A method for preparing and applying a shaped organic / inorganic composite phase change material

Abstract

A method for preparing and applying a shaped organic / inorganic composite phase change material (CPCM) is disclosed, belonging to the field of phase change energy storage technology. The CPCM comprises 50-70 wt% inorganic solid-liquid CPCM, 5-30 wt% organic solid-liquid CPCM, 5-15 wt% emulsifier and thickener, and 10-30 wt% porous support material. The inorganic solid-liquid CPCM is a hydrated inorganic salt-based CPCM, the organic solid-liquid CPCM is an organic acid ester or long-chain alkane-based CPCM, and the emulsifier and thickener are ionic cellulose gums. These three components are assembled under supramolecular forces and uniformly composited with the porous adsorbent material. The prepared CPCM exhibits a high phase change enthalpy and good cycling stability. Furthermore, the CPCM demonstrates excellent building thermal management performance, making it highly suitable for large-scale application in future building thermal management.

Description

Technical Field

[0001] This invention relates to a method for preparing and applying a heat-insulating shaped organic / inorganic composite phase change material, which belongs to the field of phase change energy storage technology. Background Technology

[0002] With the continuous improvement of global population and living standards, energy demand is constantly increasing. Phase change energy storage materials have advantages such as large latent heat of phase change and small temperature change during phase change. Applying phase change energy storage materials to various energy-saving fields can effectively reduce energy consumption and achieve the goal of energy conservation.

[0003] However, currently reported phase change materials (PCMs) inevitably require the addition of large amounts of flame retardants, nucleating agents, and thickeners to address the inherent defects of organic or inorganic PCMs (such as supercooling, phase separation, and flammability). This undoubtedly significantly reduces the phase transition enthalpy of the composite PCMs. Furthermore, because solid-liquid PCMs generate a liquid state during phase transition, they pose a risk of leakage. Although researchers have used porous materials such as diatomaceous earth, perlite, and kaolinite for encapsulation to prevent leakage, the high cost and required high mass fraction significantly reduce the phase transition enthalpy, thereby diminishing their thermal management capabilities. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a type of shaped organic / inorganic composite phase change material, its preparation method, and its applications. This addresses the technical issues of flammability in organic solid-liquid phase change materials, supercooling and phase separation in inorganic solid-liquid phase change materials, as well as leakage and low enthalpy in solid-liquid phase change materials. The material uses high-enthalpy disodium hydrogen phosphate dodecahydrate (DHPD), sodium carbonate decahydrate (SCD), and methyl palmitate (MP) as the phase change matrix, sodium carboxymethyl cellulose (CMC) as an emulsifier and thickener, and silica aerogel as a porous supporting framework, forming a shaped organic / inorganic composite phase change material, which is then applied in building thermal management. This material exhibits good flame retardancy, low supercooling, and no phase separation. It also possesses good shape stability, a high phase change enthalpy, and good cycling stability. Furthermore, this CPCM demonstrates excellent building thermal management performance. The material has a simple synthesis process, is easy to apply, and has broad application prospects.

[0005] A high-enthalpy-value shaped organic / inorganic composite phase change material with heat-insulating function is disclosed. The organic / inorganic solid-liquid phase change material, by mass percentage, comprises 50-80 wt% inorganic solid-liquid phase change material, 5-30 wt% organic solid-liquid phase change material, 5-17 wt% thickener, and 10-30 wt% porous support material. The inorganic solid-liquid phase change material is a hydrated inorganic salt phase change material, the organic solid-liquid phase change material is an organic acid ester or long-chain alkane phase change material, and the emulsifier / thickener is an ionic cellulose gum. These three components are assembled under supramolecular forces and uniformly composited with the porous adsorbent material.

[0006] Preferably, the organic / inorganic composite solid-liquid phase change material is composed of 64-70 wt% inorganic solid-liquid phase change material, 6.4 wt% organic solid-liquid phase change material, 9.6 wt% thickener, and 20-25 wt% porous support material by mass percentage. The phase change material can maintain a uniform and stable shape, has low undercooling, and meets thermal management requirements.

[0007] More preferably, the organic-inorganic composite solid-liquid phase change material is composed of 64 wt% inorganic solid-liquid phase change material, 6.4 wt% organic solid-liquid phase change material, 9.6 wt% thickener and 20 wt% porous support material by mass percentage.

[0008] Preferably, the inorganic solid-liquid phase change material is one to three of the following: sodium acetate trihydrate, barium hydroxide octahydrate, magnesium chloride hexahydrate, calcium chloride hexahydrate, magnesium sulfate heptahydrate, sodium carbonate decahydrate, disodium hydrogen phosphate dodecahydrate, sodium sulfate decahydrate, and sodium thiosulfate pentahydrate.

[0009] Preferably, the organic solid-liquid phase change material is one to three of the following: dodecanol, tetradecyl alcohol, hexadecyl alcohol, octadecyl alcohol, eicosyl alcohol, polyethylene glycol, neopentyl glycol, tetradecane, hexadecane, octadecane, eicosyl, paraffin, decanoic acid, lauric acid, palmitic acid, stearic acid, methyl stearate, ethyl stearate, propyl stearate, butyl stearate, methyl palmitate, ethyl palmitate, and propyl palmitate.

[0010] Preferably, the emulsifier and thickener are 1 to 3 of the following: xanthan gum, polysorbate, glyceryl ester, hydroxypropyl methylcellulose, Span 80, sodium carboxymethyl cellulose, glyceryl ester, polyacrylamide, and sodium alginate.

