Polymer material enhanced fluorocoolant and method of making same
By coating the surface of polyethylene glycol phase change material with inorganic materials to form polymer phase change microcapsules, the problems of low heat dissipation efficiency of fluorine coolant and leakage of phase change material are solved, achieving a highly efficient thermal management effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- FUJIAN INST OF RES ON THE STRUCTURE OF MATTER CHINESE ACAD OF SCI
- Filing Date
- 2026-02-04
- Publication Date
- 2026-06-09
AI Technical Summary
Existing fluorinated coolants have low heat dissipation efficiency when faced with instantaneous high heat flux density impacts. Leakage of polyethylene glycol phase change materials and poor interfacial compatibility result in poor thermal conductivity.
By coating the surface of polyethylene glycol phase change material with inorganic materials to form polymer phase change microcapsules, and then mixing them with fluorine coolant, the mechanical strength and thermal conductivity of the material are enhanced.
It improves the latent heat performance and thermal conductivity of fluorine coolant, ensuring long-term stability and heat dissipation efficiency, and is suitable for thermal management of electronic equipment.
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Abstract
Description
Technical Field
[0001] This application relates to a polymer-reinforced fluorine coolant and its preparation method, belonging to the field of heat dissipation for electronic devices. Background Technology
[0002] With the increasing integration and compactness of temperature-sensitive devices such as electronic equipment, lithium-ion batteries, and photovoltaic modules, a robust thermal management system is crucial for improving equipment performance and extending lifespan. Excessively high operating temperatures degrade the performance of electronic components, lithium-ion batteries, and photovoltaic cells, necessitating a sophisticated thermal management system to mitigate this. While traditional fluorocarbon coolants (such as fluorinated polyethers and fluorinated olefins) possess excellent insulation and chemical stability, they primarily rely on sensible heat (temperature rise) to absorb heat, resulting in a relatively low specific heat capacity. Consequently, when faced with sudden surges in heat flux, the liquid temperature rises rapidly, leading to decreased heat dissipation efficiency.
[0003] Phase change materials (PCMs) undergo a phase transition at specific temperatures, storing or releasing a large amount of latent heat within a constant temperature range, which is highly effective in suppressing temperature rise. Polyethylene glycol (PEG) is a non-toxic organic solid-liquid PCM with high latent heat. Its good biocompatibility and adjustable phase transition temperature and enthalpy make it more suitable for applications in thermal management, wearable devices, and other fields compared to other organic PCMs. However, the leakage caused by PEG's solid-liquid phase transition and its low thermal conductivity limit its practical application. Microencapsulated PCM energy storage materials (also known as phase change microcapsules) encapsulate PCMs using specific encapsulation techniques to prevent leakage. Higher mechanical strength, thermal stability, and thermal conductivity can be achieved by modifying the shell material. On the other hand, the inorganic material coated on the PEG surface has poor interfacial compatibility with fluorinated coolants, resulting in unstable dispersion, high interfacial thermal resistance, and reduced thermal conductivity of the coolant. Summary of the Invention
[0004] The purpose of this invention is to overcome the defects of existing polymer phase change material fluorinated coolants, such as leakage, low thermal conductivity, and poor interfacial compatibility between phase change material and fluorinated coolant, and to provide a fluorinated coolant containing polymer phase change microcapsules.
[0005] According to a first aspect of this application, a polymer-reinforced fluorine coolant is provided.
[0006] A polymer-reinforced fluorine coolant, comprising a fluorine coolant and polymer phase change microcapsules, in weight percentages of: Fluorine coolant: 90% ~ 99%; Polymer phase change microcapsules: 1% ~ 10%.
[0007] Optionally, the polymer phase change microcapsule consists of a core material and a surface coating layer; The core material comprises a polymer phase change material; The surface coating layer is applied to the surface of the core material.
[0008] Optionally, the surface coating layer is silicon dioxide.
[0009] Optionally, the thickness of the surface coating layer is 0.01 μm to 1 μm.
[0010] Optionally, the polymer phase change microcapsules are surface modified.
