Flexible phase change energy storage paste material, preparation method and application thereof

Abstract

The application provides a flexible phase change energy storage soft paste material and a preparation method and application thereof, relates to the technical field of phase change energy storage materials, and the flexible phase change energy storage soft paste material comprises twelve sodium hydrogen phosphate, water, a crystal structure stabilizer, a phase change form changing agent, and a phase change temperature regulator; the crystal structure stabilizer comprises at least one of glycerol, sorbitol, propylene glycol and water-soluble silicone oil; and the phase change form changing agent comprises at least one of sodium alginate, gelatin, xanthan gum, water glass, sodium dodecyl sulfonate, calcium chloride and sodium bicarbonate. The application solves the technical problems that the phase change temperature of twelve sodium hydrogen phosphate does not match the human body heat management temperature, the surface of the phase change material liquid-solid phase change, especially the solidified and hardened phase change material, is uneven, the comfort is poor, the cycle stability of the phase change material is poor, and the service life is short, and achieves the technical effect that the materials are compounded to play a high-efficiency synergistic effect, and the flexible phase change energy storage soft paste material is suitable for human body heat management.

Description

Technical Field

[0001] This invention relates to the technical field of phase change energy storage materials, and in particular to a flexible phase change energy storage ointment material, its preparation method, and its application. Background Technology

[0002] Phase change energy storage materials (PCEs), as temperature-sensing materials, manage predetermined temperatures and energy by absorbing or releasing latent heat within a specific temperature range (phase change point). Objects implanted with PCEs can sense changes in environmental and internal temperatures and automatically adjust their temperature to a pre-set, reasonable range. This characteristic has led to their widespread application in the field of human thermal management. Currently, the mainstream approach involves combining PCE microcapsules with spinning processes to obtain yarns, fabrics, and clothing suitable for human body temperature.

[0003] However, phase change energy storage materials have not been deeply developed in the field of human thermal management, such as cooling pads, temperature-regulating cushions, and temperature-controlled mattresses, which are in frequent contact with humans in daily life. The main reasons are: first, there is a lack of phase change energy storage materials that are suitable for human thermal management temperature and have low cost and can be applied on a large scale; second, the phase change form of phase change energy storage materials is mainly a solid-liquid phase change. After the liquid phase material releases heat and solidifies into a solid, the surface is hard and uneven, resulting in poor comfort.

[0004] Extensive research indicates that phase change energy storage materials with a phase change temperature (PVT) of around 32 degrees Celsius can meet the needs of both cooling in summer and insulation in winter, making them a suitable material for human thermal management with an ideal PVT temperature. Organic PVT materials such as fatty alcohols and fatty acids are excluded due to their high volatility, strong pungent odor, and potential chemical hazards. While sodium sulfate decahydrate, a common inorganic hydrated salt PVT material, has a PVT point close to 32 degrees Celsius, it is prone to water loss and has poor stability. Disodium hydrogen phosphate dodecahydrate is chemically relatively stable. Existing technology CN202210198907.8 discloses a graphene-modified disodium hydrogen phosphate dodecahydrate hydrated PVT thermal storage material and its preparation method, but its PVT temperature is between 36-37 degrees Celsius, which is clearly unsuitable for human thermal management. Furthermore, it lacks flexibility treatment, and the addition of anti-caking agents only slows down the agglomeration of the solid after the PVT, failing to meet the requirements for human thermal management comfort. In addition, the thermal performance cycle stability of phase change energy storage materials during multiple heat storage and release processes, i.e., the decay of phase change enthalpy, is also a key concern.

[0005] Therefore, it is of great significance to develop a flexible phase change energy storage ointment material that is suitable for human thermal management temperature (around 32 degrees Celsius), has a high degree of comfort in its surface morphology before and after phase change, and has a long lifespan.

[0006] In view of this, the present invention is hereby proposed. Summary of the Invention

[0007] One of the objectives of this invention is to provide a flexible phase change energy storage ointment material that can solve the technical problems of mismatch between the phase change temperature of disodium hydrogen phosphate dodecahydrate and the human body's thermal management temperature, uneven surface and poor comfort after liquid-solid phase change, especially after solidification and hardening, as well as poor cycle stability and short service life of phase change materials.

[0008] The second objective of this invention is to provide a method for preparing a flexible phase change energy storage ointment material.

[0009] The third objective of this invention is to provide an application of a flexible phase change energy storage ointment material.

[0010] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted:

[0011] In one aspect, a flexible phase change energy storage ointment material includes disodium hydrogen phosphate dodecahydrate, water, a crystal structure stabilizer, a phase change morphology modifier, and a phase change temperature regulator.

