Macrocyclic compound / aluminum oxide nano-composite heat conduction agent particle, preparation method thereof and macromolecule-based electronic cooling liquid

Abstract

The macrocyclic compound / aluminum oxide nano-composite heat-conducting agent particle is prepared according to the following method: adding a macrocyclic compound, aluminum oxide and potassium carbonate into a ball-milling tank, grinding, pausing heat dissipation at intervals in the grinding process, and after the grinding is finished, obtaining the macrocyclic compound / aluminum oxide nano-composite heat-conducting agent particle. And carrying out ultrasonic extraction by using a mixed solution of dichloromethane and water to obtain a product, wherein the macrocyclic compounds are pillar [5] arene, beta-cyclodextrin and calix [4] arene. The product provided by the invention has the advantages of excellent heat-conducting property, high surface tension, high specific heat capacity, high heat conductivity, high resistivity, environmental friendliness, low toxicity, strong compatibility and controllable cost.

Description

Technical Field

[0002] This invention relates to the field of electronic coolant technology, specifically to a macrocyclic compound / alumina nanocomposite thermal conductive particle, its preparation method, and a polymer-based electronic coolant. Background Technology

[0004] With the rapid development of microelectronics technology towards high power density and miniaturization, and the technological iteration in fields such as new energy vehicles and intelligent industrial manufacturing, the heat density generated during equipment operation has significantly increased. Efficient thermal management has become a core requirement for ensuring equipment reliability and extending its service life. As a key heat transfer medium in the thermal management system, the thermal conductivity of coolant directly determines heat dissipation efficiency. The thermal conductivity of traditional organic coolants (such as ethylene glycol aqueous solutions and mineral oils) is typically only 0.1-0.6 W / m·K, which is insufficient to meet the heat dissipation requirements of high heat flux density scenarios.

[0005] To improve the thermal conductivity of coolants, adding high thermal conductivity fillers to the base fluid to prepare composite coolants is currently the mainstream technical approach. Alumina (Al2O3) is a commonly used inorganic thermally conductive filler due to its excellent thermal conductivity (high-purity dense Al2O3 can reach 30-35 W / m·K at room temperature), good electrical insulation, high chemical stability, and low cost. However, Al2O3 has two major drawbacks in practical applications: First, Al2O3 has a strong surface polarity, resulting in poor compatibility with non-polar or weakly polar organic base fluids, easily leading to agglomeration and preventing the formation of a continuous thermally conductive network, thus limiting the improvement of thermal conductivity. Second, to achieve ideal thermal conductivity, a high amount of Al2O3 needs to be added, but a high filling amount significantly increases the viscosity of the coolant, deteriorates its flow properties, increases pumping energy consumption, and may also exacerbate pipe wear, affecting system operational stability.

[0006] In existing technologies, researchers often use silane coupling agents and polydopamine to modify the surface of Al2O3 to improve its compatibility with the base liquid. For example, patent document CN117624833A describes a reaction between Al2O3 and nanodiamonds (NDs) with silane coupling agents and anhydrous ethanol to obtain a mixture of Al2O3@PDA@NDs with good thermal conductivity. However, these modifiers only alleviate agglomeration problems and cannot further improve thermal conductivity. Furthermore, some modifiers suffer from insufficient thermal stability and poor environmental friendliness. In addition, while liquid metal thermal conductive media possess extremely high thermal conductivity—for example, patent document CN110643331 describes a liquid metal thermal paste prepared using one or more metal powders such as copper powder, silver powder, and aluminum powder with a viscosity modifier—it suffers from drawbacks such as easy leakage, strong interfacial corrosion, and compatibility issues with most metal materials (e.g., causing liquid metal embrittlement)—making its widespread application difficult. Summary of the Invention

[0008] To address the aforementioned technical problems, the present invention aims to provide a method for preparing macrocyclic compound / alumina nanocomposite thermal conductive particles, a second objective is to provide the macrocyclic compound / alumina nanocomposite thermal conductive particles thus prepared, and a third objective is to provide a polymer-based electronic coolant. The macrocyclic compound / alumina nanocomposite thermal conductive particles exhibit good compatibility with the base liquid and possess excellent thermal conductivity, high surface tension, high specific heat capacity, high thermal conductivity, high resistivity, environmental friendliness, and low toxicity.