[0011] Optionally, the surface modification is performed using a fluorinated silane coupling agent.
[0012] Optionally, the fluorinated silane coupling agent is selected from at least one of vinyltrifluorosilane, (3,3,3-trifluoropropyl)triethoxysilane, (3,3,3-trifluoropropyl)trimethoxysilane, 3,3,3-trifluoropropyltrichlorosilane, tridecafluorooctyltriethoxysilane, fluorinated aromatic silane, and perfluorooctyltrimethoxysilane.
[0013] Optionally, the polymer phase change material is selected from at least one of polyethylene glycol, polyethylene, cross-linked polyolefin, cross-linked polyacetal, cellulose graft copolymer, and polyester graft copolymer.
[0014] Optionally, the molecular weight of the polymer is concentrated in the range of 400 to 10,000, preferably 2,000 to 4,000.
[0015] Preferably, the polymer phase change material is selected from polyethylene glycol.
[0016] Optionally, the core material further includes thermally conductive filler; The thermally conductive filler is selected from at least one of graphene, boron nitride, aluminum oxide, and aluminum nitride.
[0017] Optionally, the graphene comprises graphene nanosheets.
[0018] Optionally, the fluorinated coolant is selected from at least one of fluorinated polyethers and fluorinated olefins.
[0019] Optionally, the fluorinated polyether is a perfluorinated polyether with a kinematic viscosity of 10 to 100 mPa·s at 40°C. The fluorinated olefin is selected from at least one of R-1234yf (2,3,3,3-tetrafluoropropylene), R-1234ze (including E and Z isomers), and R-513A, and has a kinematic viscosity of 10 to 100 mPa·s at 40°C.
[0020] Optionally, the average particle size of the polymer phase change microcapsules is 0.1 μm to 10 μm, preferably 1 μm to 5 μm.
[0021] According to a second aspect of this application, a method for preparing a polymer-reinforced fluorinated coolant is provided.
[0022] The preparation method of the fluorinated coolant of the polymer material described above includes: S1. A mixture containing polymer phase change material, precursor, alkali, and solvent is stirred and reacted to obtain the polymer phase change microcapsules. S2. Mix the polymer phase change microcapsules with a fluorine coolant to obtain a fluorine coolant for the polymer material.
[0023] Optionally, in step S1, the precursor is an orthosilicate.
[0024] Optionally, the orthosilicate is selected from at least one of methyl orthosilicate, ethyl orthosilicate, propyl orthosilicate, and butyl orthosilicate.
[0025] Preferably, the orthosilicate is selected from ethyl orthosilicate.
[0026] Optionally, the alkali is selected from ammonia.
[0027] Optionally, the reaction is carried out at room temperature for 12 to 48 hours.
[0028] Optionally, the mixture may also include thermally conductive fillers.
[0029] Optionally, the method further includes a step of surface modification of the polymer phase change microcapsules obtained in step S1: A mixture containing polymer phase change microcapsules, a fluorosilane coupling agent, and a solvent is adjusted to acidity, stirred, and reacted to obtain surface-modified polymer phase change microcapsules.
[0030] Optionally, the reaction is carried out at room temperature for 1 to 30 hours.
[0031] Optionally, the reaction is carried out at room temperature for 1 to 12 hours.
[0032] The beneficial effects that this application can produce include: (1) By reinforcing the fluorine coolant with polymer phase change materials, the latent heat performance of the fluorine coolant is improved, and the temperature of the equipment is reduced.
[0033] (2) By preparing an inorganic surface coating layer in situ on the surface of the polymer phase change material, polymer phase change microcapsules are prepared, which improves the leakage of the polymer phase change material in the solid-liquid phase change process and ensures the long-term stability of the coolant.
[0034] (3) The thermal conductivity of polymer phase change microcapsules and coolant is enhanced by using thermally conductive fillers with high thermal conductivity to reduce the temperature of the application equipment.
[0035] The coolant provided in this application is suitable for immersion liquid cooling and spray liquid cooling of data center servers, power electronic devices, new energy storage, semiconductors and other equipment. Detailed Implementation
[0036] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.
