constant weight, and ball-mill and screen to obtain modified mesoporous silica with a particle size not greater than 10 μm. The mass ratio of the dried mesoporous silica to the modified silane coupling agent is 1:1, and the addition amount of the dried mesoporous silica in absolute ethanol is 0.07 g / mL. Then, perform ball-milling. When ball-milling, use zirconia balls with large, medium, and small ball diameters of 10 mm, 5 mm, and 1 mm respectively, a large, medium, and small ball ratio of 3:4:3, a rotation speed of 500 r / min, a ball-to-material ratio of 10:1, and a ball-milling time of 8 h. The modified grafting rate is 8.19%, and the modified grafting rate = (m 改性介孔二氧化硅 -m 干燥后的介孔二氧化硅 ) / m 干燥后的介孔二氧化硅 × 100%.

[0063] The preparation method of the thermal conductivity enhancer is as follows: First, ultrasonically disperse alumina in absolute ethanol with an ultrasonic power of 300 W and an ultrasonic time of 30 min. Then, add dodecyl glucoside and react at 70 °C under stirring conditions for 3 h. After natural cooling to room temperature, centrifuge and wash successively with absolute ethanol and deionized water at 10000 rpm for 10 min each time. Then, dry in a vacuum drying oven at 60 °C until constant weight, and ball-mill and screen to obtain a thermal conductivity enhancer with a particle size not greater than 30 nm. The mass ratio of alumina to dodecyl glucoside is 1:4.5, the addition amount of alumina in absolute ethanol is 0.13 g / mL. When ball-milling, use zirconia balls with large, medium, and small ball diameters of 10 mm, 5 mm, and 1 mm respectively, a large, medium, and small ball ratio of 3:3:4, a rotation speed of 500 r / min, a ball-to-material ratio of 8:1, and a ball-milling time of 10 h. The grafting rate is 10.37%, and the modified grafting rate = (m 导热增强剂 -m 氧化铝 ) / m 氧化铝 × 100%.

[0064] The present invention also provides a preparation method of a phase change energy storage and temperature regulation material, comprising the following steps:

[0065] (1) Pour the lauric acid melted at 50 °C and the modified mesoporous silica into a vacuum impregnation device in sequence, keep the vacuum degree at 0.05 - 0.2 MPa, and perform impregnation treatment for 3 h to obtain an impregnated product;

[0066] (2) Add the thermal conductivity enhancer and stabilizer into absolute ethanol and disperse them by ultrasonic treatment. The ultrasonic power is 300 W and the ultrasonic time is 30 min. Then add the mixture into the impregnation product obtained in step (1), stir for 1.5 h at room temperature, rotary evaporate to remove absolute ethanol at 40 °C, vacuum dry at 110 °C until constant weight, and then carry out ball milling. When ball milling, zirconia balls are selected. The diameters of the large, medium and small balls are 10 mm, 5 mm and 1 mm respectively. The ratio of large, medium and small balls is 3:3:4, the rotation speed is 500 r / min, the ball-to-material ratio is 8:1, and the ball milling time is 12 h. Then sieve to obtain a powder with a particle size not greater than 50 nm, namely the phase change energy storage and temperature regulation material.

[0067] Comparative Example 1

[0068] A phase change energy storage and temperature regulation material, comprising the following raw materials in parts by weight: 50 parts of modified mesoporous silica, 60 parts of organic phase change material, 0.1 part of thermal conductivity enhancer, and 0.1 part of stabilizer;

[0069] Wherein the stabilizer is polyethylene glycol and the organic phase change material is lauric acid;

[0070] The preparation method of the modified mesoporous silica is as follows:

[0071] Step S1: Add silane coupling agent KH-560, phenylacetic acid and triphenylphosphine into toluene at 80 °C under stirring conditions and react for 1 h. After naturally cooling to room temperature, filter to obtain a filtrate, and then rotary evaporate to remove toluene from the filtrate at 60 °C to obtain an intermediate. The molar ratio of silane coupling agent KH-560, phenylacetic acid and triphenylphosphine is 1:1.1:0.05, and the addition amount of silane coupling agent KH-560 in toluene is 0.1 g / mL;

