A preparation method of a glue-free self-bonding phase change energy storage material

Abstract

The invention discloses a method for preparing a glue-free self-bonding phase-change energy storage material, comprising: dissolving polystyrene particles to obtain a polystyrene solution, adding tetradecanol to the polystyrene solution, stirring until uniformly dispersed, and obtaining a mixture of the tetradecanol and the polystyrene solution; adding the mixture to a surfactant solution to form microcapsules, washing and drying, placing a multi-walled carbon nanotube spinning solution and tetradecanol microcapsules made from polystyrene into a reaction vessel, and uniformly mixing and reacting them; injecting the reaction product into a spinner, uniformly spraying it out, stacking it together, weaving it up and down with silver nanowires, filling it with wood powder, and pressing it into shape, thereby effectively improving the thermal conductivity, avoiding heat loss during heat transfer, and effectively avoiding the occurrence of cracking and leakage problems of the object caused by phase change.

Description

Technical Field

[0001] The present invention relates to the field of phase change energy storage materials, and in particular to a method for preparing a glue-free self-bonding phase change energy storage material. Background Art

[0002] Phase change energy storage materials are materials that can absorb and release large amounts of heat during phase changes. They are typically substances with specific phase transition temperatures, such as when they change from solid to liquid or from liquid to gas. During this phase change, these materials can absorb or release large amounts of heat, making them suitable for use as energy storage materials. Phase change energy storage materials are primarily used in the construction, electronics, and automotive industries for regulating indoor temperatures, maintaining the stability of electronic devices, and improving the efficiency of automotive engines.

[0003] However, the existing phase change energy storage materials have uneven heat transfer between the outer and inner layers when absorbing heat and undergoing phase change. As a result, when the phase change occurs, the outer layer has absorbed heat and expanded, but the inner layer cannot absorb heat and undergo phase change. The long-term expansion and contraction causes the material to deform and crack, reducing its service life. Summary of the Invention

[0004] The present invention overcomes the deficiencies of the prior art and provides a method for preparing a glue-free self-bonding phase-change energy storage material.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a method for preparing a glue-free self-bonding phase change energy storage material, comprising:

[0006] S1: dissolving polystyrene particles in a solvent to obtain a polystyrene solution, adding tetradecanol to the polystyrene solution, and stirring until uniformly dispersed to obtain a mixture of tetradecanol and the polystyrene solution;

[0007] S2: adding the mixture of tetradecanol and polystyrene solution to the surfactant solution to form microcapsules, and washing with deionized water and drying;

[0008] S3: mixing and stirring the multi-walled carbon nanotubes and the organic solvent, adding a surfactant, continuing stirring, and centrifuging to obtain a multi-walled carbon nanotube spinning solution;

[0009] S4: placing the multi-walled carbon nanotube spinning solution and the polystyrene tetradecanol microcapsules into a reaction container and stirring them to uniformly mix and react;

[0010] S5: The S4 reaction product is injected into the spinner, and is evenly sprayed out through the rotating cylinder and nozzle. After stretching and drying operations, the S4 reaction product forms a crisscross network structure;

[0011] S6: Repeat S1-S5 operations to obtain several S5 products, stack them together, weave them up and down with silver nanowires, fill them with wood powder, and press them into shape.

[0012] In a preferred embodiment of the present invention, the solvent in S1 is acetone or dichloromethane, which is stirred after being added until it is dissolved.

[0013] In a preferred embodiment of the present invention, the stirring speed of the stirring operation to uniformly disperse in S1 is 30 r / min-40 r / min.

[0014] In a preferred embodiment of the present invention, the mixture of tetradecanol and polystyrene solution is added to the surfactant solution in S2 by dropwise addition.

[0015] In a preferred embodiment of the present invention, the dripping speed is 15 times / min-20 times / min.

[0016] In a preferred embodiment of the present invention, the stirring parameter in S3 is 35r / min-40r / min, and the surfactant is added continuously while stirring; the organic solvent is selected from xylene or toluene, and the surfactant is selected from sulfonic acid.