[0037] Unless otherwise specified, all raw materials used in the embodiments of this application were purchased through commercial channels.
[0038] Unless otherwise specified, all test methods are standard and all instrument settings are those recommended by the manufacturer.
[0039] Polyethylene glycol was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., perfluoropolyether coolant (PFPE) was purchased from 3M, and graphene nanosheets were purchased from Xiamen Kaina Graphene Technology Co., Ltd.
[0040] Example 1 Preparation of PEG microcapsules: 1 g polyethylene glycol (PEG-4000, molecular weight 4000), 150 mL ethanol, 40 mL water, 6 mL ammonia, and 10 mL tetraethyl orthosilicate (TEOS) were stirred and reacted for 24 h. After centrifugation and drying, SiO2 was coated on the PEG surface to prepare PEG microcapsules; the thickness of the coating layer was 0.1 μm.
[0041] Surface modification: 1 g of PEG microcapsules, 150 mL of ethanol, 40 mL of water, and 0.05 g of perfluorooctyltrimethoxysilane (FAS-17) were added, and acetic acid was added to adjust the pH to acidic 4.00. The mixture was stirred and reacted for 24 h to prepare surface-modified PEG microcapsules. The average particle size of the surface-modified PEG microcapsules was 1 μm.
[0042] Preparation of fluorinated coolant: 2 g of surface-modified PEG microcapsules and 98 g of perfluoropolyether coolant (PFPE) were mixed to prepare a fluorinated coolant. The kinematic viscosity of the perfluoropolyether coolant (PFPE) at 40 °C was 20 mPa·s.
[0043] Example 2 Replace 2g of surface-modified PEG microcapsules and 98g of perfluoropolyether coolant (PFPE) with 1g of surface-modified PEG microcapsules and 99g of perfluoropolyether coolant (PFPE), otherwise remain the same as in Example 1.
[0044] Example 3 Replace 2g of surface-modified PEG microcapsules and 98g of perfluoropolyether coolant (PFPE) with 4g of surface-modified PEG microcapsules and 96g of perfluoropolyether coolant (PFPE), otherwise remain the same as in Example 1.
[0045] Example 4 Replace 2g of surface-modified PEG microcapsules and 98g of perfluoropolyether coolant (PFPE) with 6g of surface-modified PEG microcapsules and 94g of perfluoropolyether coolant (PFPE), otherwise remain the same as in Example 1.
[0046] Example 5 Replace 2g of surface-modified PEG microcapsules and 98g of perfluoropolyether coolant (PFPE) with 8g of surface-modified PEG microcapsules and 92g of perfluoropolyether coolant (PFPE), otherwise remain the same as in Example 1.
[0047] Example 6 Replace 2g of surface-modified PEG microcapsules and 98g of perfluoropolyether coolant (PFPE) with 10g of surface-modified PEG microcapsules and 90g of perfluoropolyether coolant (PFPE), otherwise remain the same as in Example 1.
[0048] Example 7 Preparation of PEG microcapsules: 1g polyethylene glycol (PEG-4000, molecular weight 4000), 1g boron nitride, 150 mL ethanol, 40 mL water, 6 mL ammonia, and 10 mL tetraethyl orthosilicate (TEOS) were stirred and reacted for 24 h. After centrifugation and drying, SiO2 was coated on the surface of PEG to prepare PEG microcapsules; the thickness of the coating layer was 0.1 μm.
[0049] Surface modification: 1 g of PEG microcapsules, 150 mL of ethanol, 40 mL of water, and 0.05 g of perfluorooctyltrimethoxysilane (FAS-17) were added, and acetic acid was added to adjust the pH to acidic 4.00. The mixture was stirred and reacted for 24 h to prepare surface-modified PEG microcapsules. The average particle size of the surface-modified PEG microcapsules was 1 μm.
[0050] Preparation of fluorinated coolant: 2 g of surface-modified PEG microcapsules and 98 g of perfluoropolyether coolant (PFPE) were mixed to prepare a fluorinated coolant. No significant sedimentation was observed after standing in the fluorinated coolant for 72 hours.