[0072] Step S2: Add the intermediate, myristic acid and concentrated sulfuric acid into absolute ethanol at 50 °C under stirring conditions and react for 3 h. After naturally cooling to room temperature, filter to obtain a filtrate, and then rotary evaporate to remove absolute ethanol from the filtrate at 40 °C to obtain a modified silane coupling agent. The mass ratio of the intermediate, myristic acid and concentrated sulfuric acid is 1:0.35:0.005, and the addition amount of myristic acid in absolute ethanol is 0.08 g / mL;

[0073] Step S3: First, vacuum-dry the mesoporous silica at 120 °C for 2 h, then ultrasonically disperse the dried mesoporous silica in absolute ethanol with an ultrasonic power of 500 W and an ultrasonic time of 30 min. Then add the modified silane coupling agent and reflux at room temperature for 7 h, followed by centrifugal washing with absolute ethanol 3 times at 4000 rpm for 5 min each time. Then dry in a vacuum drying oven at 60 °C until constant weight, and ball-mill and sieve to obtain modified mesoporous silica with a particle size not greater than 10 μm. The mass ratio of the dried mesoporous silica to the modified silane coupling agent is 1:1, and the addition amount of the dried mesoporous silica in absolute ethanol is 0.07 g / mL. Then perform ball-milling. When ball-milling, use zirconia balls with large, medium, and small ball diameters of 10 mm, 5 mm, and 1 mm respectively, a large, medium, and small ball ratio of 3:4:3, a rotation speed of 500 r / min, a ball-to-material ratio of 10:1, and a ball-milling time of 8 h.

[0074] The preparation method of the thermal conductivity enhancer is as follows: First, ultrasonically disperse alumina in absolute ethanol with an ultrasonic power of 300 W and an ultrasonic time of 30 min. Then add dodecyl glucoside and react at room temperature under stirring conditions for 3 h. Then centrifuge and wash successively with absolute ethanol and deionized water at 10000 rpm for 10 min each time. Then dry in a vacuum drying oven at 60 °C until constant weight, and ball-mill and sieve to obtain a thermal conductivity enhancer with a particle size not greater than 30 nm. The mass ratio of alumina to dodecyl glucoside is 1:4.5, the addition amount of alumina in absolute ethanol is 0.13 g / mL. When ball-milling, use zirconia balls with large, medium, and small ball diameters of 10 mm, 5 mm, and 1 mm respectively, a large, medium, and small ball ratio of 3:3:4, a rotation speed of 500 r / min, a ball-to-material ratio of 8:1, and a ball-milling time of 10 h.

[0075] The present invention also provides a preparation method of a phase change energy storage and temperature regulation material, comprising the following steps:

[0076] (1) Pour the lauric acid melted at 50 °C and the modified mesoporous silica into a vacuum impregnation device in sequence, keep the vacuum degree at 0.05 - 0.2 MPa, and perform impregnation treatment for 3 h to obtain an impregnated product;

[0077] (2) Add the thermal conductivity enhancer and stabilizer to absolute ethanol and disperse them by ultrasonic treatment. The ultrasonic power is 300 W and the ultrasonic time is 30 min. Then add the mixture to the impregnation product obtained in step (1), stir at room temperature for 1.5 h, rotary evaporate to remove absolute ethanol at 40 °C, vacuum dry at 110 °C until constant weight, and then perform ball milling. When performing ball milling, zirconia balls are selected. The diameters of the large, medium, and small balls are 10 mm, 5 mm, and 1 mm respectively. The ratio of large, medium, and small balls is 3:3:4, the rotation speed is 500 r / min, the ball-to-material ratio is 8:1, and the ball milling time is 12 h. Then sieve to obtain a powder with a particle size not greater than 50 nm, namely the phase change energy storage and temperature regulation material.

