Medium temperature zone phase change material and preparation method thereof
By reacting stearic acid with zinc salt under the action of triethylamine and ethanol, a new medium-temperature phase change material was prepared, which solved the problems of complex synthesis of existing materials and poor phase change performance, and achieved a medium-temperature phase change material with high enthalpy, low supercooling and good stability.
Patent Information
- Application Number
- CN202311706251.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-11
- Publication Date
- 2025-06-13
AI Technical Summary
The current phase change material synthesis process in the medium temperature zone is complex, the phase change enthalpy value is low, and the supercooling degree is large, which cannot meet the temperature control needs of the medium temperature zone.
A new medium-temperature phase change material was prepared by stirring, reacting, centrifuging and drying a mixed solution of stearic acid, zinc salt, triethylamine and ethanol. This method is simple, and the resulting phase change material has high phase change enthalpy and low supercooling degree.
The efficient preparation of phase change materials in the medium temperature zone is achieved, with the phase change enthalpy value between 120J/g and 190J/g, the supercooling degree between 3 and 15°C, and the phase change cycle stability is good, and it is suitable for thermal energy collection and temperature control in the medium temperature zone.
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Figure HDA0004606452250000011
Abstract
Description
Technical Field
[0001] The present application relates to a phase change material in the medium temperature range and a preparation method thereof, belonging to the field of preparation methods of phase change materials. Background Art
[0002] Energy and environment are the two major themes currently faced by mankind. Heat energy collection and storage are important ways of energy conversion and utilization. Phase change materials can absorb or release a large amount of latent heat when the substance undergoes a phase change and keep the system temperature constant, which can realize environmental temperature control or heat energy storage. It has wide applications in heat energy collection, building temperature control, and industrial waste heat recovery. Compared with other phase change materials, organic phase change materials have large latent heat and stable phase change performance, and have received wide attention.
[0003] The heat collection and utilization in the medium temperature range (100 - 200 °C) have important application prospects in industrial and household fields. For example: heating water and space, steam generation, sterilization or other industrial processes, etc. However, the commonly used organic phase change materials have low phase change temperatures, and there are few phase change materials available in the medium temperature range, which cannot meet the temperature control requirements in the medium temperature range. Therefore, the development and application of new medium temperature range phase change materials have important research and application significance. Summary of the Invention
[0004] In view of the disadvantages of the existing synthesis process of medium temperature range phase change materials, such as complex synthesis process, low phase change enthalpy value, and large supercooling degree, which cannot meet the application requirements. Therefore, developing and synthesizing a new medium temperature range phase change material with a simple synthesis method, high enthalpy value, and low supercooling degree has important research and application value.
[0005] One aspect of the present application provides a preparation method of a phase change material in the medium temperature range, and the preparation method includes:
[0006] Stirring, reacting, centrifuging, and drying a mixed solution containing stearic acid, zinc salt, triethylamine, and ethanol to obtain the phase change material in the medium temperature range.
[0007] As a specific implementation manner, a preparation method of a new medium temperature range phase change material includes the following steps:
[0008] (1) First, mix a certain proportion of stearic acid, zinc chloride solution, and triethylamine, then add an ethanol solution and mix, and mechanically stir for sufficient reaction.
[0009] (2) Wash the reaction product with water and dichloromethane to wash away the unreacted substances, centrifuge to obtain the product, and dry the obtained product.
[0010] In the above technical solution, stearic acid reacts with zinc chloride under the action of triethylamine to form a stearic acid complex. Wash away the unreacted zinc chloride with water, wash away the unreacted stearic acid with dichloromethane, and then remove water and dichloromethane by drying.
[0011] Optionally, in the step (2), wash with water 1 - 5 times and wash with dichloromethane 1 - 5 times.
[0012] Optionally, the molar ratio of the stearic acid to the zinc salt is 1:(3 - 8).
[0013] Optionally, the molar ratio of the stearic acid to the zinc salt independently selects any value from 1:3, 1:4, 1:5, 1:6, 1:7, 1:8 or the range value between any two of the above.
[0014] Optionally, the molar ratio of the stearic acid to the triethylamine is 1:(0.5 - 3).
[0015] Optionally, the molar ratio of the stearic acid to the triethylamine independently selects any value from 1:0.5, 1:1, 1:2, 1:3 or the range value between any two of the above.
[0016] Optionally, the molar volume ratio of the stearic acid to the ethanol is 1:(10 - 50).
[0017] Optionally, the molar volume ratio of the stearic acid to the ethanol independently selects any value from 1:10, 1:20, 1:30, 1:40, 1:50 or the range value between any two of the above.
[0018] Optionally, the rotation speed of the stirring is 10 - 500 rpm;
[0019] The stirring time is 1 h - 15 h.
[0020] Optionally, the reaction temperature is 10 - 90 °C.
[0021] Optionally, the rotation speed of the centrifugation is 2000 - 9000 rpm;
[0022] The centrifugation time is 5 - 30 min.
[0023] Optionally, the drying temperature is 60 - 150 °C;
[0024] The drying time is 1 - 20 h.