[0051] Example 8 Replace 1g of boron nitride with 1g of aluminum nitride, otherwise remain the same as in Example 7.
[0052] Example 9 Replace 1g of boron nitride with 1g of graphene nanosheets, otherwise remain the same as in Example 7.
[0053] Example 10 Replace 1g of boron nitride with 1g of aluminum oxide, otherwise remain the same as in Example 7.
[0054] Example 11 The perfluoropolyether coolant (PFPE) was replaced with R-1234yf (2,3,3,3-tetrafluoropropylene), with a kinematic viscosity of 20 mPa·s at 40°C, otherwise the same as in Example 7.
[0055] Example 12 The perfluoropolyether coolant (PFPE) was replaced with R-1234ze(E), with a kinematic viscosity of 60 mPa·s at 40°C, otherwise the same as in Example 7.
[0056] Example 13 The perfluoropolyether coolant (PFPE) was replaced with R-513A, with a kinematic viscosity of 60 mPa·s at 40°C, otherwise the same as in Example 7.
[0057] Example 14 Replace perfluorooctyltrimethoxysilane (FAS-17) with vinyltrifluorosilane, otherwise remain the same as in Example 7.
[0058] Example 15 Replace polyethylene glycol (PEG-4000, molecular weight 4000) with polyethylene glycol (PEG-6000, molecular weight 6000), otherwise it is the same as in Example 7.
[0059] Example 16 Replace polyethylene glycol (PEG-4000, molecular weight 4000) with polyethylene glycol (PEG-2000, molecular weight 2000), otherwise it is the same as in Example 7.
[0060] Example 17 Preparation of PEG microcapsules: 1g polyethylene glycol (PEG-4000, molecular weight 4000), 1g boron nitride, 150 mL ethanol, 40 mL water, 6 mL ammonia, and 10 mL tetraethyl orthosilicate (TEOS) were stirred and reacted for 24 h. After centrifugation and drying, SiO2 was coated on the surface of PEG to prepare PEG microcapsules.
[0061] Preparation of fluorinated coolant: 2g of PEG microcapsules and 98g of perfluoropolyether coolant (PFPE) were mixed to prepare fluorinated coolant.
[0062] Comparative Example 1 Perfluoropolyether coolant (PFPE) without the addition of polyethylene glycol.
[0063] Comparative Example 2 2g of polyethylene glycol (PEG-4000, molecular weight 4000) was mixed with 98g of perfluoropolyether coolant (PFPE) to prepare fluorinated coolant.
[0064] Comparative Example 3 2g of polyethylene glycol (PEG-400, molecular weight 400) was mixed with 98g of perfluoropolyether coolant (PFPE) to prepare fluorinated coolant.
[0065] Application examples The fluorine coolants of Examples 1-17 and Comparative Examples 1-3 were applied to immersion liquid-cooled servers in computing centers.
[0066] Performance testing: The thermal conductivity of the coolant was tested using a thermal conductivity meter or a laser flare meter; the viscosity of the coolant was tested using a viscometer; the temperature was cycled multiple times, and the shape change of the phase change capsule was observed to test the cycle stability; the temperature of the computing center server and energy storage products was monitored using a temperature sensor, and the phase change temperature and latent heat were tested using a DSC differential scanning calorimeter.
[0067]
[0068] Examples 1-17: Polymer phase change microcapsules enhanced fluorine coolants, compared to Comparative Examples 1-3, exhibit improved thermal conductivity and cycle stability. When applied to immersion liquid-cooled servers in data centers, the server's maximum temperature significantly decreased. Example 1: Compared to Comparative Example 1, the addition of polymer phase change microcapsules to the fluorine coolant improved the coolant's thermal conductivity and cycle stability, resulting in a decrease in the equipment's maximum temperature. Example 17: Compared to Comparative Example 2, preparing polymer phase change materials into microcapsules improved cycle stability and reduced the equipment's maximum temperature. Example 7: Compared to Example 17, surface modification of PEG microcapsules improved the coolant's thermal conductivity and cycle stability, leading to a decrease in the equipment's maximum temperature. Example 7: Compared to Example 1, the addition of thermally conductive materials to the phase change microcapsules further improved the coolant's thermal conductivity. When applied to immersion liquid-cooled servers in data centers, the server's maximum temperature further decreased.