[0011] Preferably, the porous support material is one to three of the following: carbon foam, graphene, expanded graphite, porous carbon, diatomaceous earth, kaolin, bentonite, expanded perlite, ceramsite, montmorillonite, expanded vermiculite, and silica aerogel.

[0012] More preferably, the inorganic solid-liquid phase change material is sodium carbonate decahydrate and disodium hydrogen phosphate dodecahydrate, the organic solid-liquid phase change material is methyl palmitate, the emulsifier and thickener are sodium carboxymethyl cellulose, and the porous support material is silica aerogel.

[0013] More preferably, the organic / inorganic solid-liquid phase change material is composed of 25.6 wt% sodium carbonate decahydrate, 38.4 wt% disodium hydrogen phosphate dodecahydrate, 6.4 wt% methyl palmitate, 9.6 wt% sodium carboxymethyl cellulose, and 20 wt% silica aerogel by mass percentage.

[0014] Another object of the present invention is to provide a method for preparing the above-mentioned organic / inorganic composite phase change material suitable for building thermal management.

[0015] A method for preparing an organic / inorganic composite phase change material suitable for building thermal management includes the following process steps:

[0016] (1) An inorganic hydrated salt solution was prepared by heating the inorganic phase change material in a water bath and stirring.

[0017] (2) Dissolve and mix the organic phase change material and the above inorganic hydrated salt solution under water bath heating conditions, then add a thickener and stir to obtain an organic / inorganic composite phase change material;

[0018] (3) The organic / inorganic composite phase change material was prepared by vacuum impregnation: the organic / inorganic composite phase change material was melted; a porous support material was added to it for encapsulation, and after stirring, vacuum adsorption was performed to obtain the shaped organic / inorganic composite phase change material.

[0019] Furthermore, the specific steps are as follows:

[0020] Step 1: Preparation of inorganic eutectic materials:

[0021] First, mix 4g of sodium carbonate decahydrate and 6g of disodium hydrogen phosphate dodecahydrate in a 20mL transparent glass bottle, ensuring the total mass of the mixture is 10g. Next, dissolve the mixture in a 50℃ water bath for 90 minutes. Finally, stir the mixture with a magnetic stirrer for 30 minutes to obtain the inorganic eutectic hydrated salt.

[0022] Step 2, Preparation of organic / inorganic composite materials:

[0023] The preparation method of organic / inorganic composite phase change material is as follows: 1g of methyl palmitate and the prepared inorganic eutectic hydrated salt are dissolved and mixed evenly in a water bath at 50℃ and set aside. Then, 1.5g of sodium carboxymethyl cellulose is added to the mixture, and it is stirred evenly under magnetic stirring for 30 minutes to obtain the organic / inorganic composite phase change material.

[0024] Step 3: Preparation of shape-stabilized phase change materials:

[0025] A shaped organic / inorganic composite phase change material was prepared using a vacuum impregnation method. The preparation method is as follows: First, 12.5 g of the prepared organic / inorganic composite phase change material was placed in a 100 mL beaker and then placed in a vacuum drying oven at 50 °C to melt. Next, 3.1 g of silica aerogel was added and stirred evenly with a glass mixer, and then placed in a vacuum drying oven for vacuum adsorption for 1 hour to obtain the shaped organic / inorganic composite phase change material.

[0026] Preferably, the application range of the material is 18–32°C.

[0027] More preferably, the phase transition temperature of the material is 19.7°C.

[0028] More preferably, the phase transition enthalpy of the material is 174.1 J / g.

[0029] Another objective of this invention is to apply the aforementioned organic / inorganic composite phase change material to the field of building energy conservation. The prepared organic / inorganic composite phase change material with a high enthalpy value was filled into a constructed building model as a "thermal buffer" layer, and its "thermal buffering" effect compared to adding low thermal conductivity foam material was tested.

[0030] The beneficial effects of this invention are as follows:

[0031] This material possesses a high phase change enthalpy of 174.1 J / g and exhibits excellent flame retardant properties, without issues such as supercooling or phase separation. Furthermore, it demonstrates good shape stability and superior cycling performance. Typically, phase change materials used in building thermal management act as a "thermal buffer," delaying the rise of the building's internal temperature to high temperatures in hot weather and providing insulation in cold weather, thus maintaining the building's internal temperature within a comfortable range and saving energy for cooling or heating. Based on this, this work constructed a simple building model to test the application effect of a standardized organic / inorganic composite phase change material system. This invention fills the interlayer with foam and composite phase change material, respectively, and tests the time required for the model's internal temperature to rise from 14°C to ambient temperature and then drop back to 14°C at an ambient temperature (simulated in a constant temperature and humidity chamber) of 30°C. Finally, the material also demonstrated excellent building thermal management capabilities: compared to the foam model, the composite phase change material had a 5.8-fold longer heating time and a 3.9-fold longer cooling time; it has a good building "thermal buffering" capacity and has great potential for practical application.

[0032] This invention discloses a high-enthalpy organic / inorganic composite phase change material suitable for thermal management of building exterior insulation. Two inorganic hydrated salt phase change materials are selected: sodium carbonate decahydrate and disodium hydrogen phosphate dodecahydrate. Both of these phase change materials have the advantages of low phase change temperature and high phase change enthalpy, but their phase change temperature is still higher than the ideal building temperature requirement. Eutectic hydrated salts, on the other hand, are mixtures formed by the melting or crystallization of two or more hydrated salt phase change materials. The phase change temperature after eutecticization is lower than that of any single component, and the phase change enthalpy is also close to that of a single component. Therefore, the phase change temperature of the phase change system can be adjusted using the eutectic phenomenon to meet the requirements of building thermal management.