[0009] To achieve the above objectives, the present invention is implemented through the following technical solution: a method for preparing macrocyclic compound / alumina nanocomposite thermal conductive particles, characterized in that it is prepared by the following method: adding macrocyclic compound, alumina and potassium carbonate into a ball mill jar, grinding, pausing heat dissipation during the grinding process, and after grinding, ultrasonically extracting the product with a mixed solution of dichloromethane and water, wherein the macrocyclic compound is columnar[5] aromatics, β-cyclodextrin and calix[4] aromatics.

[0010] In the above scheme, the molar ratio of the macrocyclic compound, aluminum oxide and potassium carbonate is 1: 1.2-2.0: 2.0-3.0.

[0011] In the above scheme, the grinding time is 30-60 minutes.

[0012] In the above scheme: pause for 3-5 minutes to dissipate heat after every 8-10 minutes of grinding.

[0013] In the above scheme: the volume ratio of dichloromethane to water is 1:1. After extraction, the organic phases are combined, dried with anhydrous sodium sulfate, the solvent is removed by vacuum distillation, the product is collected by silica gel column chromatography, the eluent is removed by distillation, and the product is dried to obtain the product.

[0014] In the above scheme: the eluent used for silica gel column chromatography is dichloromethane and n-hexane in a volume ratio of 1:1.

[0015] The macrocyclic compound / alumina nanocomposite thermal conductive particles are prepared by a method described above.

[0016] Macrocyclic compounds (columnar[5]arenes, β-cyclodextrins and calix[4]arenes) are organic compounds with cyclic cavity structures. The cavity size can be precisely matched to specific ions or molecules, and different polar groups can be introduced into the molecular surface through functionalization modification. Based on their unique cavity recognition ability and structural tunability, macrocyclic compounds have shown excellent performance in molecular recognition, catalysis, and material surface modification. The modification principle of this invention is as follows:

[0017] (1) Surface modification and dispersion stabilization mechanism of macrocyclic compounds: Macrocyclic compound molecules bind to the surface of nano-Al2O3 particles through two interaction mechanisms: On the one hand, the oxygen, nitrogen and other heteroatoms in the macrocyclic compound molecules can bind to the Al2O3 surface. 3+ Coordination bonds are formed, achieving strong adsorption at the molecular level. Furthermore, the cyclic cavities of the macrocyclic compound can encapsulate the active sites on the surface of nano-Al2O3 particles through van der Waals forces and hydrophobic interactions. Through this modification, the macrocyclic compound forms an organic coating layer on the surface of Al2O3 particles, significantly reducing the van der Waals attraction between nano-Al2O3 particles. Simultaneously, it matches the surface polarity of the Al2O3 particles with the polarity of the base coolant (perfluoropolyether), effectively inhibiting particle aggregation and achieving uniform dispersion of Al2O3 in the base liquid, laying the foundation for constructing a continuous heat-conducting network.

[0018] (2) Balancing mechanism between low viscosity and high thermal conductivity: Due to the surface modification effect of macrocyclic compounds, uniform dispersion of Al2O3 and construction of a continuous thermally conductive network can be achieved with low filling amount, so as to achieve excellent thermal conductivity without adding high dose of nano-Al2O3 particles, thereby effectively controlling the viscosity of coolant. In addition, the flexible structure of macrocyclic compound molecules can form a lubricating layer on the surface of composite particles, reducing the frictional resistance of composite particles during flow, further optimizing the flow performance of coolant and reducing system pumping energy consumption.

[0019] The third objective of this invention is to provide a polymer-based electronic coolant characterized by containing macrocyclic compound / alumina nanocomposite thermal conductive particles as described in claim 7.

[0020] The above scheme is composed of the following raw materials in parts by weight: 83-91 parts of perfluoropolyether (PFPE), 2-5 parts of macrocyclic compound / Al2O3 nanocomposite thermal conductive particles, 3-6 parts of methyl ethyl ether, 4-6 parts of phosphate ester flame retardant, 0.1-0.2 parts of butylated hydroxytoluene, and 0.05-0.15 parts of fluorocarbon surfactant.

