CN114525113A - Method for enhancing interface heat transfer of metal material and organic material - Google Patents

Abstract

The invention discloses a method for enhancing interface heat transfer of a metal material and an organic material, belonging to the field of enhanced heat transfer. The method of the invention uses the electro-acoustic coupling material at the metal/organic interface as a bridge for connecting electron and phonon heat conduction, wherein electron heat conduction is mainly used between the metal material and the electro-acoustic coupling material, phonon heat conduction is mainly used between the organic material and the electro-acoustic coupling material, so that the heat transport of the electron-phonon interface is enhanced, and the enhanced heat transfer of the metal/organic interface is realized. The method is beneficial to enhancing the heat transfer performance of the metal/organic interface and improving the performance of a thermal interface material, a nano fluid and a solid-liquid phase change material.

Description

A method for strengthening the interface heat transfer between metal materials and organic materials

technical field

The invention relates to the field of strengthening heat transfer, in particular to a method for strengthening the interface heat transfer between a metal material and an organic material.

Background technique

Heat transfer at metal/organic interfaces is widely used in the fields of energy generation, transformation and transmission. Thermal interface materials are based on organic materials, and their thermal conductivity is increased by adding high thermal conductivity fillers to fill gaps, and metal micro-nano particles are one of the commonly used high thermal conductivity fillers. A large number of interfaces are formed between metal micro-nano particles and organic materials, resulting in the limitation that a large number of metal particles are doped and the thermal conductivity of thermal interface materials is limited. Nanofluid is the addition of high thermal conductivity particles to organic liquids such as water or oil to increase the thermal conductivity of the fluid. Metal micro-nano particles have great interfacial thermal resistance when they are in contact with organic liquids. The solid-liquid phase change material is a medium for solid-liquid phase change heat storage. Since the thermal conductivity of the phase change is small, the thermal conductivity is generally increased by constructing metal fins or adding metal particles inside the phase change material. The large number of metal/organic interfaces increases the temperature difference between the heat source and the phase change material, reducing the efficiency of thermal energy storage. Taken together, these interfacial heat transfer bottlenecks ultimately lead to reduced material and device reliability. Therefore, enhancing interfacial thermal transport is a technical challenge facing many frontier technological fields.

Especially for the metal/organic interface, from the perspective of the microscopic thermal conduction mechanism, the metal is dominated by the electronic thermal conductivity, and the thermal conductive silicone grease is dominated by the phonon thermal conductivity. The energy transfer mechanism of the two is different, resulting in a huge interface thermal resistance. In order to enhance the heat transfer at the metal/organic interface, the method of enhancing the interface phonon transmission is usually adopted, and a layer of intermediate material is inserted at the interface to increase the phonon density of states matching and enhance the interface bonding strength. However, this method is only from the point of view of phonons, and the main heat carriers inside the metal are electrons, so the effect of enhancing heat transfer at the interface is limited. How to enhance the thermal transport at the electron-phonon interface is the key to the enhanced heat transfer at the metal/organic interface.

SUMMARY OF THE INVENTION

In order to strengthen the heat transfer at the metal/organic interface, the present invention provides a method for strengthening the heat transfer at the interface between a metal material and an organic material. The method of the invention is to use the electro-acoustic coupling material at the metal/organic interface as a bridge connecting electrons and phonons for heat conduction, wherein the electronic heat conduction is mainly between the metal material and the electro-acoustic coupling material, and the organic material is coupled with the electro-acoustic coupling. The phonon heat conduction between materials is mainly used to strengthen the heat transport at the electron-phonon interface and realize the enhanced heat transfer at the metal/organic interface.

The present invention first provides a method for enhancing heat transfer at the interface between a metal material and an organic material, comprising the following steps: introducing a layer of electro-acoustic coupling material at the interface between the metal material and the organic material.

In the above-mentioned method, the metal material is connected with the organic material in a planar form; or,

The metallic material is dispersed in an organic material matrix.

The electro-acoustic coupling material is a material whose electrical conductivity is between metal materials and organic materials, including conductive polymers, ionic liquids or liquid metals.

The conductive polymer has a conjugated main electron system in the main chain, and can achieve a conductive state through doping; specifically, it can be polyacetylene, polythiophene, polypyrrole, polyaniline, polyphenylene, polyphenylene vinylene or poly Diacetylene;

The ionic liquid is composed of a cation and an anion; the cation is a quaternary ammonium salt ion, a quaternary phosphonium salt ion or an imidazolium salt ion; the anion is a halide ion, a tetrafluoroborate ion or a hexafluorophosphate ion; It is 1-ethyl-3-methylimidazole hexafluorophosphate.

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 gallium Indium alloy.