[0012] The crystal structure stabilizer includes at least one of glycerol, sorbitol, propylene glycol, and water-soluble silicone oil;

[0013] The phase change modifier includes at least one of sodium alginate, gelatin, xanthan gum, water glass, sodium dodecyl sulfonate, calcium chloride, and sodium bicarbonate.

[0014] Furthermore, the phase change temperature regulator includes at least one of potassium chloride, sodium chloride, and ammonium chloride.

[0015] Furthermore, the mass percentage of disodium hydrogen phosphate dodecahydrate in the flexible phase change energy storage ointment material is 65%-75%.

[0016] Furthermore, the water content in the flexible phase change energy storage ointment material is 5%-10% by mass.

[0017] Furthermore, the mass percentage of the crystal structure stabilizer in the flexible phase change energy storage ointment material is 12%-17%.

[0018] Furthermore, the phase change morphology modifier in the flexible phase change energy storage ointment material accounts for 5%-7% by mass.

[0019] Furthermore, the phase change temperature regulator in the flexible phase change energy storage ointment material accounts for 0.5%-1% by mass.

[0020] Secondly, a method for preparing a flexible phase change energy storage ointment material as described in any one of the above claims includes the following steps:

[0021] (a) Disodium hydrogen phosphate dodecahydrate is first premixed with a phase change temperature regulator, melted, and then dissolved in water to obtain an aqueous solution of disodium hydrogen phosphate.

[0022] (b) The aqueous solution of disodium hydrogen phosphate from step (a) is mixed with a crystal structure stabilizer to obtain an oil-water mixed solution;

[0023] (c) The oil-water phase mixture solution from step (b) is mixed with a phase change modifier to obtain the flexible phase change energy storage ointment material.

[0024] Thirdly, the application of any of the above-mentioned flexible phase change energy storage ointment materials in the field of human body thermal management.

[0025] Furthermore, the field of human body thermal management includes cooling pads, temperature-regulating cushions, and / or temperature-controlled mattresses.

[0026] Compared with the prior art, the present invention has at least the following beneficial effects:

[0027] The flexible phase change energy storage ointment material provided by this invention, as a semi-fixed phase change material, utilizes a gel-like three-dimensional network structure constructed by crystal structure stabilizers and phase change morphology modifiers. This ensures that the disodium hydrogen phosphate dodecahydrate crystal grains are uniformly distributed throughout the network space and tightly encapsulated, eliminating crystal precipitation caused by density differences during secondary dissolution or crystallization. This helps suppress phase separation, thereby improving the stability of the material's heat storage performance during long-term thermal cycling. The flexible phase change energy storage ointment material of this invention (after 2000 melting and solidification tests) exhibits small enthalpy changes and good cycling stability. The ointment maintains its softness essentially unchanged. Furthermore, the addition of a phase change temperature regulator in this invention adjusts the phase change temperature of disodium hydrogen phosphate dodecahydrate, lowering it from 36-37 degrees Celsius to approximately 32 degrees Celsius, thus adapting it to the suitable temperature for human thermal management. In summary, through the synergistic effect of the various materials, this invention solves the technical problems of the mismatch between the phase change temperature of disodium hydrogen phosphate dodecahydrate and the human thermal management temperature, the uneven surface and poor comfort of phase change materials after liquid-solid phase change, especially after solidification and hardening, as well as the poor cycle stability and short service life of phase change materials. Detailed Implementation

[0028] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] According to a first aspect of the present invention, a flexible phase change energy storage ointment material is provided, comprising disodium hydrogen phosphate dodecahydrate, water, a crystal structure stabilizer, a phase change morphology modifier, and a phase change temperature regulator.

[0030] Crystal structure stabilizers include, but are not limited to, at least one of glycerol, sorbitol, propylene glycol, and water-soluble silicone oil;

[0031] It should be noted that the use of crystal structure stabilizers is mainly to solve the problems of overcooling and phase separation in disodium hydrogen phosphate dodecahydrate phase change materials. Specifically, compared with the traditional solution of adding nucleating agents and thickeners, this invention starts from the perspective of stabilizing the crystal structure and uses crystal structure stabilizers to solve the problems of overcooling and phase separation in one go by forming a hydrogen bond cross network with the water of crystallization molecules.

