A method for enhancing heat transfer at the interface of a metallic material and an organic material

Abstract

This invention discloses a method for enhancing heat transfer at the interface between metallic and organic materials, belonging to the field of enhanced heat transfer. The method involves using an electro-acoustic coupling material at the metal / organic interface as a bridge connecting electron and phonon heat conduction. Electron heat conduction dominates between the metallic material and the electro-acoustic coupling material, while phonon heat conduction dominates between the organic material and the electro-acoustic coupling material. This enhances the electron-phonon interface heat transport, achieving enhanced heat transfer at the metal / organic interface. This method contributes to improving the heat transfer performance of metal / organic interfaces and enhancing the performance of thermal interface materials, nanofluids, and solid-liquid phase change materials.

Description

Technical Field

[0001] This invention relates to the field of enhanced heat transfer, specifically to a method for enhancing heat transfer at the interface between metallic and organic materials. Background Technology

[0002] Metal / organic interface heat transfer is widely used in energy generation, conversion, and transmission. Thermal interface materials are based on organic materials, with high thermal conductivity fillers added to increase their thermal conductivity and fill gaps. Metal micro / nanoparticles are a commonly used high thermal conductivity filler. However, the formation of numerous interfaces between metal micro / nanoparticles and organic materials limits the improvement in thermal conductivity of these interface materials despite the large amount of metal doping. Nanofluids involve adding high thermal conductivity particles to organic liquids such as water or oil to improve the fluid's thermal conductivity. However, metal micro / nanoparticles exhibit significant interfacial thermal resistance when in contact with organic liquids. Solid-liquid phase change materials (SCTs) are media for solid-liquid phase change heat storage. Due to the low thermal conductivity of phase changes, metal fins or metal particles are typically added inside the SCT to increase its thermal conductivity. The large number of metal / organic interfaces increases the temperature difference between the heat source and the SCT, reducing the efficiency of thermal energy storage. In summary, these interfacial heat transfer bottlenecks ultimately lead to reduced material and device reliability. Therefore, improving interfacial heat transport is a key technological challenge in many cutting-edge technology fields.

[0003] Especially for metal / organic interfaces, from a microscopic thermal conductivity perspective, metals are dominated by electron thermal conductivity, while thermal grease is dominated by phonon thermal conductivity. These different energy transfer mechanisms result in significant interfacial thermal resistance. To enhance heat transfer at metal / organic interfaces, methods that strengthen interfacial phonon transport are commonly employed, involving the insertion of an intermediate material at the interface to increase phonon density of states matching and enhance interfacial bonding strength. However, this method only addresses the phonon aspect, while the primary heat carrier within metals is the electron, thus limiting its effectiveness in enhancing interfacial heat transfer. Therefore, strengthening electron-phonon interfacial thermal transport is crucial for improving heat transfer at metal / organic interfaces. Summary of the Invention

[0004] To enhance heat transfer at the metal / organic interface, this invention provides a method for strengthening heat transfer at the interface between metal and organic materials. The method involves using an electroacoustic coupling material at the metal / organic interface as a bridge connecting electron and phonon heat conduction. Electron heat conduction dominates between the metal and the electroacoustic coupling material, while phonon heat conduction dominates between the organic and the electroacoustic coupling material. This enhances heat transport at the electron-phonon interface, thereby achieving enhanced heat transfer at the metal / organic interface.

[0005] The present invention first provides a method for enhancing heat transfer at the interface between metal and organic materials, comprising the following steps: introducing a layer of electroacoustic coupling material at the interface between the metal and organic materials.

[0006] In the above method, the metallic material and the organic material are connected in a planar manner; or,

[0007] The metallic material is dispersed in an organic material matrix.

[0008] The electroacoustic coupling material is a material whose conductivity is between that of metallic and organic materials, including conductive polymers, ionic liquids, or liquid metals.

[0009] The conductive polymer is a material with a conjugated main electron system as its main chain, which can achieve a conductive state through doping; specifically, it can be polyacetylene, polythiophene, polypyrrole, polyaniline, polyphenylene, polyphenylene ethylene, or polydiacetylene.

[0010] The ionic liquid is composed of cations and anions; the cations are quaternary ammonium salt ions, quaternary phosphorus salt ions, or imidazole salt ions; the anions are halide ions, tetrafluoroborate ions, or hexafluorophosphate ions; more specifically, they may be 1-ethyl-3-methylimidazolium hexafluorophosphate.

[0011] The liquid metal is a pure metal or alloy with a melting point at room temperature; specifically, it can be gallium, gallium indium, gallium indium tin, gallium indium tin zinc, indium, indium tin, bismuth indium tin, or bismuth indium tin lead; more specifically, it can be a gallium indium alloy.