[0033] To determine the optimal ratio of the two inorganic eutectic hydrated salt phase change materials mentioned above, this invention prepared SCD / DHPD eutectic mixtures (1:9 to 9:1) at different mass ratios and used DSC characterization technology to test the thermal properties of the inorganic eutectic hydrated salt mixtures at different ratios. Finally, it was found that when SCD accounted for 40% of the system mass ratio, a single endothermic and exothermic peak appeared on the DSC spectrum. This indicates that a eutectic system was formed between SCD and DHPD, with a phase change temperature of 20.5℃, within the temperature range required for building thermal management. However, it still suffers from overcooling. Therefore, this invention aims to add organic phase change material MP to form an organic / inorganic composite phase change material system, which can alleviate the problems of overcooling and phase separation of the inorganic eutectic to some extent; it also solves the problem of the flammability of organic phase change material MP. However, organic phase change material cannot be uniformly mixed with inorganic phase change material into a single phase. Therefore, this invention adds CMC to solve this problem. This invention prepared organic / inorganic composite phase change materials with different CMC and MP ratios and performed DSC characterization tests to determine the optimal ratio. Because solid-liquid phase change materials generate a liquid phase during phase transition, they are highly susceptible to leakage when fully converted to a liquid state, which hinders their practical applications. Silica aerogel, a porous material with low thermal conductivity, high heat absorption capacity, and abundant nanopores, can be used as a supporting framework to encapsulate solid-liquid phase change materials, thereby preventing leakage.

[0034] Therefore, this invention uses silica aerogel to encapsulate organic / inorganic composite phase change materials to prepare shaped organic / inorganic composite phase change materials, and conducts leakage tests to characterize their shape stability. Using silica aerogel as the encapsulation material, a shaped organic / inorganic composite phase change material was successfully prepared. Attached Figure Description

[0035] Figure 1In Example 1, a is the infrared spectrum of DHPD, SCD and EHS; b is the XRD spectrum of DHPD, SCD and EHS; and c is the DSC spectrum of DHPD, SCD and EHS.

[0036] Figure 2 In Example 1, a is the infrared spectrum of MP, EHS and ME / CMC; b is the XRD spectrum of MP, EHS and ME / CMC; and c is the DSC spectrum of EHS and ME / CMC / SiO2.

[0037] Figure 3 Image a shows the change in morphology of ME with heating time in Implementation Case 1; image b shows the change in morphology of ME / CMC / SiO2 with heating time.

[0038] Figure 4 In Example 1, a is a digital photograph of ME solutions with and without CMC; b is a combustion test diagram of ME / CMC / SiO2 at different times and a comparison diagram of ME / CMC / SiO2 before and after combustion.

[0039] Figure 5 In Figure a, the cooling curve of EHS in Implementation Case 1 is shown; in Figure b, the cooling curve of ME / CMC / SiO2 in Implementation Case 1 is shown.

[0040] Figure 6 In Figure a, the infrared spectra of ME / CMC, SiO2 in Example 1 and ME / CMC / SiO2 in Example 3 are shown; in Figure b, the XRD spectra of ME / CMC, SiO2 and ME / CMC / SiO2 in Example 1 are shown.

[0041] Figure 7 In Figure a, the temperature rise and fall curves are shown for foam filling the simulated building interlayer; in Figure b, the temperature rise and fall curves are shown for shaped organic / inorganic composite phase change material filling the simulated building interlayer. Detailed Implementation

[0042] 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.

[0043] 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.

[0044] One of the specific implementation methods:

[0045] A shape-stabilized organic / inorganic composite phase change material with thermal insulation function, wherein the organic / inorganic solid-liquid phase change material is composed of the following components by mass percentage:

[0046] Inorganic solid-liquid phase change materials: 50–80 wt%;

[0047] Organic solid-liquid phase change materials: 5–30 wt%;

[0048] Thickener: 5-15 wt%;

[0049] Porous support material: 10-30 wt%.

[0050] Preferably, the high thermal conductivity flexible phase change material of this invention is composed of the following components by mass percentage:

[0051] Inorganic solid-liquid phase change material: 64 wt%;

[0052] Organic solid-liquid phase change material: 6.4 wt%;

[0053] Thickener: 9.6 wt%;

[0054] Porous support material: 20 wt%.

[0055] The inorganic phase change materials of this invention are preferably 1 to 3 of the following: sodium acetate trihydrate, barium hydroxide octahydrate, magnesium chloride hexahydrate, calcium chloride hexahydrate, magnesium sulfate heptahydrate, sodium carbonate decahydrate, disodium hydrogen phosphate dodecahydrate, sodium sulfate decahydrate, and sodium thiosulfate pentahydrate.

[0056] The preferred organic phase change materials in all organic / inorganic solid-liquid phase change materials of this invention are 1 to 3 of the following: dodecanol, tetradecyl alcohol, hexadecyl alcohol, octadecyl alcohol, eicosyl alcohol, polyethylene glycol, neopentyl glycol, tetradecane, hexadecane, octadecane, eicosyl, paraffin, decanoic acid, lauric acid, palmitic acid, stearic acid, methyl stearate, ethyl stearate, propyl stearate, butyl stearate, methyl palmitate, ethyl palmitate, and propyl palmitate.

[0057] In this invention, the emulsifier and thickener of all inorganic / inorganic solid-liquid phase change materials are preferably 1 to 3 of the following: xanthan gum, polysorbate, glyceryl ester, hydroxypropyl methylcellulose, Span 80, sodium carboxymethyl cellulose, glyceryl ester, polyacrylamide, and sodium alginate.