[0032] This invention requires only the addition of a crystal structure stabilizer once, making the process simple and requiring few materials. Taking glycerol as an example, its working principle lies in the fact that glycerol itself contains three hydroxyl groups, which have a strong hydrogen bond forming ability. It can form a strong and stable glycerol-water hydrogen bond network with water molecules in disodium hydrogen phosphate dodecahydrate, thereby strongly locking in water, encapsulating disodium hydrogen phosphate crystals, preventing salt-water separation, and effectively inhibiting phase separation. At the same time, glycerol molecules act as heterogeneous nucleation sites, disrupting the homogeneous liquid phase state required for supercooling, which is beneficial for promoting the crystallization of inorganic salt molecules and reducing supercooling. In addition, glycerol, as a gelling agent, can play a role in shaping, moisturizing, and stabilizing the network in the three-dimensional cross network constructed in the later stage together with the phase change modifier.

[0033] Phase change modifiers include, but are not limited to, at least one of sodium alginate, gelatin, xanthan gum, water glass, sodium dodecyl sulfonate, calcium chloride, and sodium bicarbonate;

[0034] It should be noted that by using phase change modifiers, the original clear solid-liquid phase transition morphology of the phase change material can be blurred. That is, above the phase transition point, the material no longer has the high fluidity of a liquid, and below the phase transition point, it no longer cools, solidifies, or hardens. The surface morphology of the material before and after the phase transition point tends to be consistent, becoming a flexible paste material, thereby greatly improving the comfort of the material during use. This is mainly due to the three-dimensional network gelation process of crystal structure stabilizers (such as glycerol) and phase change modifiers (such as sodium alginate). Gelation increases the viscosity of the entire system, greatly reduces fluidity, and increases elasticity. At the same time, the swelling properties of calcium chloride further compensate for the volume shrinkage change of the phase change material during the liquid-solid phase transition, maintaining the consistency of the material morphology before and after the phase transition.

[0035] The material of this invention solidifies into an elastic jelly-like state (visible to the naked eye), making the inorganic material soft and comfortable, and easy to use in daily life, especially in contact with human skin;

[0036] In addition, phase change temperature regulators can be used to adjust the phase change temperature of disodium hydrogen phosphate dodecahydrate, reducing its phase change temperature from 36-37 degrees Celsius to around 32 degrees Celsius, thus adapting it to the appropriate temperature for human body thermal management.

[0037] In summary, through the synergistic effect of various materials, this invention solves the technical problems of the mismatch between the phase change temperature of disodium hydrogen phosphate dodecahydrate and the human body's thermal management temperature, the uneven surface and poor comfort of the phase change material after liquid-solid phase change, especially after solidification and hardening, as well as the poor cycle stability and short service life of the phase change material.

[0038] In a preferred embodiment, the phase transition temperature regulator includes, but is not limited to, at least one of potassium chloride, sodium chloride, and ammonium chloride, which can effectively adjust the phase transition temperature of disodium hydrogen phosphate dodecahydrate. This is mainly achieved through the eutectic effect between inorganic salts, which can reduce the phase transition temperature of disodium hydrogen phosphate dodecahydrate from 36-37 degrees Celsius to about 32 degrees Celsius.

[0039] In a preferred embodiment, the mass percentage of disodium hydrogen phosphate dodecahydrate in the flexible phase change energy storage ointment material can be 65%-75%, with typical but non-limiting mass percentages such as 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, and 75%.

[0040] In a preferred embodiment, the water content in the flexible phase change energy storage ointment material can be 5%-10% by mass, with typical but non-limiting mass contents such as 5%, 6%, 7%, 8%, 9%, and 10%.

[0041] In a preferred embodiment, the mass percentage of the crystal structure stabilizer in the flexible phase change energy storage ointment material can be 12%-17%, with typical but non-limiting mass percentages being, for example, 12%, 13%, 14%, 15%, 16%, and 17%.

[0042] In a preferred embodiment, the mass percentage of the phase change modifier in the flexible phase change energy storage ointment material can be 5%-7%, with typical but non-limiting mass percentages being, for example, 5%, 6%, and 7%.

[0043] In a preferred embodiment, the mass percentage of the phase change temperature regulator in the flexible phase change energy storage ointment material can be 0.5%-1%, with typical but non-limiting mass percentages such as 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, and 1%.

[0044] According to a second aspect of the present invention, a method for preparing the flexible phase change energy storage ointment material as described in any one of the above claims is provided, comprising the following steps:

[0045] (a) Disodium hydrogen phosphate dodecahydrate is first premixed with a phase change temperature regulator, melted, and then dissolved in water to obtain an aqueous solution of disodium hydrogen phosphate.

[0046] Adding an appropriate amount of purified water during the melting and stirring process before adding the crystal structure stabilizer can effectively compensate for the loss of crystal water in the disodium hydrogen phosphate dodecahydrate material; at the same time, precise temperature control, strict control of the time, and maintaining a sealed environment can all effectively control the loss of crystal water.