[0012] In the above method, the metallic material and the electroacoustic coupling material are connected by metallic bonds, covalent bonds, or van der Waals forces;

[0013] The electroacoustic coupling material and the organic material are connected by covalent bonds, hydrogen bonds, or van der Waals forces.

[0014] In the above method, the connection method between the metal material and the electroacoustic coupling material is immersion, spin coating, magnetron sputtering, high-temperature corrosion or electroplating;

[0015] The connection method between the electroacoustic coupling material and the organic material is immersion, spin coating, magnetron sputtering, high-temperature corrosion, or electroplating.

[0016] In the above method, the metal material is one of pure metals such as aluminum, copper, iron, and nickel, and their alloys; specifically, it can be copper.

[0017] The organic material is a high molecular polymer or silicone oil, etc.; specifically, it can be polydimethylsiloxane.

[0018] The present invention also provides a composite material comprising a metallic material, an electroacoustic coupling material, and an organic material connected in sequence.

[0019] In the aforementioned composite material, the metallic material and the organic material are connected in a planar manner; or,

[0020] The metallic material is dispersed in an organic material matrix.

[0021] The electroacoustic coupling material is a material whose conductivity is between that of metallic and organic materials, including conductive polymers, ionic liquids, or liquid metals.

[0022] Specifically, the conductive polymer is a material whose main chain has a conjugated main electron system and can achieve a conductive state through doping; more specifically, it can be polyacetylene, polythiophene, polypyrrole, polyaniline, polyphenylene, polyphenylene ethylene, or polydiacetylene.

[0023] Specifically, the ionic liquid is composed of cations and anions; the cations are quaternary ammonium salt ions, quaternary phosphonium salt ions, or imidazole salt ions; the anions are halide ions, tetrafluoroborate ions, or hexafluorophosphate ions; more specifically, they may be 1-ethyl-3-methylimidazolium hexafluorophosphate.

[0024] The liquid metal is a pure metal or alloy with a melting point at room temperature; more specifically, it may be gallium, gallium indium, gallium indium tin, gallium indium tin zinc, indium, indium tin, bismuth indium tin, or bismuth indium tin lead.

[0025] In the aforementioned composite material, the metallic material and the electroacoustic coupling material are connected by metallic bonds, covalent bonds, or van der Waals forces;

[0026] The electroacoustic coupling material and the organic material are connected by covalent bonds, hydrogen bonds or van der Waals forces;

[0027] Specifically, the connection method between the metal material and the electroacoustic coupling material can be immersion, spin coating, magnetron sputtering, high-temperature corrosion, or electroplating;

[0028] The connection method between the electroacoustic coupling material and the organic material can be immersion, spin coating, magnetron sputtering, high-temperature corrosion, or electroplating.

[0029] The aforementioned composite material, wherein the metal material is one of pure metals such as aluminum, copper, iron, and nickel, or their alloys; specifically, it may be copper.

[0030] The organic material is a high molecular polymer or silicone oil, etc.; specifically, it can be polydimethylsiloxane.

[0031] The method of this invention involves using an electroacoustic coupling material at a metal / organic interface as a bridge connecting electron and phonon thermal conduction. The metal material and the electroacoustic coupling material primarily conduct heat electronically, while the organic material and the electroacoustic coupling material primarily conduct heat phonon-basedly. This method helps enhance the heat transfer performance of the metal / organic interface and improves the performance of thermal interface materials, nanofluids, and solid-liquid phase change materials. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of the present invention; in the figure, 1 is a metallic material, 2 is an electroacoustic coupling material, and 3 is an organic material.

[0033] Figure 2 This is a schematic diagram of Embodiment 2 of the structure of the present invention; in the figure, 1 is a metallic material, 2 is an electroacoustic coupling material, and 3 is an organic material. Detailed Implementation

[0034] The present invention will be further described in detail below with reference to specific embodiments. The embodiments given are only for illustrating the present invention and are not intended to limit the scope of the present invention.

[0035] Unless otherwise specified, the experimental methods described in the following examples are conventional methods.

[0036] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.

[0037] The gallium-indium alloy used in the following examples is a eutectic alloy of metallic gallium and metallic indium with a melting point of 15 degrees Celsius. First, weigh 75.5% gallium and 24.5% indium (by mass), place them in a crucible, heat at 100°C for 2 hours, remove and stir for 2 minutes to obtain the gallium-indium alloy.