In the above method, the metal material and the electro-acoustic coupling material are connected by a metal bond, a covalent bond or a van der Waals force;

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

In the above method, the connection method of the metal material and the electro-acoustic coupling material is immersion, spin coating, magnetron sputtering, high temperature corrosion or electroplating;

The connection method of the electro-acoustic coupling material and the organic material is soaking, spin coating, magnetron sputtering, high temperature corrosion or electroplating.

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

The organic material is high molecular polymer or silicone oil, etc.; specifically, polydimethylsiloxane.

The present invention also provides a composite material, which includes a metal material, an electro-acoustic coupling material and an organic material which are connected in sequence.

The above composite material, the metal material and the organic material are connected in a plane form; or,

The metallic material is dispersed in an organic material matrix.

The electro-acoustic coupling material is a material whose electrical conductivity is between metal materials and organic materials, including conductive polymers, ionic liquids or liquid metals.

Specifically, the conductive polymer has a conjugated main electron system in the main chain, and can achieve a conductive state by doping; more specifically, it can be polyacetylene, polythiophene, polypyrrole, polyaniline, polyphenylene, polyphenylene vinylene or polydiacetylene;

Specifically, the ionic liquid is composed of a cation and an anion; the cation is a quaternary ammonium salt ion, a quaternary phosphonium salt ion or an imidazolium salt ion; the anion is a halide ion, a tetrafluoroborate ion or a hexafluorophosphate ion; More specifically, it may be 1-ethyl-3-methylimidazolium hexafluorophosphate.

The liquid metal is a pure metal or alloy with a melting point at room temperature; more 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.

In the above-mentioned composite material, the metal material and the electro-acoustic coupling material are connected by metal bond, covalent bond or van der Waals force;

The electroacoustic coupling material and the organic material are connected by covalent bond, hydrogen bond or van der Waals force;

Specifically, the connection method of the metal material and the electro-acoustic coupling material may be immersion, spin coating, magnetron sputtering, high temperature corrosion or electroplating;

The connection method of the electroacoustic coupling material and the organic material may be immersion, spin coating, magnetron sputtering, high temperature etching or electroplating.

In the above composite material, the metal material is one of pure metals such as aluminum, copper, iron, nickel and their alloys; specifically, copper.

The organic material is high molecular polymer or silicone oil, etc.; specifically, polydimethylsiloxane.

The method of the invention is to use the electro-acoustic coupling material at the metal/organic interface as a bridge connecting electrons and phonons for heat conduction, wherein the electronic heat conduction is mainly between the metal material and the electro-acoustic coupling material, and the organic material is coupled with the electro-acoustic coupling. Phonons are the main heat conduction between materials; the method of the invention helps to 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.

Description of drawings

Figure 1 is a schematic diagram of the structure of the present invention; in the figure, 1 is a metal material, 2 is an electro-acoustic coupling material, and 3 is an organic material.

FIG. 2 is a schematic diagram of Embodiment 2 of the structure of the present invention; in the figure, 1 is a metal material, 2 is an electro-acoustic coupling material, and 3 is an organic material.

Detailed ways

The present invention will be further described in detail below with reference to the specific embodiments, and the given examples are only for illustrating the present invention, rather than for limiting the scope of the present invention.

The experimental methods in the following examples are conventional methods unless otherwise specified.

The materials, reagents, etc. used in the following examples can be obtained from commercial sources unless otherwise specified.

The gallium-indium alloy used in the following examples is a eutectic alloy of metal gallium and metal indium, and the melting point is 15 degrees Celsius. First, 75.5% gallium and 24.5% indium (by mass) were weighed, placed in a crucible, heated at 100° C. for 2 hours, taken out and stirred for 2 minutes to obtain a gallium-indium alloy.

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

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

The method of the invention is to attach a layer of electro-acoustic coupling material on the metal surface, and then attach organic material to the surface of the electro-acoustic coupling material to form a sandwich structure. The principle is that electronic heat conduction is the main between metal materials and electro-acoustic coupling materials, and phonon heat conduction is the main between organic materials and electro-acoustic coupling materials. A bridge connecting electronic heat conduction and phonon heat conduction is built through electro-acoustic coupling materials. .

Example 1

As shown in FIG. 1, a sandwich structure material is provided, which is in the form of a flat plate, including a metal material 1, an electro-acoustic coupling material 2 and an organic material 3; the electro-acoustic coupling material 2 is in the metal material 1 and the organic material 3. Material 3 middle.

Wherein, the electro-acoustic coupling material 3 is liquid metal gallium.