[0047] (b) The aqueous solution of disodium hydrogen phosphate from step (a) is mixed with a crystal structure stabilizer to obtain an oil-water mixed solution;

[0048] (c) The oil-water phase mixture solution from step (b) is mixed with a phase change modifier to obtain a flexible phase change energy storage ointment material.

[0049] According to a third aspect of the present invention, an application of the flexible phase change energy storage ointment material described in any of the preceding claims in the field of human thermal management is provided.

[0050] In this invention, the field of human body thermal management includes, but is not limited to, cooling pads, temperature-regulating cushions, and / or temperature-controlled mattresses.

[0051] The present invention will be further illustrated by the following examples. Unless otherwise specified, the materials in the examples are prepared according to existing methods or purchased directly from the market.

[0052] Example 1

[0053] A method for preparing a flexible phase change energy storage ointment material includes the following steps:

[0054] (a) Using 700g of disodium hydrogen phosphate dodecahydrate as the basic phase change material, it was premixed with 7.5g of sodium chloride (phase change temperature regulator) and placed in a reactor. After heating in a 65°C water bath for 30 minutes until the material was completely melted, 80g of pure water was added and stirred for 2 minutes to obtain a homogeneous aqueous solution of disodium hydrogen phosphate.

[0055] (b) Add 150g of glycerol (crystal structure stabilizer) to the aqueous solution of disodium hydrogen phosphate in step (a), stir for 10min, and obtain a solution with uniform oil-water phase mixture;

[0056] (c) Add 40g of sodium alginate (phase change modifier) ​​and 22.5g of calcium chloride to the solution obtained in step (b), stir for 10 minutes to allow the reaction to proceed fully, and obtain a paste-like material with high viscosity and low fluidity, which is the flexible phase change energy storage ointment material.

[0057] Example 2

[0058] A method for preparing a flexible phase change energy storage ointment material includes the following steps:

[0059] (a) Using 650g of disodium hydrogen phosphate dodecahydrate as the basic phase change material, it was premixed with 10g of potassium chloride (phase change temperature regulator) and placed in a reactor. After heating in a 65°C water bath for 25 minutes until the material was completely melted, 100g of pure water was added and stirred for 2 minutes to obtain a homogeneous aqueous solution of disodium hydrogen phosphate.

[0060] (b) Add 170g of sorbitol (crystal structure stabilizer) to the aqueous solution of disodium hydrogen phosphate in step (a), stir for 15min, and obtain a solution with uniform oil-water phase mixture;

[0061] (c) Add 50g of xanthan gum (phase change modifier) ​​and 20g of calcium chloride to the solution obtained in step (b), stir for 15min, and react fully to obtain a paste material with high viscosity and low fluidity, which is the flexible phase change energy storage ointment material.

[0062] Example 3

[0063] A method for preparing a flexible phase change energy storage ointment material includes the following steps:

[0064] (a) Using 750g of disodium hydrogen phosphate dodecahydrate as the basic phase change material, it was premixed with 6g of ammonium chloride (phase change temperature regulator) and placed in a reactor. After heating in a 65°C water bath for 35 minutes until the material was completely melted, 60g of pure water was added and stirred for 2 minutes to obtain a homogeneous aqueous solution of disodium hydrogen phosphate.

[0065] (b) Add 120g of water-soluble silicone oil (crystal structure stabilizer) to the sodium hydrogen phosphate aqueous solution in step (a), stir for 10min, and obtain a solution with uniform oil-water phase mixture;

[0066] (c) Add 50g of gelatin (phase change modifier) ​​and 20g of calcium chloride to the solution obtained in step (b), stir for 12 minutes to allow the reaction to proceed fully, and obtain a paste-like material with high viscosity and low fluidity, which is the flexible phase change energy storage ointment material.

[0067] Example 4

[0068] The only difference between this embodiment and Embodiment 1 is that, in step (b), glycerol is replaced with an equal amount of propylene glycol.

[0069] The remaining steps and parameters are the same as in Example 1, resulting in a flexible phase change energy storage ointment material.

[0070] Example 5

[0071] The only difference between this embodiment and Embodiment 1 is that, in step (c), an equal amount of water glass is used to replace sodium alginate.

[0072] The remaining steps and parameters are the same as in Example 1, resulting in a flexible phase change energy storage ointment material.

[0073] Example 6

[0074] The only difference between this embodiment and Embodiment 1 is that, in step (c), sodium alginate is replaced with an equal amount of sodium dodecyl sulfonate.

[0075] The remaining steps and parameters are the same as in Example 1, resulting in a flexible phase change energy storage ointment material.