[0078] Comparative Example 2

[0079] A phase change energy storage and temperature regulation material, comprising the following raw materials in parts by weight: 100 parts of modified mesoporous silica, 40 parts of organic phase change material, 2 parts of thermal conductivity enhancer, and 1 part of stabilizer;

[0080] Wherein the stabilizer is polyethylene glycol and the organic phase change material is lauric acid;

[0081] The preparation method of the modified mesoporous silica is as follows:

[0082] Step S1: Add silane coupling agent KH-560, phenylacetic acid, and triphenylphosphine to toluene at 100 °C under stirring conditions and react for 3 h. After naturally cooling to room temperature, filter to obtain a filtrate, and then rotary evaporate the filtrate to remove toluene at 60 °C to obtain a modified silane coupling agent. The molar ratio of silane coupling agent KH-560, phenylacetic acid, and triphenylphosphine is 1:1.1:0.05, and the addition amount of silane coupling agent KH-560 in toluene is 0.1 g / mL;

[0083] Step S2: First vacuum dry the mesoporous silica at 120 °C for 2 h, then ultrasonically disperse the dried mesoporous silica in absolute ethanol. The ultrasonic power is 500 W and the ultrasonic time is 30 min. Then add the modified silane coupling agent and reflux at 75 °C for 7.5 h. After naturally cooling to room temperature, centrifuge and wash 3 times with absolute ethanol at 4000 rpm for 5 min each time, and then dry in a vacuum drying oven at 60 °C until constant weight to obtain modified mesoporous silica. The mass ratio of the dried mesoporous silica to the modified silane coupling agent is 1:1, and the addition amount of the dried mesoporous silica in absolute ethanol is 0.07 g / mL.

[0084] The preparation method of the thermal conductivity enhancer and the preparation method of the phase change energy storage and temperature regulation material are the same as those in Example 3.

[0085] Comparative Example 3

[0086] A phase change energy storage and temperature regulating material, comprising the following raw materials in parts by weight: 100 parts of mesoporous silica, 40 parts of organic phase change material, 2 parts of thermal conductivity enhancer, and 1 part of stabilizer;

[0087] The stabilizer is polyethylene glycol, and the organic phase change material is lauric acid;

[0088] The preparation method of the thermal conductivity enhancer and the preparation method of the phase change energy storage and temperature regulating material are the same as those in Example 3.

[0089] Comparative Example 4

[0090] A phase change energy storage and temperature regulating material, comprising the following raw materials in parts by weight: 100 parts of mesoporous silica, 40 parts of organic phase change material, 2 parts of thermal conductivity enhancer, and 1 part of stabilizer;

[0091] The stabilizer is polyethylene glycol, the organic phase change material is lauric acid, and the thermal conductivity enhancer is alumina;

[0092] The preparation method of the phase change energy storage and temperature regulating material is the same as that in Example 3.

[0093] Leakage rate test: Place the sample in a constant temperature drying oven at 60 °C for 20 min, then take it out and place it at room temperature for 20 min, which is one cycle. Repeat this cycle 100 times, weigh the change in the mass of the bulk sample before and after, and calculate the leakage rate of the material. The leakage rate = (m1 - m2) / m1, where m1 is the mass of the sample before 50 cycles and m2 is the mass of the sample after 50 cycles.

[0094] Thermal performance test: Conduct thermal performance tests in accordance with the requirements in JC / T 2111-2012 "Test Method for Phase Change Temperature Regulation Performance of Building Materials", including phase change latent heat and specific heat capacity.

[0095] Thermal conductivity test: Conduct thermal conductivity tests in accordance with the requirements in GB / T 10297-2015 "Hot Wire Method for Measuring Thermal Conductivity of Non-Metallic Solid Materials".

[0096] The specific test data can be seen from Table 1.

[0097] Table 1 Performance test results

[0098] Sample Leakage rate % Latent heat of phase change (J / g) Specific heat capacity (J / (g·K)) Thermal conductivity (W / (m·k)) Example 1 2.75 249 2.14 0.230 Example 2 2.68 250 2.13 0.221 Example 3 2.71 247 2.09 0.219 Comparative example 1 4.59 245 1.98 0.194 Comparative example 2 4.94 243 1.86 0.162 Comparative example 3 5.77 240 1.80 0.155 Comparative example 4 5.71 239 1.81 0.157

[0099] As can be seen from Table 1, the leakage rates of the phase change energy storage and temperature regulation materials prepared in Examples 1-3 are relatively low. Therefore, the long-term cycle stability is significantly better than that of the phase change energy storage and temperature regulation materials prepared in Comparative Examples 1-4. Compared with Comparative Examples 1-4, the phase change energy storage and temperature regulation materials prepared in Examples 1-3 have a higher phase change latent heat and can more effectively achieve energy storage and temperature regulation. In addition, the specific heat capacity of the phase change energy storage and temperature regulation materials prepared in Examples 1-3 is also relatively high, so the ability to store and release heat is strong. The thermal conductivity of the phase change energy storage and temperature regulation materials prepared in Examples 1-3 has been significantly improved compared with Comparative Examples 1-4, so that heat exchange can be carried out more quickly, and the efficiency of phase change energy storage and temperature regulation can be improved.