[0017] In a preferred embodiment of the present invention, the uniform mixing reaction in S4 is a cross-linking reaction, forming covalent bonds between the multi-walled carbon nanotubes and the tetradecanol microcapsules made of polystyrene.

[0018] In a preferred embodiment of the present invention, the ratio of tetradecanol to polystyrene in S1 is 2:1.

[0019] In a preferred embodiment of the present invention, the ratio of the mixture of tetradecanol and polystyrene solution to the surfactant in S2 is 1:6.

[0020] In a preferred embodiment of the present invention, the ratio of multi-walled carbon nanotubes, organic solvent and surfactant in S3 is 1:3:6.

[0021] The present invention solves the defects existing in the background technology and has the following beneficial effects:

[0022] (1) The present invention provides a method for preparing a glue-free self-bonding phase change energy storage material, in which multi-walled carbon nanotubes and silver nanowires are woven into a three-dimensional frame, capsules with polystyrene as the shell and tetradecanol as the core are uniformly cross-linked and mixed, and then filled and pressed with wood powder. The good thermal conductivity of the multi-walled carbon nanotubes, silver nanowires and polystyrene is used to transfer heat to achieve the phase change energy storage effect of tetradecanol, effectively improving the thermal conductivity efficiency, avoiding the loss of heat during the heat transfer process, and at the same time, effectively avoiding the occurrence of cracking and leakage problems of objects caused by phase change.

[0023] (2) The present invention provides a method for preparing a glue-free self-bonding phase change energy storage material, in which multi-walled carbon nanotubes and silver nanowires are woven into a three-dimensional frame, and then wood powder is used to fill and press the frame. Since both multi-walled carbon nanotubes and silver nanowires have good thermal conductivity, the multi-walled carbon nanotubes and silver nanowires can quickly and evenly conduct and dissipate heat when heat changes. In addition, since capsules with polystyrene as the shell and tetradecyl alcohol as the core are evenly distributed on the multi-walled carbon nanotubes, the tetradecyl alcohol inside and outside are evenly heated, effectively avoiding the situation in the existing phase change energy storage material where the outside is heated and phase changes, but the inside is not heated, and the material deforms and cracks due to the long-term expansion and contraction, thereby improving the service life of the material.

[0024] (3) The present invention provides a method for preparing a glue-free self-bonding phase change energy storage material, which comprises preparing microcapsules with polystyrene as a shell and tetradecanol as a core, uniformly mixing the microcapsules with a multi-walled carbon nanotube spinning solution, and then allowing the polystyrene and the multi-walled carbon nanotube spinning solution to undergo a cross-linking reaction, thereby forming a covalent bond between the outer shell of the microcapsule and the multi-walled carbon nanotubes and integrating them into one, and finally performing spinning and weaving to form a phase change energy storage material with tetradecanol as the main phase change energy storage material and various heat conductive materials as a uniform three-dimensional shell frame, thereby effectively preventing leakage after the tetradecanol undergoes phase change, which would result in poor phase change energy storage performance.

[0025] (4) The present invention provides a method for preparing a glue-free self-binding phase change energy storage material. By using sorbate as a surfactant solution of a mixture of tetradecyl alcohol and polystyrene solution in the preparation of microcapsules, sorbate can be used to enhance the dispersibility and stability of polystyrene particles. At the same time, the size and shape of the microcapsules can be adjusted, so that the prepared microcapsules have better controllability and consistency. Therefore, microcapsules of different sizes and shapes can be prepared according to different needs. Moreover, since polystyrene has good thermal conductivity, when tetradecyl alcohol is used as the capsule core and polystyrene is used as the shell layer, the thermal conductivity, controllability and consistency of the capsule are taken into account at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments described in the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive efforts.