[0025] In another aspect of the present application, there is provided a medium - temperature phase - change material obtained by the above - mentioned preparation method, and the phase - change enthalpy value of the medium - temperature phase - change material is 120 J / g - 190 J / g;
[0026] The supercooling degree of the medium - temperature phase - change material is 3 - 15 °C.
[0027] Optionally, the phase - change enthalpy value of the medium - temperature phase - change material is 184.16 J / g;
[0028] The supercooling degree of the phase change material in the medium temperature range is 8°C.
[0029] The beneficial effects that this application can produce include:
[0030] (1) Develop a new synthesis method for phase change materials;
[0031] (2) The synthesis method is simple, has a high enthalpy value, a low supercooling degree, and stable thermodynamic properties.
[0032] (3) In this application, a new type of phase change material in the medium temperature range is generated by the reaction of stearic acid and zinc salt. The phase change temperature is 117.49°C, and the phase change enthalpy value is 184.16 J / g. The synthesis process of the phase change material is simple, the phase change enthalpy value is relatively high, and the phase change cycle stability is good. It has important application prospects in two aspects: thermal energy collection and temperature control in the medium temperature range. Description of the Drawings
[0033] Figure 1 It is the DSC diagram of the phase change material in the medium temperature range in the embodiment of this application. Detailed Embodiments
[0034] The following details this application in combination with embodiments, but this application is not limited to these embodiments.
[0035] Unless otherwise specified, the raw materials and reagents in the embodiments of this application are all purchased through commercial channels.
[0036] The phase change material in the medium temperature range has important application prospects. However, the existing phase change materials in the medium temperature range have a low enthalpy value, poor phase change stability, and a large supercooling degree, and cannot meet the requirements of stable temperature control in the medium temperature range.
[0037] A new type of phase change material in the medium temperature range described in this application, with a simple synthesis method, a high enthalpy value, and a low supercooling degree, has important research and application values.
[0038] Embodiment 1
[0039] (1) Accurately weigh 2.8448 g of stearic acid, dissolve it in 10 ml of ethanol, and stir to mix evenly; accurately weigh 6.81575 g of zinc chloride, dissolve it in 15 ml of ethanol, and stir to mix evenly; mix the stearic acid-ethanol solution and the zinc chloride ethanol solution and stir evenly. Add 1 ml of triethylamine to the mixed solution, mechanically stir and react for 15 h, the stirring speed is 50 rpm, and react at 80°C;
[0040] (2) Wash the reactant with water and then centrifuge to obtain a precipitate, and repeat the water washing three times;
[0041] (3) After washing the product with water, continue to wash it with dichloromethane, and centrifuge at 8000 rpm for 10 min to obtain a precipitate, and repeat the washing three times;
[0042] (4) Put the washed product into an oven and dry it under vacuum at 80 °C for 10 h.
[0043] Test Example 1
[0044] In order to test the phase change thermophysical properties of the medium-temperature phase change material obtained in Example 1, differential scanning calorimetry test analysis was carried out. The test conditions were as follows: heating and cooling rate: 10 °C / min, temperature test range: 0 - 140 °C. The results are as Figure 1 shown. The melting onset temperature of the phase change material prepared in Example 1 was 117.49 °C, the melting peak temperature was 123.20 °C, and the melting peak enthalpy value was 184.16 J / g; the crystallization onset temperature was 108.18 °C, the crystallization peak temperature was 107.22 °C, and the crystallization peak enthalpy value was 184.98 J / g.
[0045] As described above, only several embodiments of the present application are provided, and it does not impose any form of limitation on the present application. Although the present application is disclosed with preferred embodiments as above, it is not intended to limit the present application. Any person skilled in the art, without departing from the scope of the technical solution of the present application, makes some changes or modifications using the technical content disclosed above, which are equivalent to equivalent implementation cases and all fall within the scope of the technical solution.
Claims
1. A preparation method of a phase change material in the medium temperature range, characterized in that, the preparation method includes: Stirring, reacting, centrifuging, and drying a mixed solution containing stearic acid, zinc chloride, triethylamine, and ethanol to obtain the phase change material in the medium temperature range.
2. The preparation method according to claim 1, characterized in that, the molar ratio of stearic acid to zinc chloride is 1:(3 - 8).
3. The preparation method according to claim 1, characterized in that, the molar ratio of stearic acid to triethylamine is 1:(0.5 - 3).
4. The preparation method according to claim 1, characterized in that, the molar volume ratio of stearic acid to ethanol is 1:(10 - 50).
5. The preparation method according to claim 1, characterized in that, the rotation speed of the stirring is 10 - 500 rpm; the stirring time is 1 h - 15 h.
6. The preparation method according to claim 1, characterized in that, the reaction temperature is 10°C - 90°C.
7. The preparation method according to claim 1, characterized in that, the rotation speed of the centrifuging is 2000 - 9000 rpm; the centrifuging time is 5 - 30 min.
8. The preparation method according to claim 1, characterized in that, the drying temperature is 60 - 150°C; the drying time is 1 - 20 h.
9. A phase change material in the medium temperature range obtained by the preparation method according to any one of claims 1 - 8, characterized in that, the phase change enthalpy value of the phase change material in the medium temperature range is 120 J / g - 190 J / g; the supercooling degree of the phase change material in the medium temperature range is 3 - 15°C.