[0021] Compared with the prior art, the coolant of the present invention has the following beneficial effects:

[0022] (1) Excellent thermal conductivity: When the amount of macrocyclic compound / alumina nanocomposite thermal conductive agent particles added is small, the thermal conductivity of the coolant can reach 0.113~0.132 W / m·K, which is 73.8~103.1% higher than that of commercially available coolants.

[0023] (2) High surface tension, high specific heat capacity, high thermal conductivity, and high resistivity

[0024] The system has high surface tension, good stability and anti-interference ability; high resistivity and good insulation performance; specific heat capacity of 1.531~1.683 J / (g·℃) and thermal conductivity of 0.113~0.132 W / m·K, which is significantly improved compared with the thermal conductivity of similar commercially available products.

[0025] (3) Environmental friendliness and low toxicity

[0026] The coolant of this invention uses macrocyclic compound / Al2O3 nanocomposite material as a heat conductor, which poses no environmental safety risks, is non-toxic, has extremely low volatility, and ensures material compatibility.

[0027] (4) Strong compatibility

[0028] Composite thermal conductive agents have high chemical stability, do not react with pipeline materials, and have good electrical insulation properties, making them suitable for applications such as electronic equipment where insulation is required.

[0029] (5) Cost controllable

[0030] The alumina and macrocyclic compounds used are all commercially available raw materials, and the preparation process of the nanocomposite thermal conductive agent is simple and easy to scale up. Detailed Implementation

[0032] The present invention will be further described below with reference to embodiments.

[0033] Example 1

[0034] Preparation method of macrocyclic compound / alumina nanocomposite thermal conductive particles: 1 mol of macrocyclic compound columnarene [5], 1.2 mol of alumina and 2.0 mol of potassium carbonate were added to a ball mill jar and ground for 30 min. During the grinding process, the grinding was paused for 5 min to dissipate heat every 10 min. After grinding, the product was extracted by ultrasonic extraction with a mixed solution of dichloromethane and water (volume ratio 1:1). The extraction was performed three times, and the organic phases were combined (water and dichloromethane were separated into layers, and the water layer was removed). The product was dried with anhydrous sodium sulfate, and the solvent was removed by vacuum distillation to obtain crude product. The product was collected by silica gel column chromatography. The eluent used for silica gel column chromatography was dichloromethane and n-hexane in a volume ratio of 1:1. The eluent was removed by vacuum distillation and dried to obtain macrocyclic compound / alumina nanocomposite thermal conductive particles.

[0035] The polymer-based electronic coolant is composed of the following raw materials in parts by weight: 83 parts perfluoropolyether (PFPE), 3 parts macrocyclic compound / Al2O3 nanocomposite thermal conductive particles, 3 parts methyl ethyl ether, 4 parts phosphate ester flame retardant, 0.1 parts butylated hydroxytoluene, and 0.1 parts fluorocarbon surfactant. It is obtained by ultrasonic dispersion for 30 minutes.

[0036] Example 2

[0037] Preparation method of macrocyclic compound / alumina nanocomposite thermal conductive particles: 1 mol of macrocyclic compound β-cyclodextrin (β-CD), 2 mol of aluminum oxide and 3 mol of potassium carbonate were added to a ball mill jar and ground for 48 min. During the grinding process, the grinding was paused for 3 min every 8 min to dissipate heat. After grinding, the product was extracted by ultrasonic extraction with a mixed solution of dichloromethane and water (volume ratio 1:1). The extraction was performed three times, the organic phases were combined, dried with anhydrous sodium sulfate, and the solvent was removed by vacuum distillation to obtain crude product. The product was collected by silica gel column chromatography. The eluent used for silica gel column chromatography was dichloromethane and n-hexane (volume ratio 1:1). The eluent was removed by vacuum distillation and dried to obtain macrocyclic compound / alumina nanocomposite thermal conductive particles.

[0038] The polymer-based electronic coolant is composed of the following raw materials in parts by weight: 91 parts perfluoropolyether (PFPE), 5 parts macrocyclic compound / Al2O3 nanocomposite thermal conductive particles, 6 parts methyl ethyl ether, 6 parts phosphate ester flame retardant, 0.2 parts butylated hydroxytoluene, and 0.15 parts fluorocarbon surfactant. It is obtained by ultrasonic dispersion for 30 minutes.