[0058] The preferred porous support material for all inorganic / inorganic solid-liquid phase change materials of this invention is one to three of the following: carbon foam, graphene, expanded graphite, porous carbon, diatomaceous earth, kaolin, bentonite, expanded perlite, ceramsite, montmorillonite, expanded vermiculite, and silica aerogel.

[0059] A method for preparing a high-enthalpy organic / inorganic composite phase change material includes the following steps: First, the inorganic phase change material is placed in a 20mL transparent glass bottle, then dissolved in a 50℃ water bath for 90 minutes, and finally stirred under magnetic stirring for 30 minutes to obtain an inorganic hydrated salt solution. The organic phase change material and the prepared inorganic hydrated salt solution are dissolved and mixed evenly in a 50℃ water bath, then an emulsifier and thickener are added, and the mixture is stirred under magnetic stirring for 30 minutes to obtain the organic / inorganic composite phase change material. A vacuum impregnation method is used to prepare a shaped organic / inorganic composite phase change material. The preparation method is as follows: First, the prepared organic / inorganic composite phase change material is placed in a 100mL beaker, then melted in a 50℃ vacuum drying oven. Secondly, a porous support material is added for encapsulation. After being stirred evenly with glass, the material is placed in a vacuum drying oven for vacuum adsorption for 1 hour to obtain a shaped organic / inorganic composite phase change material.

[0060] A high-enthalpy organic / inorganic composite phase change material suitable for building thermal management can be filled into building interlayers to effectively reduce building energy consumption and achieve energy conservation.

[0061] Example 1

[0062] (1) First, mix 6g DHPD and 4g SCD and place them in a 20mL transparent glass bottle. Dissolve the mixture in a 50℃ water bath for 90 minutes and set aside. Then, stir the mixture under magnetic stirring for 30 minutes to obtain inorganic eutectic hydrated salt (EHS). Compared with single inorganic hydrated salt phase change materials, the enthalpy of eutectic hydrated salt phase change materials remains basically unchanged, but the phase change temperature decreases to 20.5℃, making it more suitable for some low-temperature environmental protection and energy-saving fields, such as buildings.

[0063] (2) Dissolve and mix 1g of methyl palmitate (MP) and the prepared inorganic eutectic hydrated salt in a water bath at 50°C until homogeneous and set aside. Then add 1.5g of sodium carboxymethyl cellulose (CMC) and stir it under magnetic stirring for 30 minutes to obtain the organic / inorganic composite phase change material.

[0064] (3) A shaped organic / inorganic composite phase change material (ME / CMC / SiO2) was prepared using a vacuum impregnation method. The preparation method is as follows: First, 12.5g of the prepared organic / inorganic composite phase change material was placed in a 100mL beaker and then placed in a vacuum drying oven at 50℃ to melt. Next, 3.1g of silica aerogel was added, and after stirring evenly with a glass, the mixture was placed in a vacuum drying oven for vacuum adsorption for 1 hour to obtain the shaped organic / inorganic composite phase change material. The phase transition temperature of this shaped organic / inorganic composite phase change material is 19.7℃, which is within the applicable temperature range for building energy conservation.

[0065] (4) A self-built architectural model was used to conduct building thermal management tests on the CPCM. The architectural model consisted of a 100*100*60mm hexahedron as the outer model and an 80*80*58mm smaller hexahedron as the inner model nested together. The thickness of the interlayer between the two models was 10mm. Foam and the shaped composite phase change material prepared in step three were added to the interlayer to test their respective thermal management performance. The specific test procedure was as follows: First, the architectural model was placed in a constant temperature and humidity chamber (YH-H, Hangzhou Wujia Machinery Co., Ltd., China) at different temperatures (25℃, 30℃, and 35℃). A temperature recorder (MIK-R5000C, Hangzhou Meikong Automation Technology Co., Ltd., China) was used to record the temperature change at the center of the model. Then, the time required for the center of the model to rise to the set temperature was tested; then, it was cooled to room temperature, and the time required for the center of the model to drop from the set temperature to room temperature was tested to determine the building thermal management performance of the material.

[0066] Example 2

[0067] Disodium hydrogen phosphate dodecahydrate: 1g; sodium carbonate decahydrate: 9g; methyl palmitate: 1g; emulsifier and thickener: 1.5g; silica aerogel: 3.1g. Other conditions were the same as in Example 1.

[0068] Example 3

[0069] Disodium hydrogen phosphate dodecahydrate: 2g; sodium carbonate decahydrate: 8g; methyl palmitate: 1g; emulsifier and thickener: 1.5g; silica aerogel: 3.1g. Other conditions were the same as in Example 1.

[0070] Example 4

[0071] Disodium hydrogen phosphate dodecahydrate: 3g; sodium carbonate decahydrate: 7g; methyl palmitate: 1g; emulsifier and thickener: 1.5g; silica aerogel: 3.1g. Other conditions were the same as in Example 1.

[0072] Example 5

[0073] Disodium hydrogen phosphate dodecahydrate: 4g; sodium carbonate decahydrate: 6g; methyl palmitate: 1g; emulsifier and thickener: 1.5g; silica aerogel: 3.1g. Other conditions were the same as in Example 1.

[0074] Example 6

[0075] Disodium hydrogen phosphate dodecahydrate: 5g; sodium carbonate decahydrate: 5g; methyl palmitate: 1g; emulsifier and thickener: 1.5g; silica aerogel: 3.1g. Other conditions were the same as in Example 1.

