Rapid cooling type composite phase change material and preparation method thereof
Composite phase change materials were prepared by combining matrix phase change materials with high thermal conductivity fillers, which solved the problem of slow cooling rate of phase change materials, achieved a balance between rapid cooling and long-term heat preservation, and is easy to industrialize.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ZHENGZHOU UNIV
- Filing Date
- 2025-12-22
- Publication Date
- 2026-05-12
AI Technical Summary
Existing phase change materials have slow cooling rates, and the addition of thermally conductive agents results in poor compatibility, unstable performance, reduced latent heat of phase change, and high costs.
The composite phase change material is prepared by combining a matrix phase change material with a high thermal conductivity filler through mechanical stirring and ultrasonic dispersion. The high thermal conductivity filler is selected from metal powder and carbon materials, with a mass percentage of 0.5% to 10%, forming a thermally conductive network.
It significantly improves the cooling rate, retains the latent heat of phase change, shortens the cooling time by 30%-70%, forms a three-dimensional heat conduction network, and has a simple process, low cost, and is easy to industrialize.
Smart Images
Figure CN122012027A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of thermal energy storage and temperature control materials technology, specifically relating to a composite phase change material with rapid cooling characteristics and its preparation method. Background Technology
[0002] Overview of Phase Change Materials: Phase change materials (PCMs) are substances that utilize the property of absorbing or releasing a large amount of latent heat during a phase change process while maintaining a relatively constant temperature. They are widely used for heat dissipation in electronic devices, building energy conservation, textiles and clothing, cold chain transportation, and temperature control appliances.
[0003] Traditional phase change materials, especially solid-liquid phase change materials (such as paraffin, hydrated salts, and fatty acids), while possessing high latent heat of phase change, generally suffer from low thermal conductivity. This results in slow cooling rates in applications requiring heat release (i.e., cooling from a liquid state to solidification), as the internal heat of the phase change material cannot be quickly dissipated. For example, in the heat dissipation of electronic devices, slow cooling prolongs the high-temperature operating time of the equipment, affecting performance and lifespan; in applications such as temperature-controlled coasters, it leads to excessively long initial cooling times, resulting in a poor user experience.
[0004] To address the thermal conductivity issue, existing technologies have attempted to incorporate thermally conductive materials such as metal foams and carbon materials into phase change materials. However, these methods may have the following problems: 1. The additives have poor compatibility with the phase change materials, and are prone to sedimentation or agglomeration, resulting in unstable performance; 2. The introduction of additives may significantly reduce the latent heat of phase change of phase change materials, affecting their core heat storage / insulation capabilities. 3. Some additives (such as certain forms of carbon nanotubes) are expensive and have complex preparation processes, making them difficult to industrialize. Summary of the Invention
[0005] The technical problem to be solved by this invention is: how to overcome the defect of slow cooling rate of existing phase change materials, and provide a composite phase change material that has significant rapid cooling characteristics while maintaining high latent heat of phase change.
[0006] Another objective of this invention is to provide a method for preparing the above-mentioned composite phase change material, which is simple in process, low in cost, and easy to scale up for production.
[0007] To solve the above problems, the present invention is achieved through the following technical solution: A rapid cooling composite phase change material, characterized in that it is composed of a matrix phase change material and a high thermal conductivity filler; The matrix phase change material is a material that undergoes a solid-liquid phase change within the target phase change temperature range, and is selected from one or more mixtures of paraffin, lauric acid, and n-octadecane. The target phase change temperature is any temperature point or range between 25°C and 60°C. The high thermal conductivity filler is a metal powder and / or carbon material with a high thermal conductivity. The metal powder is selected from one or more of copper powder, aluminum powder, silver powder, and nickel powder; The carbon material can be selected from one or more of graphene, expanded graphite, carbon nanotubes, and graphite powder; The high thermal conductivity filler is present in the composite phase change material at a mass percentage of 0.5% to 10%.
[0008] The metal powder is in the form of spheres, flakes or dendrites, and the particle size range is preferably 1μm to 100μm.
[0009] The high thermal conductivity filler has a mass percentage of 1% to 5% in the composite phase change material.
[0010] A method for preparing a rapidly cooling composite phase change material includes the following steps: Step 1: Pretreatment: The matrix phase change material is heated and melted into a liquid state at 60℃~80℃; the high thermal conductivity filler is vacuum dried at 80℃~100℃ for 2-4 hours; Step 2: Mixing: The dried high thermal conductivity filler is slowly added to the liquid matrix phase change material in batches, and mechanical stirring is carried out continuously under constant temperature conditions; Step 3: Dispersion: While stirring, ultrasonic treatment is applied to ensure that the high thermal conductivity filler is uniformly dispersed in the liquid phase and to prevent agglomeration. Step 4: Molding: Inject the uniformly mixed slurry into the mold, allow it to cool naturally or under programmed temperature control to room temperature, and solidify to obtain the rapid cooling composite phase change material.