[0076] Comparative Example 1

[0077] This comparative example provides a phase change thermal storage material, which is prepared by the preparation method of graphene-modified disodium hydrogen phosphate dodecahydrate hydrated phase change thermal storage material disclosed in CN202210198907.8.

[0078] Comparative Example 2

[0079] The only difference between this comparative example and Example 1 is that sodium chloride was not added in step (a), i.e., no phase change temperature regulator was added.

[0080] The remaining steps and parameters are the same as in Example 1, resulting in a flexible phase change energy storage ointment material.

[0081] Comparative Example 3

[0082] The only difference between this comparative example and Example 1 is that sodium alginate and calcium chloride were not added in step (c), i.e., no phase change modifier was added.

[0083] The remaining steps and parameters are the same as in Example 1, resulting in a flexible phase change energy storage ointment material.

[0084] Experimental Example 1

[0085] The characterization results of the thermal properties, material state, and material feel of the materials obtained in Examples 1-6 and Comparative Examples 1-3 are shown in Table 1.

[0086] As shown in Table 1, compared with Examples 1-6, the phase change enthalpy of the material obtained in Comparative Example 1 is higher, and its phase change temperature, phase change morphology, and material feel cannot meet the requirements of human thermal management for phase change materials. Compared with Example 1, the material obtained in Comparative Example 2, due to the absence of a phase change temperature regulator, although meeting the requirements of human thermal management materials in terms of phase change morphology and material feel, has an excessively high phase change temperature that cannot match the needs of human thermal management. Compared with Example 1, the material obtained in Comparative Example 3, due to the absence of a phase change morphology modifier, results in a solid particle shape after cooling and solidification, with a rough and prickly feel, and cannot meet the requirements of human thermal management materials in terms of material morphology and material feel.

[0087] Table 1

[0088]

[0089] Experimental Example 2

[0090] The material obtained in Example 1 was subjected to a thermal cycling stability test, with 2000 tests conducted. The results are shown in Table 2.

[0091] As shown in Table 2, the effective enthalpy of the material obtained in Example 1 can still be maintained at more than 95% of the initial phase transition enthalpy after 2000 phase transitions. The material state before and after the cycle did not change significantly, and it is considered to be a jelly-like paste material.

[0092] Table 2

[0093]

[0094] In summary, the flexible phase change energy storage ointment material of this invention uses disodium hydrogen phosphate dodecahydrate as the main phase change material and crystal structure stabilizer, phase change morphology modifier and phase change temperature regulator as auxiliary materials. The main and auxiliary materials work synergistically to ensure that the phase change temperature, phase change enthalpy, phase change morphology and feel of the material can meet the performance requirements of products in the field of human body thermal management, such as cooling pads, temperature-regulating cushions and / or temperature-controlled mattresses.

[0095] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A flexible phase change energy storage ointment material, characterized in that, It includes disodium hydrogen phosphate dodecahydrate, water, crystal structure stabilizer, phase change morphology modifier, and phase change temperature regulator; The crystal structure stabilizer includes at least one of glycerol, sorbitol, propylene glycol, and water-soluble silicone oil; The phase change modifier includes at least one of sodium alginate, gelatin, xanthan gum, water glass, sodium dodecyl sulfonate, calcium chloride, and sodium bicarbonate. The phase change temperature regulator includes at least one of potassium chloride, sodium chloride, and ammonium chloride; The mass percentage of disodium hydrogen phosphate dodecahydrate in the flexible phase change energy storage ointment material is 65%-75%. The water content in the flexible phase change energy storage ointment material is 5%-10% by mass. The mass percentage of the crystal structure stabilizer in the flexible phase change energy storage ointment material is 12%-17%. The phase change morphology modifier in the flexible phase change energy storage ointment material accounts for 5%-7% by mass; The phase change temperature regulator in the flexible phase change energy storage ointment material accounts for 0.5%-1% by mass.

2. A method for preparing the flexible phase change energy storage ointment material according to claim 1, characterized in that, Includes the following steps: (a) Disodium hydrogen phosphate dodecahydrate is first premixed with a phase change temperature regulator, melted, and then dissolved in water to obtain an aqueous solution of disodium hydrogen phosphate. (b) The aqueous solution of disodium hydrogen phosphate from step (a) is mixed with a crystal structure stabilizer to obtain an oil-water mixed solution; (c) The oil-water phase mixture solution from step (b) is mixed with a phase change modifier to obtain the flexible phase change energy storage ointment material.

3. The application of the flexible phase change energy storage ointment material according to claim 1 in the preparation of cooling pads, temperature-regulating cushions and / or temperature-controlled mattresses.

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