[0076] Example 7

[0077] Disodium hydrogen phosphate dodecahydrate: 7g; sodium carbonate decahydrate: 3g; methyl palmitate: 1g; emulsifier and thickener: 1.5g; silica aerogel: 3.1g. Other conditions were the same as in Example 1.

[0078] Example 8

[0079] Disodium hydrogen phosphate dodecahydrate: 8g; sodium carbonate decahydrate: 2g; methyl palmitate: 1g; emulsifier and thickener: 1.5g; silica aerogel: 3.1g. Other conditions were the same as in Example 1.

[0080] Example 9

[0081] Disodium hydrogen phosphate dodecahydrate: 9g; sodium carbonate decahydrate: 1g; methyl palmitate: 1g; emulsifier and thickener: 1.5g; silica aerogel: 3.1g. Other conditions were the same as in Example 1.

[0082] Example 10

[0083] Disodium hydrogen phosphate dodecahydrate: 6g; sodium carbonate decahydrate: 4g; methyl palmitate: 1g; emulsifier and thickener: 1.5g; silica aerogel: 1.9g. Other conditions were the same as in Example 1.

[0084] Example 11

[0085] Disodium hydrogen phosphate dodecahydrate: 6g; sodium carbonate decahydrate: 4g; methyl palmitate: 1g; emulsifier and thickener: 1.5g; silica aerogel: 2.2g. Other conditions were the same as in Example 1.

[0086] Example 12

[0087] Disodium hydrogen phosphate dodecahydrate: 6g; sodium carbonate decahydrate: 4g; methyl palmitate: 1g; emulsifier and thickener: 1.5g; silica aerogel: 4.2g. Other conditions were the same as in Example 1.

[0088] Example 13

[0089] Disodium hydrogen phosphate dodecahydrate: 6g; sodium carbonate decahydrate: 4g; methyl palmitate: 1g; emulsifier and thickener: 1.5g; silica aerogel: 5.4g. Other conditions were the same as in Example 1.

[0090] From the infrared spectrum of the material ( Figure 1 As can be seen in a), all the diffraction peaks of SCD and DHPD appeared in the infrared spectrum of EHS, and no new diffraction peaks appeared. This indicates that SCD and DHPD are only combined through physical interaction and no chemical reaction has occurred.

[0091] XRD characterization of inorganic hydrated salt materials Figure 1 As can be seen in b), in addition to retaining all the characteristic diffraction peaks of SCD and DHPD, the diffraction peaks of the obtained EHS also show many new characteristic peaks, which indicates that the crystal form of EHS has changed and proves that it has formed a eutectic structure.

[0092] DSC characterization of inorganic hydrated salt materials ( Figure 1 As shown in c), when SCD accounts for 40% of the system mass, the DSC spectrum exhibits a single endothermic and exothermic peak. This indicates that a eutectic system is formed between SCD and DHPD, with a phase transition temperature of 20.5℃, which is within the temperature range required for building thermal management.

[0093] From the infrared spectrum of the material ( Figure 2 As can be seen in a), compared with the infrared spectra of the other two (inorganic eutectic EHS and methyl palmitate MP), the infrared spectra of the high enthalpy organic / inorganic composite phase change material (ME / CMC) contain all the diffraction peaks of EHS and MP, and no new diffraction peaks appear. This indicates that the organic / inorganic composite phase change materials are only connected by physical interaction and no chemical reaction occurs.

[0094] XRD characterization of materials Figure 2 As can be seen in b), compared with the infrared spectra of the other two (inorganic eutectic EHS and methyl palmitate MP), the infrared spectrum of the high enthalpy organic / inorganic composite phase change material (ME / CMC) did not show any new characteristic diffraction peaks. This indicates that the two are only physically bonded and no chemical reaction occurs.

[0095] The DSC curve of the crystallization peak of the obtained high-enthalpy organic-inorganic composite phase change energy storage material was obtained. Figure 2As shown in c), the enthalpy of the high-enthalpy organic / inorganic composite phase change material (ME / CMC / SiO2) is lower than that of the other two (inorganic eutectic EHS and methyl palmitate MP). This is because the physically added CMC and silica aerogel do not possess phase change properties. However, the phase change enthalpy of ME / CMC / SiO2 reaches 174.1 J / g, exhibiting good phase change thermal storage characteristics.

[0096] Figure 3 In the figure, (a) represents ME and (b) represents the change of ME / CMC / SiO2 with heating time. When the temperature is heated to 65℃ and the heating time is 15min, ME has begun to melt. However, the obtained ME / CMC / SiO2 high enthalpy organic-inorganic composite phase change energy storage material remains solid and does not flow even when heated for 60min, indicating that the material has excellent shape-stabilized phase change characteristics.

[0097] Figure 4 As can be seen from Figure a, organic / inorganic composite phase change materials have the problem that the organic phase is difficult to mix with the inorganic phase to form a uniform phase, and ME exhibits obvious stratification. However, after adding CMC, ME / CMC becomes a uniform phase, solving the problem that organic-inorganic phase change materials are difficult to mix into a single phase.

[0098] While organic phase change materials (PCMs) do not suffer from supercooling or phase separation issues, they are inherently flammable. Adding inorganic PCMs to form organic / inorganic composite PCM systems can significantly reduce their flammability. Figure 4 As can be seen from Figure b, ME / CMC / SiO2 still cannot be burned after being burned by an alcohol lamp for one minute, and no dripping of molten material was observed after burning, proving that ME / CMC / SiO2 has good flame retardant properties.