[0011] 5. The method for preparing a rapidly cooling composite phase change material according to claim 4, characterized in that: the ultrasonic treatment power is 300W-800W, and the time is 30-90 minutes.
[0012] Compared with the prior art, the present invention has the following beneficial effects: 1. Significantly improves cooling rate: By introducing a small amount of highly thermally conductive filler, a "thermal highway" is constructed, enabling the phase change material to quickly transfer internal heat to the surface during the exothermic phase, and the cooling time can be shortened by 30%-70% compared to pure phase change materials.
[0013] 2. Maintain core performance: Due to the optimized addition of high thermal conductivity filler, its dilution effect on the latent heat of phase change of phase change material is minimized, and the heat storage capacity of the material (i.e. heat preservation time) is basically unaffected, achieving a balance between "rapid cooling" and "long-term heat preservation".
[0014] 3. Synergistic effect: When using a mixture of sheet graphene and spherical metal powder as filler, fillers of different dimensions can overlap to form a more complete and dense three-dimensional heat conduction network, which is more effective than a single filler.
[0015] 4. Simple process and controllable cost: The preparation method involves only melting, stirring, and ultrasonic dispersion, all of which are conventional chemical operations and are easy to scale up for industrial production. The selected fillers (such as graphite powder and aluminum powder) are low in cost and have high market value. Attached Figure Description
[0016] Figure 1 A comparison of the cooling curves of the composite phase change material provided by this invention and a comparative example (pure phase change material); Figure 2 This is a schematic diagram of the microstructure of the high thermal conductivity filler forming a thermally conductive network in the composite phase change material of the present invention. Detailed Implementation
[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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.
[0018] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.
[0019] like Figure 1 , Figure 2 As shown, a rapid cooling composite phase change material is composed of a matrix phase change material and a high thermal conductivity filler.
[0020] The matrix phase change material is a material that undergoes a solid-liquid phase change within the target phase change temperature range, and can be selected from one or more mixtures of paraffin, lauric acid, and n-octadecane. For example, the target phase change temperature can be any temperature point or range between 25°C and 60°C.
[0021] The high thermal conductivity filler is a metal powder and / or carbon material with a high thermal conductivity. Wherein: The metal powder can be selected from one or more of copper powder, aluminum powder, silver powder, and nickel powder. Its morphology can be spherical, flake-shaped, or dendritic, and the particle size range is preferably 1μm to 100μm.
[0022] The carbon material can be selected from one or more of graphene, expanded graphite, carbon nanotubes, and graphite powder.
[0023] The high thermal conductivity filler is present in the composite phase change material at a mass percentage of 0.5% to 10%. A preferred range is 1% to 5%.
[0024] Within this formulation range, the high thermal conductivity filler can form an effective thermal conductivity network in the matrix phase change material, significantly improving the overall thermal conductivity of the material and thus accelerating the cooling process. Simultaneously, due to the relatively low addition amount, it has minimal impact on the latent heat of phase change of the matrix phase change material, ensuring that the material still possesses excellent heat storage and insulation capabilities.
[0025] A method for preparing a rapidly cooling composite phase change material includes the following steps: Step 1: Pretreatment: The matrix phase change material is heated and melted into a liquid state at 60℃~80℃; the high thermal conductivity filler is vacuum dried at 80℃~100℃ for 2-4 hours to remove moisture; Step 2: Mixing: The dried high thermal conductivity filler is slowly added to the liquid matrix phase change material in batches, and mechanical stirring is carried out continuously under constant temperature conditions; Step 3: Dispersion: While stirring, ultrasonic treatment (power 300W - 800W, time 30~90 minutes) is applied to ensure that the high thermal conductivity filler is uniformly dispersed in the liquid phase and to prevent agglomeration. Step 4: Molding: Inject the uniformly mixed slurry into the mold, allow it to cool naturally or under programmed temperature control to room temperature, and solidify to obtain the rapid cooling composite phase change material.
[0026] Example 1 A rapid cooling composite phase change material is disclosed. The matrix phase change material is paraffin wax, the target phase change temperature is 42℃, and the high thermal conductivity filler is spherical copper powder.
[0027] A method for preparing a rapidly cooling composite phase change material includes the following steps: Step 1: Take 100g of paraffin wax with a phase transition temperature of 42℃ as the matrix material and heat it to melt in a 70℃ water bath; take 3g of spherical copper powder with a particle size of 20μm and vacuum dry it at 90℃ for 3 hours. Step 2: Add the dried copper powder to the molten paraffin in three batches, while mechanically stirring at 400 rpm at 70°C. Step 3: While stirring, place the mixture in an ultrasonic cell disruptor and ultrasonically disperse it for 60 minutes at a power of 500W.