[0038] Polydimethylsiloxane was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0039] 1-Ethyl-3-methylimidazolium hexafluorophosphate was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0040] The method of this invention involves attaching a layer of electroacoustic coupling material to a metal surface, and then attaching an organic material to the surface of the electroacoustic coupling material to form a sandwich structure. The principle is that the metal material and the electroacoustic coupling material primarily conduct heat electronically, while the organic material and the electroacoustic coupling material primarily conduct heat phononically. The electroacoustic coupling material thus bridges the gap between electronic and phonon heat conduction.

[0041] Example 1

[0042] like Figure 1 As shown, a sandwich structure material is provided, which is in the form of a flat plate and includes a metal material 1, an electroacoustic coupling material 2 and an organic material 3; the electroacoustic coupling material 2 is located between the metal material 1 and the organic material 3.

[0043] The electroacoustic coupling material 3 is liquid gallium metal.

[0044] The metal material 1 can be pure metals such as copper, iron, and nickel, or their alloys;

[0045] The organic material 3 can be a polymer, silicone oil, etc.

[0046] The metal material 1 and the electroacoustic coupling material 2 are connected by metallic bonds or van der Waals forces. Specifically, the metal material 1 can be immersed in the electroacoustic coupling material 2 and then placed in a high-temperature furnace for 10 minutes to form metallic bonds at the interface between the two. Alternatively, the electroacoustic coupling material 2 can be spin-coated onto the surface of the metal material 1 to connect the two in the form of van der Waals forces.

[0047] The organic material 3 is connected to the electroacoustic coupling material 2 by covalent bonds, hydrogen bonds, or van der Waals forces. Specifically, the organic material 3 can be sulfurized to form -HS end groups, which are then connected to the electroacoustic coupling material 2 by covalent bonds. Alternatively, the organic material 3 can be treated with hydroxyl or carboxyl groups to form -OH or -COOH end groups, which are then connected to the electroacoustic coupling material 2 by hydrogen bonds. If the above functional groups are not present, the materials are connected by van der Waals forces.

[0048] For the electroacoustic coupling material 3, which is a three-layer structure of liquid gallium metal, electrons carry most of the energy inside the metal material 1 and transfer it to the interface between the metal material 1 and the electroacoustic coupling material 2. Then, electrons cross the interface and transfer to the interior of the electroacoustic coupling material 2, where electroacoustic coupling occurs and some of the energy is transferred to phonons. Then, at the interface between the electroacoustic coupling material 2 and the organic material 3, the two materials mainly conduct heat through phonons, transferring energy to the organic material 3, thereby achieving enhanced heat transfer at the metal / organic interface.

[0049] Example 2

[0050] like Figure 2 As shown, the metallic material is dispersed in an organic material matrix, including metallic material 1, electroacoustic coupling material 2, and organic material 3. In this embodiment, the electroacoustic coupling material 2 is first attached to the surface of the metallic material 1, and then the metallic material 1 is dispersed in the organic material 3. The material selection and connection method are the same as in Embodiment 1.

[0051] Example 3

[0052] 1. Preparation of copper powder / gallium indium / polydimethylsiloxane composite material

[0053] First, at room temperature, 20g of copper powder (800 mesh) was immersed in 30mL of 1mol / L hydrochloric acid for 10 minutes to remove the surface oxide layer. Then, 110g of gallium-indium alloy was poured into the solution and stirred at room temperature for 10 minutes to coat the surface of the copper powder with a layer of liquid metal. The mixture of liquid metal and copper powder was then removed and dried to completely remove moisture. The dried mixture was then added to 21g of polydimethylsiloxane and stirred thoroughly for 10 minutes. After being placed in a vacuum drying oven and vacuumed for 30 minutes, it was heated at 120℃ for 2 hours to cure.

[0054] 2. Preparation of copper powder / polydimethylsiloxane composite material

[0055] At room temperature, 89g of copper powder (800 mesh) was soaked in 50mL of 1mol / L hydrochloric acid for 10 minutes to remove the surface oxide layer; then the copper powder was taken out and dried to completely remove moisture; then the copper powder was added to 10g of polydimethylsiloxane and stirred thoroughly for 10 minutes, placed in a vacuum drying oven and vacuumed for 30 minutes, and then heated at 120℃ for 2 hours to cure.

[0056] 3. Preparation of gallium indium / polydimethylsiloxane composite materials

[0057] Add 64g of gallium-indium alloy to 10g of polydimethylsiloxane and stir thoroughly for 10 minutes. Place in a vacuum drying oven and evacuate for 30 minutes. Then heat at 120°C for 2 hours to cure.