[0099] Figure 5 In Figure 'a', the cooling curve of the SCD is shown, with a subcooling degree of 4.7℃. Figure 5 Figure b shows the cooling curve of DHPD, with a supercooling degree as high as 9.2℃. Figure 5 c represents the cooling curve of EHS, with an undercooling of 6.6℃. When we add organic phase change materials to the inorganic eutectic system and then encapsulate it with silica aerogel, we find that the encapsulated, shaped organic / inorganic composite phase change material ME / CMC / SiO2 no longer exhibits undercooling. Figure 5 (d) This indicates that forming a shaped organic / inorganic composite phase change system can effectively eliminate the problem of high undercooling in inorganic phase change materials.

[0100] From the infrared spectrum of the material ( Figure 6As can be seen in a), compared with the infrared spectra of the other two (organic / inorganic composite phase change materials ME / CMC and silica aerogel SiO2), the infrared spectrum of the shaped high enthalpy organic / inorganic composite phase change material (ME / CMC / SiO2) contains all the diffraction peaks of ME / CMC and SiO2, and no new diffraction peaks appear. This indicates that the shaped organic / inorganic composite phase change materials are only connected by physical interaction and no chemical reaction occurs.

[0101] XRD characterization of materials Figure 6 As can be seen in b), compared with the infrared spectra of the other two (organic / inorganic composite phase change materials ME / CMC and silica aerogel SiO2), the infrared spectrum of the high enthalpy organic / inorganic composite phase change material (ME / CMC / SiO2) did not show any new characteristic diffraction peaks. This indicates that the two are only physically bonded and no chemical reaction occurs.

[0102] Generally, phase change materials (PCCs) used in building thermal management act as a "thermal buffer," slowing the rise of the building's interior temperature to high temperatures in hot weather and insulating the interior in cold weather, thus maintaining the building's interior temperature within a comfortable range and saving energy consumption for cooling or heating. Based on this, this work constructed a simple building model to test the application effect of a standardized organic / inorganic composite PCC system. Figure 7 We tested the time required for the internal temperature of the model to rise from 14°C to ambient temperature and then fall back to 14°C at an ambient temperature (simulated in a constant temperature and humidity chamber) of 30°C by filling the interlayer with foam and CPCM respectively. Figure 7 As shown in Figure a, the heating time for the foam-filled model was 24.1 min, and the cooling time was 46.2 min; while the heating time for the CPCM-filled model was 140.0 min, and the cooling time was 180.5 min. Compared to the foam-filled building model, the heating time was extended by 5.8 times, and the cooling time by 3.9 times. In summary, CPCM can significantly improve the heating and cooling time inside buildings, exhibiting excellent building "thermal buffering" capabilities and possessing significant practical application value. Other methods for preparing this phase change material include:

[0103] Examples 14-26

[0104] By using sodium acetate trihydrate instead of one of sodium carbonate decahydrate or disodium hydrogen phosphate dodecahydrate as a phase change material, a corresponding high enthalpy organic / inorganic composite phase change material was obtained, with other conditions consistent with Examples 1-13.

[0105] Examples 27-39

[0106] By using barium hydroxide octahydrate instead of one of sodium carbonate decahydrate or disodium hydrogen phosphate dodecahydrate as the phase change material, a corresponding high enthalpy organic / inorganic composite phase change material was obtained, with other conditions consistent with Examples 1-13.

[0107] Examples 40-52

[0108] Magnesium chloride hexahydrate was used instead of one of sodium carbonate decahydrate or disodium hydrogen phosphate dodecahydrate as a phase change material to obtain a corresponding high enthalpy organic / inorganic composite phase change material, with other conditions consistent with Examples 1-13.

[0109] Examples 53-65

[0110] By using calcium chloride hexahydrate instead of one of sodium carbonate decahydrate or disodium hydrogen phosphate dodecahydrate as a phase change material, a corresponding high enthalpy organic / inorganic composite phase change material was obtained, with other conditions consistent with Examples 1-13.

[0111] Examples 66-78

[0112] Magnesium sulfate heptahydrate was used instead of one of sodium carbonate decahydrate or disodium hydrogen phosphate dodecahydrate as a phase change material to obtain a corresponding high enthalpy organic / inorganic composite phase change material, with other conditions consistent with Examples 1-13.

[0113] Examples 79-91

[0114] By using sodium sulfate decahydrate instead of either sodium carbonate decahydrate or disodium hydrogen phosphate dodecahydrate as the phase change material, a corresponding high enthalpy organic / inorganic composite phase change material was obtained, with other conditions consistent with Examples 1-13.

[0115] Examples 92-104

[0116] By using sodium thiosulfate pentahydrate instead of one of sodium carbonate decahydrate or disodium hydrogen phosphate dodecahydrate as a phase change material, a corresponding high enthalpy organic / inorganic composite phase change material was obtained, with other conditions consistent with Examples 1-13.

[0117] Examples 105-117

[0118] By using dodecyl alcohol instead of methyl palmitate as the phase change material, a corresponding high enthalpy organic / inorganic composite phase change material was obtained, with other conditions consistent with Examples 1-13.

[0119] Examples 118-130

[0120] By using tetradecyl alcohol instead of methyl palmitate as the phase change material, a corresponding high enthalpy organic / inorganic composite phase change material was obtained, with other conditions consistent with Examples 1-13.

[0121] Examples 131-143

[0122] By using hexadecyl alcohol instead of methyl palmitate as the phase change material, a corresponding high enthalpy organic / inorganic composite phase change material was obtained, with other conditions consistent with those in Examples 1-13.