[0027] Figure 1 It is a three-dimensional structural diagram of a preferred embodiment of the present invention; DETAILED DESCRIPTION

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0029] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0030] like Figure 1 As shown, a method for preparing a glue-free self-bonding phase change energy storage material comprises:

[0031] S1: dissolving polystyrene particles in a solvent to obtain a polystyrene solution, adding tetradecanol to the polystyrene solution, and stirring until uniformly dispersed to obtain a mixture of tetradecanol and the polystyrene solution;

[0032] In a preferred embodiment of the present invention, the solvent in S1 is acetone or dichloromethane, which is stirred after being added until it is dissolved.

[0033] In a preferred embodiment of the present invention, the stirring speed of the stirring operation to uniformly disperse in S1 is 30 r / min-40 r / min.

[0034] It should be noted that the ratio of tetradecanol to polystyrene solution is 2:1. The preparation of polystyrene solution is specifically as follows: prepare raw materials: polystyrene particles and solvent. Since the particle size and molecular weight of polystyrene particles will affect the viscosity and solubility of the prepared solution, commonly used solvents include organic solvents such as benzene, toluene, and xylene; add the solvent to the reactor and heat it to an appropriate temperature, usually between 70°C and 120°C; gradually add the polystyrene particles to the reactor and stir continuously to fully dissolve them. It should be noted that the addition speed and amount of polystyrene particles should be controlled within a certain range to avoid problems such as agglomeration and incomplete dissolution; when the polystyrene particles are completely dissolved, continue heating and keeping warm for a period of time to ensure the uniformity and stability of the solution; filter the prepared polystyrene solution to remove impurities and undissolved polystyrene particles to obtain a pure solution; the polystyrene solution prepared in this way has good thermal conductivity and can quickly conduct heat away with low loss when receiving heat.

[0035] S2: adding the mixture of tetradecanol and polystyrene solution to the surfactant solution to form microcapsules, and washing with deionized water and drying;

[0036] In a preferred embodiment of the present invention, the mixture of tetradecanol and polystyrene solution is added to the surfactant solution in S2 by dropwise addition.

[0037] In a preferred embodiment of the present invention, the ratio of the mixture of tetradecanol and polystyrene solution to the surfactant in S2 is 1:6.

[0038] In a preferred embodiment of the present invention, the dripping speed is 15 times / min-20 times / min.

[0039] It should be noted that the ratio of the mixture of tetradecanol and polystyrene solution to the surfactant is 1:6, and the mixture of tetradecanol and polystyrene solution is added dropwise to the surfactant solution, wherein the surfactant solution is generally a non-ionic surfactant such as polysorbate 80 (Tween 80) or sorbate (Span 80), preferably sorbate (Span 80). Sorbitate (Span 80) has good emulsification, dispersion, stability, and biocompatibility. In microcapsule preparation, Span 80 can be used to enhance the dispersibility and stability of polystyrene particles, while also adjusting the size and shape of the microcapsules, resulting in better controllability and consistency of the prepared microcapsules. Therefore, microcapsules of different sizes and shapes can be prepared according to different needs. Moreover, since polystyrene has good thermal conductivity, when tetradecanol is used as the capsule core and polystyrene is used as the shell, the thermal conductivity, controllability, and consistency of the capsule are taken into account.

[0040] S3: mixing and stirring the multi-walled carbon nanotubes and the organic solvent, adding a surfactant, continuing stirring, and centrifuging to obtain a multi-walled carbon nanotube spinning solution;

[0041] In a preferred embodiment of the present invention, the ratio of multi-walled carbon nanotubes, organic solvent and surfactant in S3 is 1:3:6.

[0042] In a preferred embodiment of the present invention, the stirring parameter in S3 is 35r / min-40r / min, and the surfactant is added continuously while stirring; the organic solvent is selected from xylene or toluene, and the surfactant is selected from sulfonic acid.