[0069] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.
Claims
1. A polymer-reinforced fluorinated coolant, characterized in that, Includes fluorine coolant and polymer phase change microcapsules, by weight percentage: Fluorine coolant: 90% ~ 99%; Polymer phase change microcapsules: 1% ~ 10%.
2. The fluorinated coolant for polymer materials according to claim 1, characterized in that, The polymer phase change microcapsules consist of a core material and a surface coating layer; The core material comprises a polymer phase change material; The surface coating layer is applied to the surface of the core material; Preferably, the surface coating layer is silicon dioxide; Preferably, the thickness of the surface coating layer is 0.01 μm to 1 μm.
3. The fluorinated coolant for polymer materials according to claim 1, characterized in that, The polymer phase change microcapsules are surface modified; Preferably, the surface modification is performed using a fluorinated silane coupling agent; Preferably, the fluorinated silane coupling agent is selected from at least one of vinyltrifluorosilane, (3,3,3-trifluoropropyl)triethoxysilane, (3,3,3-trifluoropropyl)trimethoxysilane, 3,3,3-trifluoropropyltrichlorosilane, tridecafluorooctyltriethoxysilane, fluorinated aromatic silane, and perfluorooctyltrimethoxysilane.
4. The fluorinated coolant for polymer materials according to claim 2, characterized in that, The polymer phase change material is selected from at least one of polyethylene glycol, polyethylene, cross-linked polyolefin, cross-linked polyacetal, cellulose graft copolymer, and polyester graft copolymer; Preferably, the molecular weight of the polymer is concentrated in the range of 400 to 10,000, and more preferably in the range of 2,000 to 4,000.
5. The fluorinated coolant for polymer materials according to claim 2, characterized in that, The core material also contains thermally conductive filler; The thermally conductive filler is selected from at least one of graphene, boron nitride, aluminum oxide, and aluminum nitride.
6. The fluorinated coolant for polymer materials according to claim 1, characterized in that, The fluorinated coolant is selected from at least one of fluorinated polyethers and fluorinated olefins; Preferably, the fluorinated polyether is a perfluorinated polyether with a kinematic viscosity of 10-100 mPa·s at 40°C. The fluorinated olefin is selected from at least one of R-1234yf, R-1234ze, and R-513A, and has a kinematic viscosity of 10 to 100 mPa·s at 40°C.
7. The fluorinated coolant for polymer materials according to claim 1, characterized in that, The average particle size of the polymer phase change microcapsules is 0.1 μm to 10 μm, preferably 1 μm to 5 μm.
8. A method for preparing a fluorinated coolant from a polymer material according to any one of claims 1 to 7, characterized in that, The preparation method includes: S1. A mixture containing polymer phase change material, precursor, alkali, and solvent is stirred and reacted to obtain the polymer phase change microcapsules. S2. Mix the polymer phase change microcapsules with a fluorine coolant to obtain a fluorine coolant for the polymer material.
9. The preparation method according to claim 8, characterized in that, In step S1, the precursor is an orthosilicate; Preferably, the orthosilicate is selected from at least one of methyl orthosilicate, ethyl orthosilicate, propyl orthosilicate, and butyl orthosilicate; Preferably, the alkali is selected from ammonia water; Preferably, the reaction is carried out at room temperature for 12-48 hours; Preferably, the mixture further includes a thermally conductive filler.
10. The preparation method according to claim 8, characterized in that, It also includes a step of surface modification of the polymer phase change microcapsules obtained in step S1: A mixture containing polymer phase change microcapsules, a fluorosilane coupling agent, and a solvent is adjusted to acidity, stirred, and reacted to obtain surface-modified polymer phase change microcapsules. Preferably, the reaction is carried out at room temperature for 1 to 30 hours.