[0123] Examples 144-156

[0124] By using octadecyl alcohol instead of methyl palmitate as the phase change material, a corresponding high enthalpy organic / inorganic composite phase change material was obtained, with other conditions consistent with those in Examples 1-13.

[0125] Examples 157-169

[0126] By using eicosyl alcohol instead of methyl palmitate as the phase change material, a corresponding high enthalpy organic / inorganic composite phase change material was obtained, with other conditions consistent with Examples 1-13.

[0127] Examples 170-182

[0128] By using polyethylene glycol instead of methyl palmitate as the phase change material, a corresponding high enthalpy organic / inorganic composite phase change material was obtained, with other conditions consistent with Examples 1-13.

[0129] Examples 183-195

[0130] By using neopentyl glycol instead of methyl palmitate as the phase change material, a corresponding high enthalpy organic / inorganic composite phase change material was obtained, with other conditions consistent with those in Examples 1-13.

[0131] Examples 196-208

[0132] By using tetradecane instead of methyl palmitate as the phase change material, a corresponding high enthalpy organic / inorganic composite phase change material was obtained, with other conditions consistent with those in Examples 1-13.

[0133] Examples 209-221

[0134] By using hexadecane instead of methyl palmitate as the phase change material, a corresponding high enthalpy organic / inorganic composite phase change material was obtained, with other conditions consistent with those in Examples 1-13.

[0135] Examples 222-234

[0136] By using octadecane instead of methyl palmitate as the phase change material, a corresponding high enthalpy organic / inorganic composite phase change material was obtained, with other conditions consistent with those in Examples 1-13.

[0137] Examples 235-247

[0138] By using eicosane instead of methyl palmitate as the phase change material, a corresponding high enthalpy organic / inorganic composite phase change material was obtained, with other conditions consistent with Examples 1-13.

[0139] Examples 248-260

[0140] By using paraffin instead of methyl palmitate as the phase change material, a corresponding high enthalpy organic / inorganic composite phase change material was obtained, with other conditions consistent with Examples 1-13.

[0141] Examples 261-273

[0142] By using decanoic acid instead of methyl palmitate as the phase change material, a corresponding high enthalpy organic / inorganic composite phase change material was obtained, with other conditions consistent with those in Examples 1-13.

[0143] Examples 274-286

[0144] Lauric acid was used instead of methyl palmitate as the phase change material to obtain a corresponding high enthalpy organic / inorganic composite phase change material, with other conditions consistent with those in Examples 1-13.

[0145] Examples 287-299

[0146] By using palmitic acid instead of methyl palmitate as the phase change material, a corresponding high enthalpy organic / inorganic composite phase change material was obtained, with other conditions consistent with those in Examples 1-13.

[0147] Examples 300-312

[0148] By using stearic acid instead of methyl palmitate as the phase change material, a corresponding high enthalpy organic / inorganic composite phase change material was obtained, with other conditions consistent with those in Examples 1-13.

[0149] Examples 313-325

[0150] By using methyl stearate instead of methyl palmitate as the phase change material, a corresponding high enthalpy organic / inorganic composite phase change material was obtained, with other conditions consistent with those in Examples 1-13.

[0151] Examples 326-338

[0152] By using ethyl stearate instead of methyl palmitate as the phase change material, a corresponding high enthalpy organic / inorganic composite phase change material was obtained, with other conditions consistent with those in Examples 1-13.

[0153] Examples 339-351

[0154] By using propyl stearate instead of methyl palmitate as the phase change material, a corresponding high enthalpy organic / inorganic composite phase change material was obtained, with other conditions consistent with those in Examples 1-13.

[0155] Examples 352-364

[0156] By using butyl stearate instead of methyl palmitate as the phase change material, a corresponding high enthalpy organic / inorganic composite phase change material was obtained, with other conditions consistent with those in Examples 1-13.

[0157] Examples 365-377

[0158] Ethyl palmitate was used instead of methyl palmitate as the phase change material to obtain a corresponding high enthalpy organic / inorganic composite phase change material, with other conditions consistent with those in Examples 1-13.

[0159] Examples 378-390

[0160] By using propyl palmitate instead of methyl palmitate as the phase change material, a corresponding high enthalpy organic / inorganic composite phase change material was obtained, with other conditions consistent with Examples 1-13.

[0161] Examples 391-403

[0162] By using xanthan gum instead of sodium carboxymethyl cellulose as an emulsifier and thickener, a corresponding high enthalpy organic / inorganic composite phase change material was obtained, with other conditions consistent with those in Examples 1-13.

[0163] Examples 404-416

[0164] By using polysorbate instead of sodium carboxymethyl cellulose as an emulsifier and thickener, a corresponding high enthalpy organic / inorganic composite phase change material was obtained, with other conditions consistent with those in Examples 1-13.

[0165] Examples 417-429

[0166] By using glyceryl esters instead of sodium carboxymethyl cellulose as emulsifiers and thickeners, corresponding high enthalpy organic / inorganic composite phase change materials were obtained, with other conditions consistent with Examples 1-13.

[0167] Examples 430-442

[0168] Hydroxypropyl methylcellulose was used instead of sodium carboxymethyl cellulose as an emulsifier and thickener to obtain a corresponding high enthalpy organic / inorganic composite phase change material, with other conditions consistent with those in Examples 1-13.