[0058] In the copper powder / gallium indium / polydimethylsiloxane composite material, metallic material 1 is 800-mesh copper powder, electroacoustic coupling material 2 is a gallium indium alloy, and organic material 3 is polydimethylsiloxane. The thermal conductivity of these materials was measured: the thermal conductivity of the copper powder / gallium indium / polydimethylsiloxane composite material is 6.20 W / (m·K); the thermal conductivity of the copper powder / polydimethylsiloxane composite material is 0.96 W / (m·K); and the thermal conductivity of the gallium indium / polydimethylsiloxane composite material is 2.10 W / (m·K). This indicates that the gallium indium alloy, as a bonding material, is beneficial in reducing the interfacial thermal resistance between copper and polydimethylsiloxane.

[0059] Example 4

[0060] First, immerse a 5cm diameter copper plate in 1mol / L hydrochloric acid to remove the oxide layer, and dry it to remove moisture before use. Then, drop 1g of ionic liquid 1-ethyl-3-methylimidazolium hexafluorophosphate onto the surface of the copper plate and spin-coat it. Next, drop 5g of polydimethylsiloxane onto the spin-coated surface of the copper plate and spin-coat it again. Finally, place it in a vacuum drying oven at 120℃ for 2 hours to cure it.

[0061] In the composite material prepared above, the electroacoustic coupling material 2 is an ionic liquid, 1-ethyl-3-methylimidazolium hexafluorophosphate. The electroacoustic coupling material 2 is spin-coated onto the surface of the metal material 1, and the two are connected by van der Waals forces.

[0062] Example 5

[0063] First, at room temperature, 50g of copper powder is soaked in 30mL of 1mol / L hydrochloric acid for 10min to remove the surface oxide layer. Then, 5g of polypyrrole is added to the solution and stirred for 10min. The mixture of polypyrrole and copper powder is then removed and dried to remove moisture. The dried mixture is added to 10g of polydimethylsiloxane and stirred thoroughly for 10min. After being placed in a vacuum drying oven and vacuumed for 30min, it is heated at 120℃ for 2 hours to cure.

[0064] In the materials prepared above, the electroacoustic coupling material 2 is polypyrrole. The difference from Example 3 is that the chemical composition of polypyrrole is similar to that of organic material 3, and it forms a covalent bond with organic material 3.

Claims

1. A method for enhancing heat transfer at the interface between a metallic material and an organic material, comprising the following steps: introducing a layer of electroacoustic coupling material at the interface between the metallic material and the organic material; The metallic material and the organic material are connected in a planar manner; or, the metallic material is dispersed in an organic material matrix. The electroacoustic coupling material is a material whose conductivity is between that of metallic and organic materials, and it is a liquid metal. The metallic material is one of pure metals such as aluminum, copper, iron, and nickel, and their alloys; The organic material is a polymer or silicone oil; The liquid metal is gallium, gallium indium, gallium indium tin, gallium indium tin zinc, indium, indium tin, bismuth indium tin, or bismuth indium tin lead; The metallic material and the electroacoustic coupling material are connected by metallic bonds, covalent bonds, or van der Waals forces. The electroacoustic coupling material and the organic material are connected by covalent bonds, hydrogen bonds, or van der Waals forces.

2. The method according to claim 1, characterized in that: The connection method between the metallic material and the electroacoustic coupling material is immersion, spin coating, magnetron sputtering, high-temperature corrosion, or electroplating. The connection method between the electroacoustic coupling material and the organic material is immersion, spin coating, magnetron sputtering, high-temperature corrosion, or electroplating.

3. A composite material comprising a metallic material, an electroacoustic coupling material, and an organic material connected in sequence; The electroacoustic coupling material is located at the interface between the metallic and organic materials; The metallic material and the organic material are connected in a planar manner; or, the metallic material is dispersed in an organic material matrix. The electroacoustic coupling material is a material whose conductivity is between that of metallic and organic materials, and it is a liquid metal. The metallic material is one of pure metals such as aluminum, copper, iron, and nickel, and their alloys; The organic material is a polymer or silicone oil; The liquid metal is gallium, gallium indium, gallium indium tin, gallium indium tin zinc, indium, indium tin, bismuth indium tin, or bismuth indium tin lead; The metallic material and the electroacoustic coupling material are connected by metallic bonds, covalent bonds, or van der Waals forces. The electroacoustic coupling material and the organic material are connected by covalent bonds, hydrogen bonds, or van der Waals forces.

4. The composite material according to claim 3, characterized in that: The connection method between the metallic material and the electroacoustic coupling material is immersion, spin coating, magnetron sputtering, high-temperature corrosion, or electroplating. The connection method between the electroacoustic coupling material and the organic material is immersion, spin coating, magnetron sputtering, high-temperature corrosion, or electroplating.

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