[0043] It should be noted that the ratio of multi-walled carbon nanotubes, organic solvent and surfactant is 1:3:6, sulfonic acid can make the surface of multi-walled carbon nanotubes have a negative charge, thereby forming a strong electrostatic attraction between the multi-walled carbon nanotubes and water molecules, preventing the multi-walled carbon nanotubes from aggregation, precipitation or stratification during the preparation process, thereby enhancing the dispersibility and stability of the multi-walled carbon nanotubes, and sulfonic acid can form a strong chemical bond with the surface of the multi-walled carbon nanotubes, thereby increasing the interaction force between the multi-walled carbon nanotubes and other materials, adjusting the viscosity and rheological properties of the spinning solution, so that the prepared spinning solution has better processability and applicability; the multi-walled carbon nanotube spinning solution prepared in this way has good viscosity and can generate a strong interaction force when mixed with tetradecanol microcapsules.

[0044] S4: placing the multi-walled carbon nanotube spinning solution and the polystyrene tetradecanol microcapsules into a reaction container and stirring them to uniformly mix and react;

[0045] In a preferred embodiment of the present invention, the uniform mixing reaction in S4 is a cross-linking reaction, forming covalent bonds between the multi-walled carbon nanotubes and the polystyrene tetradecanol microcapsules.

[0046] It should be noted that the ratio of multi-walled carbon nanotube spinning solution to polystyrene tetradecanol microcapsules is 1:1. When the multi-walled carbon nanotube spinning solution and polystyrene tetradecanol microcapsules are placed in a reaction vessel for stirring and mixing reaction, a cross-linking reaction will occur between the multi-walled carbon nanotubes and the polystyrene tetradecanol microcapsules, thereby forming a covalent bond between the multi-walled carbon nanotubes and the polystyrene tetradecanol microcapsules, so that the microcapsules are completely integrated into the multi-walled carbon nanotubes. Moreover, since the multi-walled carbon nanotube spinning solution has a good viscosity, it can generate a strong interaction force when mixed with the tetradecanol microcapsules, thereby completely adsorbing the microcapsules onto the multi-walled carbon nanotubes.

[0047] S5: The S4 reaction product is injected into the spinner, and is evenly sprayed out through the rotating cylinder and nozzle. After stretching and drying operations, the S4 reaction product forms a crisscross network structure;

[0048] In a preferred embodiment of the present invention, the ratio of tetradecanol to polystyrene in S1 is 2:1.

[0049] It should be noted that the mesh formed by evenly ejecting multi-walled carbon nanotubes through a spinner and then stretching and drying is a mesh-like braided fabric formed by mixing multi-walled carbon nanotubes horizontally and vertically and then overlapping and weaving them vertically.

[0050] S6: Repeat S1-S5 operations to obtain several S5 products, stack them together, weave them up and down with silver nanowires, fill them with wood powder, and press them into shape.

[0051] It should be noted that 3-5 multi-walled carbon nanotube braids are stacked and placed, and then silver nanowires are used to weave them together, that is, they are passed through a corner of the multi-walled carbon nanotube braid at the bottom, passed through to the multi-walled carbon nanotube braid at the top, and then horizontally offset to one side for a certain distance from the exit position and penetrated downward again until it exits from the bottom, and then penetrated and penetrated up and down to the other end, and then longitudinally offset and penetrated and penetrated up and down again until the last end, so that the braid is completely fixed, and finally the braid is filled with wood powder and pressed into shape; the silver nanowire is sprayed. The preparation method is specifically as follows: preparing a spray solution: mixing silver nanowires (AgNWs) and an organic solvent (such as isopropyl alcohol, chloroform, methyl chloride, etc.), and adding a surfactant (such as sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, etc.) to prepare a spray solution; cleaning and surface treating the surface of the substrate to be sprayed to improve the adhesion and uniformity of the spray liquid on the substrate surface; adding the spray solution to a spray gun or sprayer, and spraying it evenly on the substrate surface at an appropriate spraying distance and pressure to form silver nanowires; drying the sprayed substrate to remove the solvent and surfactant, so that the silver nanowires are stably fixed on the substrate surface.