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

The organic material 3 can be high molecular polymer, silicone oil, etc.;

The metal material 1 is connected with the electro-acoustic coupling material 2 by metal bonds or van der Waals force; specifically, the metal material 1 can be immersed in the electro-acoustic coupling material 2 and then placed in a high-temperature furnace for 10 minutes, so that the two A metal bond is formed at the interface of the metal material 1; the electro-acoustic coupling material 2 can also be spin-coated on the surface of the metal material 1, so that the two are connected in the form of van der Waals force.

The organic material 3 is connected with the electro-acoustic coupling material 2 by covalent bonds, hydrogen bonds or van der Waals force; specifically, the organic material 3 can be subjected to vulcanization to form a -HS end group, which can be shared with the electro-acoustic coupling material 2 in a common manner. They are connected in the form of valence bonds; the organic material 3 can also be treated with hydroxyl or carboxyl groups to form -OH, -COOH end groups, which are connected with the electroacoustic coupling material 2 in the form of hydrogen bonds; if there is no such functional group, it is connected in the form of van der Waals force. .

For the three-layer structure in which the electro-acoustic coupling material 3 is liquid metal gallium, inside the metal material 1, electrons carry most of the energy and transfer to the interface of the metal material 1/electro-acoustic coupling material 2; then the electrons pass through the interface to the electro-acoustic coupling Inside material 2, electro-acoustic coupling occurs inside, and part of the energy is transferred to phonons; then at the interface of electro-acoustic coupling material 2/organic material 3, the two materials conduct heat conduction mainly through phonons, transferring energy to organic materials. material 3, thereby achieving enhanced heat transfer at the metal/organic interface.

Example 2

As shown in FIG. 2 , the metallic material is dispersed in the organic material matrix, including metallic material 1 , electro-acoustic coupling material 2 and organic material 3 . In this embodiment, the electro-acoustic coupling material 2 is first attached to the surface of the metal material 1 , and then the metal material 1 is dispersed in the organic material 3 . The material selection and connection method are the same as those in the first embodiment.

Example 3

1. Preparation of copper powder/gallium indium/polydimethylsiloxane composites

First, immerse 20g copper powder (800 mesh) in 30mL, 1mol/L hydrochloric acid for 10 minutes at room temperature to remove the surface oxide layer; then, pour 110g gallium indium alloy into the solution, stir at room temperature for 10 minutes to make A layer of liquid metal was plated on the surface of the copper powder; then the mixture of the liquid metal and the copper powder was taken out and dried to completely remove the moisture; the dried mixture was added to 21 g of polydimethylsiloxane, stirred thoroughly for 10 minutes, and placed After evacuating in a vacuum drying oven for 30 minutes, it was heated at 120° C. for 2 hours for curing.

2. Preparation of copper powder/polydimethylsiloxane composites

At room temperature, soak 89g copper powder (800 mesh) in 50mL, 1mol/L hydrochloric acid for 10 minutes to remove the surface oxide layer; then take out the copper powder and dry it to completely remove the moisture; then add the copper powder to 10g polydimethyl The siloxane was fully stirred for 10 minutes, placed in a vacuum drying oven and evacuated for 30 minutes, and then heated at 120° C. for 2 hours for curing.

3. Preparation of gallium indium/polydimethylsiloxane composites

Add 64 g of gallium indium alloy to 10 g of polydimethylsiloxane, stir well for 10 minutes, place it in a vacuum drying box and vacuumize for 30 minutes, then heat at 120° C. for 2 hours for curing.

In the copper powder/gallium indium/polydimethylsiloxane composite material, the metal material 1 is 800 mesh copper powder, the electroacoustic coupling material 2 is a gallium indium alloy, and the organic material 3 is polydimethylsiloxane. The thermal conductivity of the above materials was measured, and the thermal conductivity of the copper powder/gallium indium/polydimethylsiloxane composite material was 6.20 W/(m·K). The thermal conductivity of copper powder/polydimethylsiloxane composite material is 0.96W/(m·K); the thermal conductivity of gallium indium/polydimethylsiloxane composite material is 2.10W/(m·K) ). It can be seen from the above that the gallium indium alloy as a bonding material is beneficial to reduce the interface thermal resistance between copper and polydimethylsiloxane.

Example 4

First, a copper plate with a diameter of 5 cm was immersed in 1 mol/L hydrochloric acid to remove the oxide layer, dried to remove water for use; then, 1 g of the ionic liquid 1-ethyl-3-methylimidazolium hexafluorophosphate was dropped on the surface of the copper plate and rotated Then, 5g of polydimethylsiloxane was dropped on the surface of the spin-coated copper plate, spin-coated, and finally placed in a vacuum drying oven at 120° C. for 2 hours for curing.

In the composite material prepared above, the electroacoustic coupling material 2 is the ionic liquid 1-ethyl-3-methylimidazolium hexafluorophosphate. By spin-coating the electroacoustic coupling material 2 on the surface of the metal material 1, the two are connected in the form of van der Waals force.