[0100] Although the embodiments of the present application have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principle and spirit of the present application. The scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A phase change energy storage and temperature regulating material, characterized in that, It comprises raw materials in the following parts by weight: 70 - 120 parts of modified mesoporous silica, 30 - 50 parts of organic phase change material, 0.5 - 3 parts of thermal conductivity enhancer, and 0.25 - 3 parts of stabilizer. The preparation method of the modified mesoporous silica is as follows: Step S1: Under the conditions of 95 - 105 °C and stirring, add silane coupling agent KH-560, phenylacetic acid, and triphenylphosphine into toluene, react for 2 - 4 h, and after cooling to room temperature, purify to obtain an intermediate; Step S2: Under the conditions of 70 - 80 °C and stirring, add the intermediate, myristic acid, and concentrated sulfuric acid into absolute ethanol, react for 7 - 8 h, and after cooling to room temperature, purify to obtain a modified silane coupling agent; Step S3: First, dry the mesoporous silica, then disperse the dried mesoporous silica in absolute ethanol, then add the modified silane coupling agent, reflux and react at 70 - 80 °C for 7 - 8 h, and after natural cooling to room temperature, purify to obtain the modified mesoporous silica.

2. The phase change energy storage and temperature regulating material according to claim 1, wherein In Step S1, the molar ratio of the silane coupling agent KH-560, phenylacetic acid, and triphenylphosphine is 1:1.05 - 1.2:0.01 - 0.1, and the addition amount of the silane coupling agent KH-560 in toluene is 0.08 - 0.12 g / mL.

3. The phase change energy storage and temperature regulating material according to claim 1, wherein In Step S2, the mass ratio of the intermediate, myristic acid, and concentrated sulfuric acid is 1:0.3 - 0.4:0.003 - 0.01, and the addition amount of myristic acid in absolute ethanol is 0.05 - 0.1 g / mL.

4. The phase change energy storage and temperature regulating material according to claim 1, characterized in that, In Step S3, the mass ratio of the dried mesoporous silica to the modified silane coupling agent is 1.5 - 0.3:1, and the addition amount of the dried mesoporous silica in absolute ethanol is 0.06 - 0.08 g / mL.

5. The phase change energy storage and temperature regulating material according to claim 1, wherein The preparation method of the thermal conductivity enhancer is: First, disperse alumina in absolute ethanol, then add dodecyl glucoside, and react at 60 - 80 °C under stirring conditions for 2 - 4 h, and after cooling to room temperature, purify to obtain it.

6. The phase change energy storage and temperature regulating material according to claim 5, characterized in that The mass ratio of the alumina to the dodecyl glucoside is 1:4 - 5, and the addition amount of alumina in absolute ethanol is 0.1 - 0.15 g / mL.

7. The phase change energy storage and temperature regulating material according to claim 1, wherein The stabilizer is one or more of magnesium stearate, polyvinylpyrrolidone, and polyethylene glycol.

8. The phase change energy storage and temperature regulating material according to claim 1, wherein The organic phase change material is one or more of palmitic acid, myristic acid, and lauric acid.

9. The preparation method of the phase change energy storage and temperature regulating material according to any one of claims 1 to 8, characterized in that, It includes the following steps: (1) Pour the molten organic phase change material and the modified mesoporous silica into a vacuum impregnation device in sequence, keep the vacuum degree at 0.05 - 0.2 MPa, and carry out impregnation treatment for 2 - 4 h to obtain an impregnated product; (2) Add the thermal conductivity enhancer and the stabilizer into absolute ethanol and carry out ultrasonic dispersion, then add them into the impregnated product obtained in step (1), stir at room temperature for 1 - 2 h, and after post-treatment, obtain the phase change energy storage and temperature regulation material.

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