[0039] Example 3

[0040] Preparation method of macrocyclic compound / alumina nanocomposite thermal conductive particles: 1 mol of macrocyclic compound calix[4]arene, 1.5 mol of alumina and 2.5 mol of potassium carbonate were added to a ball mill jar and ground for 60 min. During the grinding process, the grinding was paused for 4 min to dissipate heat every 10 min. After grinding, the product was extracted by ultrasonic extraction with a mixed solution of dichloromethane and water (volume ratio 1:1). The extraction was repeated three times, the organic phases were combined, dried with anhydrous sodium sulfate, and the solvent was removed by vacuum distillation to obtain crude product. The product was collected by silica gel column chromatography. The eluent used for silica gel column chromatography was dichloromethane and n-hexane in a volume ratio of 1:1. The eluent was removed by vacuum distillation and dried to obtain macrocyclic compound / alumina nanocomposite thermal conductive particles.

[0041] The polymer-based electronic coolant is composed of the following raw materials in parts by weight: 83 parts perfluoropolyether (PFPE), 2 parts macrocyclic compound / Al2O3 nanocomposite thermal conductive particles, 4 parts methyl ethyl ether, 4 parts phosphate ester flame retardant, 0.1 parts butylated hydroxytoluene, and 0.05 parts fluorocarbon surfactant. It is obtained by ultrasonic dispersion for 30 minutes.

[0042] Table 1. Performance Comparison Study of the Product of this Invention with Similar Products

[0043]

[0044] As can be seen from Table 1, the system of the present invention has a large surface tension, good stability and anti-interference ability; high resistivity and good insulation performance; specific heat capacity of 1.531~1.683 J / (g·℃) and thermal conductivity of 0.113~0.132 W / m·K, which is significantly improved compared with similar products.

[0045] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing macrocyclic compound / alumina nanocomposite thermal conductive particles, characterized in that, The product was prepared as follows: macrocyclic compounds, aluminum oxide and potassium carbonate were added to a ball mill jar and ground. During the grinding process, heat dissipation was paused intermittently. After grinding, the product was extracted by ultrasonic extraction with a mixed solution of dichloromethane and water. The macrocyclic compounds were columnar[5] aromatics, β-cyclodextrin and calix[4] aromatics.

2. The method for preparing macrocyclic compound / alumina nanocomposite thermal conductive particles according to claim 1, characterized in that: The molar ratio of the macrocyclic compound, aluminum oxide, and potassium carbonate is 1: 1.2-2.0: 2.0-3.

0.

3. The method for preparing macrocyclic compound / alumina nanocomposite thermal conductive particles according to claim 1 or 2, characterized in that: Grinding time: 30-60 minutes.

4. The method for preparing macrocyclic compound / alumina nanocomposite thermal conductive particles according to claim 3, characterized in that: Pause for 3-5 minutes to cool down after every 8-10 minutes of grinding.

5. The method for preparing macrocyclic compound / alumina nanocomposite thermal conductive particles according to claim 4, characterized in that: The volume ratio of dichloromethane to water was 1:

1. After extraction, the organic phases were combined, dried with anhydrous sodium sulfate, the solvent was removed by vacuum distillation, the product was collected by silica gel column chromatography, the eluent was removed by distillation, and the product was dried to obtain the final product.

6. The method for preparing macrocyclic compound / alumina nanocomposite thermal conductive particles according to claim 5, characterized in that: The eluent used in silica gel column chromatography was dichloromethane and n-hexane in a volume ratio of 1:

1.

7. Macrocyclic compound / alumina nanocomposite thermal conductive particles prepared by the method of any one of claims 1-6.

8. A polymer-based electronic coolant, characterized in that: It contains macrocyclic compound / alumina nanocomposite thermal conductive particles as described in claim 7.

9. The polymer-based electronic coolant according to claim 8, characterized in that: It is composed of the following raw materials in parts by weight: 83-91 parts of perfluoropolyether (PFPE), 2-5 parts of macrocyclic compound / Al2O3 nanocomposite thermal conductive particles, 3-6 parts of methyl ethyl ether, 4-6 parts of phosphate ester flame retardant, 0.1-0.2 parts of butylated hydroxytoluene, and 0.05-0.15 parts of fluorocarbon surfactant.

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