[0028] Step 4: Pour the uniformly mixed slurry into a cylindrical aluminum mold, allow it to cool naturally to room temperature, and demold to obtain the copper powder / paraffin composite phase change material.
[0029] Example 2 A rapid cooling composite phase change material is disclosed. The matrix phase change material is lauric acid, the target phase change temperature is 65℃, and the high thermal conductivity filler is graphene.
[0030] A method for preparing a rapidly cooling composite phase change material includes the following steps: Step 1: Take 100g of lauric acid as the matrix material and melt it at 65℃; take 1.5g of graphene nanosheets and vacuum dry them at 80℃ for 2 hours; Step 2: Add the dried graphene to lauric acid in batches while mechanically stirring at 400 rpm at 70°C. Step 3: Mechanically stir and then sonicate at 600W power for 90 minutes.
[0031] Step 4: Inject the uniformly mixed slurry into a cylindrical aluminum mold, allow it to cool naturally to room temperature, and demold to obtain the graphene / lauric acid composite phase change material.
[0032] Example 3 A rapid cooling composite phase change material is disclosed. The matrix phase change material is n-octadecane, the target phase change temperature is 58℃, and the high thermal conductivity filler is expanded graphite and aluminum powder.
[0033] A method for preparing a rapidly cooling composite phase change material includes the following steps: Step 1: Take 100 grams of n-octadecane with a phase transition temperature of 58℃; take 1 gram of flake aluminum powder and 2 grams of expanded graphite as mixed fillers, dry them and add them together to the molten n-octadecane.
[0034] Step 2: Add the dried expanded graphite and aluminum powder to n-octadecane in batches, while mechanically stirring at 350 rpm at 70°C. Step 3: Mechanically stir and then sonicate at 400W power for 75 minutes; Step 4: Inject into the mold, cool down to 25°C and cure to obtain the mixed filler / n-octadecane composite phase change material.
[0035] Comparative Example Pure phase change materials: Take the same mass of pure paraffin, pure lauric acid, and pure octadecane as in the examples, without adding any fillers, melt them directly, and then inject them into a mold for cooling, as a benchmark for performance comparison.
[0036] Effect verification The thermal conductivity of the samples in each embodiment and comparative example was measured using a thermal constant analyzer (such as the TPS method). The samples were heated on a constant temperature hot stage until completely melted, then moved to room temperature, and the change curve of their center temperature over time was recorded using thermocouples.
[0037] Expected results: Thermal conductivity: The thermal conductivity of all sample examples was significantly higher than that of the corresponding comparative sample.
[0038] like Figure 1 As shown in the figure, the horizontal axis represents time, and the vertical axis represents temperature. It can be anticipated that the curve of this invention will drop more steeply from the high-temperature starting point, indicating a faster cooling rate. Under the same conditions, the time required for the temperature of the example sample to drop from the liquid phase to the solid phase starting point is much shorter than that of the comparative sample, demonstrating its rapid cooling characteristic. Simultaneously, in the phase transition plateau region, the holding times of the examples and the comparative examples are essentially equivalent, demonstrating that their heat preservation ability is maintained.
[0039] in addition, Figure 2 This demonstrates how highly thermally conductive fillers (such as sheet and granular fillers) can come into contact with each other in a matrix phase change material to form a continuous heat transfer path.
[0040] Example 4 A rapid cooling composite phase change material, wherein the matrix phase change material is paraffin wax, the target phase change temperature is 42℃, and the high thermal conductivity filler is spherical silver powder.
[0041] A method for preparing a rapidly cooling composite phase change material includes the following steps: Step 1: Take 100g of paraffin wax with a phase transition temperature of 42℃ as the matrix material and heat it to melt in a water bath at 75℃; take 2.5g of spherical silver powder with a particle size of 15μm and vacuum dry it at 85℃ for 2.5 hours. Step 2: Add the dried silver powder to the molten paraffin in three batches, while mechanically stirring at 450 rpm at 70°C. Step 3: While stirring, place the mixture in an ultrasonic cell disruptor and ultrasonically disperse it for 50 minutes at a power of 550W. Step 4: Pour the uniformly mixed slurry into a cylindrical aluminum mold, allow it to cool naturally to room temperature, and demold to obtain the silver powder / paraffin composite phase change material.
[0042] Example 5 A rapid cooling composite phase change material, wherein the matrix phase change material is lauric acid, the target phase change temperature is 65℃, and the high thermal conductivity filler is nickel powder.
[0043] A method for preparing a rapidly cooling composite phase change material includes the following steps: Step 1: Take 100g of lauric acid as the matrix material and melt it at 70℃; take 4g of spherical nickel powder with a particle size of 30μm and vacuum dry it at 100℃ for 3 hours; Step 2: Add the dried nickel powder to the molten lauric acid in four batches, while mechanically stirring at 380 rpm at 65°C. Step 3: Mechanically stir and then sonicate at 500W power for 80 minutes; Step 4: Pour the uniformly mixed slurry into a cylindrical aluminum mold, allow it to cool naturally to room temperature, and demold to obtain the nickel powder / lauric acid composite phase change material.