[0052] Example 1

[0053] The polystyrene particles are dissolved to obtain a polystyrene solution, tetradecanol is added to the polystyrene solution, wherein the ratio of tetradecanol to the polystyrene solution is 2:1, and the mixture is stirred until uniformly dispersed at a stirring speed of 30r / min-40r / min to obtain a mixture of tetradecanol and the polystyrene solution; the mixture of tetradecanol and the polystyrene solution is dripped into a surfactant solution at a dripping speed of 15 times / min-20 times / min, and the ratio of the mixture of tetradecanol and the polystyrene solution to the surfactant is 1:6, thereby forming microcapsules, and the mixture is washed with deionized water and dried; multi-walled carbon nanotubes and an organic solvent are mixed and stirred at a stirring speed of 35r / min-40r / min, and the surfactant is added. The method comprises the following steps: adding a surfactant, continuously stirring, and centrifuging to obtain a multi-walled carbon nanotube spinning solution, wherein the ratio of the multi-walled carbon nanotubes, the organic solvent, and the surfactant is 1:3:6; placing the multi-walled carbon nanotube spinning solution and polystyrene tetradecanol microcapsules in a ratio of 1:1 into a reaction vessel, stirring to uniformly mix and react; injecting the reaction product into a spinner, uniformly spraying it out through a rotating cylinder and a nozzle, and forming the reaction product into a criss-cross network structure through stretching and drying operations; repeating the operation to obtain several products, stacking them together, weaving them up and down with silver nanowires, filling them with wood powder, and pressing them into shape to obtain a phase change energy storage material.

[0054] Control group 1 (blank group)

[0055] The polystyrene particles are dissolved to obtain a polystyrene solution, and tetradecanol is added to the polystyrene solution, wherein the ratio of tetradecanol to the polystyrene solution is 2:1, and the mixture is stirred until uniformly dispersed at a stirring speed of 30r / min-40r / min to obtain a mixture of tetradecanol and polystyrene solution; the mixture of tetradecanol and polystyrene solution is dripped into a surfactant solution at a dripping speed of 15 times / min-20 times / min, and the ratio of the mixture of tetradecanol and polystyrene solution to the surfactant is 1:6, so as to form microcapsules, and the microcapsules are washed and dried with deionized water; multi-walled carbon nanotubes and an organic solvent are mixed and stirred at a stirring speed of 35r / min-40r / min, and a surfactant is added at the same time, the stirring is continued, and the microcapsules are centrifuged to obtain a multi-walled carbon nanotube spinning solution, wherein the ratio of the multi-walled carbon nanotubes, the organic solvent and the surfactant is 1:3:6; wood powder is then used for filling and pressing to obtain a phase change energy storage material.

[0056] Test conclusion: During the phase change process of this phase change energy storage material, the internal and external parts are heated unevenly. When the phase change material on the outside has completed the phase change, some parts inside have not yet undergone phase change, resulting in inconsistent stress and deformation degrees inside and outside. After repeated tests, the material showed obvious deformation and cracking, and due to its low thermal conductivity, a large amount of energy will be lost during the energy storage process.

[0057] Comparative Example 1

[0058] The polystyrene particles are dissolved to obtain a polystyrene solution, tetradecanol is added to the polystyrene solution, wherein the ratio of tetradecanol to the polystyrene solution is 2:1, and the mixture is stirred until uniformly dispersed at a stirring speed of 30r / min-40r / min to obtain a mixture of tetradecanol and the polystyrene solution; the mixture of tetradecanol and the polystyrene solution is dripped into a surfactant solution at a dripping speed of 15 times / min-20 times / min, and the ratio of the mixture of tetradecanol and the polystyrene solution to the surfactant is 1:6, thereby forming microcapsules, and the mixture is washed with deionized water and dried; multi-walled carbon nanotubes and an organic solvent are mixed and stirred at a stirring speed of 35r / min-40r / min, and the surfactant is added. The method comprises the following steps: adding a surfactant, continuously stirring, and centrifuging to obtain a multi-walled carbon nanotube spinning solution, wherein the ratio of the multi-walled carbon nanotubes, the organic solvent, and the surfactant is 1:3:6; placing the multi-walled carbon nanotube spinning solution and polystyrene tetradecanol microcapsules in a ratio of 1:1 into a reaction vessel, and stirring to uniformly mix and react; injecting the reaction product into a spinner, uniformly spraying it out through a rotating cylinder and a nozzle, and forming the reaction product into a criss-cross network structure through stretching and drying operations; repeating the operation to obtain several products, stacking them together, weaving them up and down with silver nanowires, filling them with wood powder, and pressing them into shape to obtain a phase change energy storage material.