Example 5

First, soak 50g of copper powder in 30mL, 1mol/L hydrochloric acid for 10min at room temperature to remove the surface oxide layer; then, pour 5g of polypyrrole into the solution and stir for 10 minutes; then take out the mixture of polypyrrole and copper powder , dried to remove moisture; the dried mixture was added to 10 g of polydimethylsiloxane, fully stirred for 10 minutes, placed in a vacuum drying box and vacuumed for 30 minutes, heated at 120° C. for 2 hours for curing.

Among the above-prepared materials, the electroacoustic coupling material 2 is polypyrrole, which is different from Example 3 in that the chemical composition of polypyrrole and the organic material 3 are close, and form a covalent bond with the organic material 3 .

Claims (10)

1. A method for enhancing interface heat transfer of a metal material and an organic material comprises the following steps: introducing a layer of electro-acoustic coupling material at an interface of the metallic material and the organic material.

2. The method of claim 1, wherein: the metal material and the organic material are connected in a planar form; or the like, or, alternatively,

the metallic material is dispersed in a matrix of organic material.

3. The method according to claim 1 or 2, characterized in that: the electro-acoustic coupling material is a material with the electric conductivity between that of a metal material and that of an organic material, and comprises a conductive polymer, ionic liquid or liquid metal;

the metal material is one of pure metals of aluminum, copper, iron and nickel and alloys thereof;

the organic material is high molecular polymer or silicone oil.

4. The method of claim 3, wherein: the conductive polymer is a material with a conjugated main electron system in a main chain and can reach a conductive state through doping; specifically polyacetylene, polythiophene, polypyrrole, polyaniline, polyphenylene ethylene or polydiyne;

the ionic liquid is composed of cations and anions; the cation is quaternary ammonium salt ion, quaternary phosphonium salt ion or imidazole salt ion; the anion is halogen ion, tetrafluoroborate ion or hexafluorophosphate ion;

the liquid metal is pure metal or alloy with the melting point at room temperature; specifically, it may be gallium, gallium indium tin zinc, indium tin, bismuth indium tin, or bismuth indium tin lead.

5. The method according to any one of claims 1-4, wherein: the metal material and the electroacoustic coupling material are connected by metal bonds, covalent bonds or van der waals forces;

the electro-acoustic coupling material and the organic material are connected by covalent bonds, hydrogen bonds, or van der waals forces.

6. The method according to any one of claims 1-5, wherein: the connection method of the metal material and the electroacoustic coupling material comprises soaking, spin coating, magnetron sputtering, high-temperature corrosion or electroplating;

the connection method of the electroacoustic coupling material and the organic material comprises soaking, spin coating, magnetron sputtering, high-temperature corrosion or electroplating.

7. A composite material comprises a metal material, an electroacoustic coupling material and an organic material which are connected in sequence.

8. The composite material of claim 7, wherein: the metal material and the organic material are connected in a planar form; or the like, or, alternatively,

the metallic material is dispersed in a matrix of organic material.

9. The composite material according to claim 7 or 8, characterized in that: the electro-acoustic coupling material is a material with the electric conductivity between that of a metal material and that of an organic material, and comprises a conductive polymer, ionic liquid or liquid metal;

the metal material is one of pure metals of aluminum, copper, iron and nickel and alloys thereof;

the organic material is high molecular polymer or silicone oil;

specifically, the conductive polymer is a material with a conjugated main electron system in a main chain and can reach a conductive state through doping; more specifically polyacetylene, polythiophene, polypyrrole, polyaniline, polyphenylene ethylene or polydiyne;

specifically, the ionic liquid is composed of a cation and an anion; the cation is quaternary ammonium salt ion, quaternary phosphonium salt ion or imidazole salt ion; the anion is halogen ion, tetrafluoroborate ion or hexafluorophosphate ion;

specifically, the liquid metal is a pure metal or an alloy with a melting point at room temperature; more specifically gallium, gallium indium tin zinc, indium tin, bismuth indium tin, or bismuth indium tin lead.

10. The composite material according to any one of claims 7-9, characterized in that: the metal material and the electroacoustic coupling material are connected by metal bonds, covalent bonds or van der waals forces;

the electro-acoustic coupling material and the organic material are connected by covalent bonds, hydrogen bonds or van der waals forces;

specifically, the connection method of the metal material and the electroacoustic coupling material can be soaking, spin coating, magnetron sputtering, high-temperature corrosion or electroplating;

the connection method of the electroacoustic coupling material and the organic material can be soaking, spin coating, magnetron sputtering, high-temperature corrosion or electroplating.

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