[0169] Examples 443-455

[0170] By using Span 80 instead of sodium carboxymethyl cellulose as an emulsifier and thickener, a corresponding high enthalpy organic / inorganic composite phase change material was obtained, with other conditions consistent with those in Examples 1-13.

[0171] Examples 456-468

[0172] By using glyceryl esters instead of sodium carboxymethyl cellulose as emulsifiers and thickeners, corresponding high enthalpy organic / inorganic composite phase change materials were obtained, with other conditions consistent with Examples 1-13.

[0173] Examples 469-481

[0174] By using polyacrylamide instead of sodium carboxymethyl cellulose as an emulsifier and thickener, a corresponding high enthalpy organic / inorganic composite phase change material was obtained, with other conditions consistent with those in Examples 1-13.

[0175] Examples 482-494

[0176] Sodium alginate was used instead of sodium carboxymethyl cellulose as an emulsifier and thickener to obtain a corresponding high enthalpy organic / inorganic composite phase change material, with other conditions consistent with those in Examples 1-13.

[0177] Examples 495-507

[0178] By using carbon foam instead of silica aerogel as a porous support material, a corresponding high enthalpy organic / inorganic composite phase change material was obtained, with other conditions consistent with Examples 1-13.

[0179] Examples 508-520

[0180] By using graphene instead of silica aerogel as a porous support material, a corresponding high enthalpy organic / inorganic composite phase change material was obtained, with other conditions consistent with those in Examples 1-13.

[0181] Examples 521-533

[0182] Expanded graphite was used instead of silica aerogel as a porous support material to obtain a corresponding high enthalpy organic / inorganic composite phase change material, with other conditions consistent with those in Examples 1-13.

[0183] Examples 534-546

[0184] By using porous carbon instead of silica aerogel as a porous support material, a corresponding high enthalpy organic / inorganic composite phase change material was obtained, with other conditions consistent with those in Examples 1-13.

[0185] Examples 547-559

[0186] Diatomaceous earth was used instead of silica aerogel as a porous support material to obtain a corresponding high enthalpy organic / inorganic composite phase change material, with other conditions consistent with those in Examples 1-13.

[0187] Examples 560-572

[0188] By using kaolin instead of silica aerogel as a porous support material, a corresponding high enthalpy organic / inorganic composite phase change material was obtained, with other conditions consistent with those in Examples 1-13.

[0189] Examples 573-585

[0190] By using bentonite instead of silica aerogel as a porous support material, a corresponding high enthalpy organic / inorganic composite phase change material was obtained, with other conditions consistent with those in Examples 1-13.

[0191] Examples 586-598

[0192] Expanded perlite was used instead of silica aerogel as a porous support material to obtain a corresponding high enthalpy organic / inorganic composite phase change material, with other conditions consistent with those in Examples 1-13.

[0193] Examples 599-611

[0194] By using ceramsite instead of silica aerogel as a porous support material, a corresponding high enthalpy organic / inorganic composite phase change material was obtained, with other conditions consistent with those in Examples 1-13.

[0195] Examples 612-624

[0196] Montmorillonite was used instead of silica aerogel as a porous support material to obtain a corresponding high enthalpy organic / inorganic composite phase change material, with other conditions consistent with those in Examples 1-13.

[0197] Examples 625-637

[0198] Expanded vermiculite was used instead of silica aerogel as a porous support material to obtain a corresponding high enthalpy organic / inorganic composite phase change material, with other conditions consistent with those in Examples 1-13.

[0199] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A shaped organic / inorganic composite phase change material, characterized in that: Includes inorganic solid-liquid phase change materials, organic solid-liquid phase change materials, thickeners, and porous support materials; by mass percentage: 50-80 wt% inorganic solid-liquid phase change material; the inorganic solid-liquid phase change material is a eutectic hydrated salt of sodium carbonate decahydrate and disodium hydrogen phosphate dodecahydrate; 5-30 wt% organic solid-liquid phase change material; wherein the organic solid-liquid phase change material is methyl palmitate; Thickener 5~15wt%; Porous support material 10~30wt%.

2. The shaped organic / inorganic composite phase change material according to claim 1, characterized in that: The thickener is one to three of the following: xanthan gum, polysorbate, glyceryl ester, hydroxypropyl methylcellulose, Span 80, sodium carboxymethyl cellulose, carboxymethyl starch, glyceryl ester, polyacrylamide, and sodium alginate.

3. The shaped organic / inorganic composite phase change material according to claim 1, characterized in that, The porous support material is carbon foam, graphene, expanded graphite, porous carbon, diatomaceous earth, kaolin, bentonite, expanded perlite, ceramsite, montmorillonite, expanded vermiculite, or silica aerogel.

4. A method for preparing an organic / inorganic composite phase change material according to any one of claims 1-3, characterized in that, Includes the following steps: (1) An inorganic hydrated salt solution was prepared by heating the inorganic phase change material in a water bath and stirring. (2) Dissolve and mix the organic phase change material and the above inorganic hydrated salt solution under water bath heating conditions, then add a thickener and stir to obtain an organic / inorganic composite phase change material; (3) Preparation of shaped organic / inorganic composite phase change material by vacuum impregnation method: The above organic / inorganic composite phase change material is melted; porous support material is added to it for encapsulation, and after stirring, vacuum adsorption is performed to obtain shaped organic / inorganic composite phase change material.

5. The application of the organic / inorganic composite phase change material according to any one of claims 1-3, characterized in that: The composite phase change material is used in building insulation and thermal management.

6. The application of the organic / inorganic composite phase change material according to claim 5, characterized in that: The composite phase change material is used in a temperature range of 18~32℃.

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