[0044] Example 6 A rapid cooling composite phase change material, wherein the matrix phase change material is n-octadecane, the target phase change temperature is 58℃, and the high thermal conductivity filler is flake graphite powder.
[0045] A method for preparing a rapidly cooling composite phase change material includes the following steps: Step 1: Take 100g of n-octadecane with a phase transition temperature of 58℃ and melt it in a water bath at 60℃; take 3.5g of flake graphite powder with a particle size of 50μm and vacuum dry it at 90℃ for 2 hours. Step 2: Add the dried graphite powder to the molten n-octadecane in three portions, while mechanically stirring at 420 rpm at 65°C. Step 3: Mechanically stir and then sonicate at 450W power for 70 minutes; Step 4: Inject the uniformly mixed slurry into a cylindrical aluminum mold, cool it down to 25°C to solidify, demold, and obtain the graphite powder / n-octadecane composite phase change material.
[0046] Example 7 A rapid-cooling composite phase change material, wherein the matrix phase change material is a mixture of n-octadecane and paraffin, or a mixture of paraffin and lauric acid, or a mixture of lauric acid and n-octadecane. The high thermal conductivity filler is flake graphite powder.
[0047] The advantages of this invention are: 1. Significantly improves cooling rate: By introducing a small amount of highly thermally conductive filler, a "thermal highway" is constructed, enabling the phase change material to quickly transfer internal heat to the surface during the exothermic phase, and the cooling time can be shortened by 30%-70% compared to pure phase change materials.
[0048] 2. Maintain core performance: Due to the optimized addition of high thermal conductivity filler, its dilution effect on the latent heat of phase change of phase change material is minimized, and the heat storage capacity of the material (i.e. heat preservation time) is basically unaffected, achieving a balance between "rapid cooling" and "long-term heat preservation".
[0049] 3. Synergistic effect: When using a mixture of sheet graphene and spherical metal powder as filler, fillers of different dimensions can overlap to form a more complete and dense three-dimensional heat conduction network, which is more effective than a single filler.
[0050] 4. Simple process and controllable cost: The preparation method involves only melting, stirring, and ultrasonic dispersion, all of which are conventional chemical operations and are easy to scale up for industrial production. The selected fillers (such as graphite powder and aluminum powder) are low in cost and have high market value.
[0051] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several changes and improvements without departing from the overall concept of the present invention, and these should also be considered within the scope of protection of the present invention.
Claims
1. A rapidly cooling composite phase change material, characterized in that: It is composed of a matrix phase change material and a high thermal conductivity filler; The matrix phase change material is a material that undergoes a solid-liquid phase change within the target phase change temperature range, and is selected from one or more mixtures of paraffin, lauric acid, and n-octadecane. The target phase change temperature is any temperature point or range between 25°C and 60°C. The high thermal conductivity filler is a metal powder and / or carbon material with a high thermal conductivity. The metal powder is selected from one or more of copper powder, aluminum powder, silver powder, and nickel powder; The carbon material can be selected from one or more of graphene, expanded graphite, carbon nanotubes, and graphite powder; The high thermal conductivity filler is present in the composite phase change material at a mass percentage of 0.5% to 10%.
2. The rapid cooling composite phase change material according to claim 1, characterized in that: The metal powder is in the form of spheres, flakes or dendrites, and the particle size range is preferably 1μm to 100μm.
3. The rapid cooling composite phase change material according to claim 1, characterized in that: The high thermal conductivity filler has a mass percentage of 1% to 5% in the composite phase change material.
4. A method for preparing a rapidly cooling composite phase change material, characterized in that: Includes the following steps: Step 1: Pretreatment: The matrix phase change material is heated and melted into a liquid state at 60℃~80℃; the high thermal conductivity filler is vacuum dried at 80℃~100℃ for 2-4 hours; Step 2: Mixing: The dried high thermal conductivity filler is slowly added to the liquid matrix phase change material in batches, and mechanical stirring is carried out continuously under constant temperature conditions; Step 3: Dispersion: While stirring, ultrasonic treatment is applied to ensure that the high thermal conductivity filler is uniformly dispersed in the liquid phase and to prevent agglomeration. Step 4: Molding: Inject the uniformly mixed slurry into the mold, allow it to cool naturally or under programmed temperature control to room temperature, and solidify to obtain the rapid cooling composite phase change material.
5. The method for preparing a rapidly cooling composite phase change material according to claim 4, characterized in that: The ultrasonic treatment power is 300W-800W, and the time is 30-90 minutes.