[0059] Test conclusion: This phase change energy storage material is heated evenly inside and outside. When the phase change material on the outside undergoes phase change, the inside also undergoes phase change, so that the overall force on the inside and outside of the material is evenly distributed. After repeated experiments, the material did not deform or crack, and the inside was also able to undergo phase change energy storage, avoiding energy loss.

[0060] The above description is based on the ideal embodiment of the present invention. Based on the above description, relevant personnel can make various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the content of the specification and must be determined according to the scope of the claims.

Claims

1. A method for preparing a glue-free self-bonding phase change energy storage material, characterized in that: include: S1: dissolving polystyrene particles in a solvent to obtain a polystyrene solution, adding tetradecanol to the polystyrene solution, and stirring until uniformly dispersed to obtain a mixture of tetradecanol and the polystyrene solution; S2: adding the mixture of tetradecanol and polystyrene solution to a surfactant solution to form microcapsules, washing and drying; S3: mixing and stirring the multi-walled carbon nanotubes and the organic solvent, adding a surfactant, continuing stirring, and centrifuging to obtain a multi-walled carbon nanotube spinning solution; S4: uniformly mixing the multi-walled carbon nanotube spinning solution and the microcapsules to react; S5: The S4 reaction product is injected into the spinner, and is evenly sprayed out through the rotating cylinder and nozzle. After stretching and drying operations, the S4 reaction product forms a crisscross network structure; S6: Repeat S1-S5 to obtain several S5 products, stack them together, weave them up and down with silver nanowires, fill them with wood powder, and press them into shape; In S2, the mixture of tetradecanol and polystyrene solution is added to the surfactant solution by dropwise addition, wherein the surfactant solution is a non-ionic surfactant of polysorbate 80 or sorbate; The dripping speed is 15 times / min-20 times / min.

2. The method for preparing a glue-free self-bonding phase change energy storage material according to claim 1, characterized in that: The solvent in S1 is acetone or dichloromethane, which is added and stirred until it is dissolved.

3. The method for preparing a glue-free self-bonding phase change energy storage material according to claim 1, characterized in that: The stirring speed of the stirring operation to uniform dispersion in S1 is 30 r / min-40 r / min.

4. The method for preparing a glue-free self-bonding phase change energy storage material according to claim 1, characterized in that: The stirring parameter in S3 is 35 r / min-40 r / min, and the surfactant is added continuously while stirring; the organic solvent is selected from xylene or toluene, and the surfactant is selected from sulfonic acid.

5. The method for preparing a glue-free self-bonding phase change energy storage material according to claim 1, characterized in that: The uniform mixing reaction in S4 is a cross-linking reaction, forming covalent bonds between the multi-walled carbon nanotubes and the microcapsules.

6. The method for preparing a non-adhesive self-bonding phase change energy storage material according to claim 1, characterized in that: In the S1, the ratio of tetradecanol to polystyrene is 2:

1.

7. The method for preparing a non-adhesive self-bonding phase change energy storage material according to claim 1, characterized in that: In the S2, the ratio of the mixture of tetradecanol and polystyrene solution to the surfactant is 1:

6.

8. The method for preparing a glue-free self-bonding phase change energy storage material according to claim 1, characterized in that: In the S3, the ratio of multi-walled carbon nanotubes, organic solvent and surfactant is 1:3:6.

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