Composition for preparing graphene nanofluid cooling liquid, graphene nanofluid cooling liquid as well as preparation method and application of graphene nanofluid cooling liquid

Abstract

The invention relates to the technical field of cooling liquid, and discloses a composition for preparing graphene nanofluid cooling liquid, the graphene nanofluid cooling liquid as well as a preparation method and application of the graphene nanofluid cooling liquid, and the composition comprises the following components in parts by weight: 60-80 parts of water; 20-40 parts by weight of ethylene glycol; 3-5 parts by weight of modified graphene; 1-3 parts by weight of spherical alumina; 0.5 to 1 part by weight of a carbon nanotube; 0.5 to 1.5 parts by weight of a corrosion inhibitor; and 0.5 to 1.2 parts by weight of fumed silica. The graphene nanofluid cooling liquid has relatively good stability, and has relatively good heat conduction performance and corrosion resistance.

Description

Technical Field

[0001] The invention relates to the technical field of coolants, and in particular to a composition for preparing a graphene nanofluid coolant, a graphene nanofluid coolant, a preparation method thereof and applications thereof. Background Art

[0002] With the rapid development of new energy vehicles, electronic equipment, data centers, servers and other fields, the demand for cooling technology is increasing at a rapid rate. These fields require equipment to be able to operate stably for a long time under high power density and high load conditions, and improper heat dissipation will lead to performance degradation or even damage to the equipment. Coolant plays a vital role in these applications. It not only effectively transfers the heat generated by the equipment, but also maintains the optimal working state of the equipment by controlling the temperature, preventing the system from overheating, thereby extending the service life of the equipment.

[0003] Traditional coolants are usually composed of water, ethylene glycol, additives and preservatives. Although they have a certain thermal conductivity effect, in the face of increasingly complex high heat flux density environments, the thermal conductivity of traditional coolants has gradually become insufficient. For example, in new energy vehicle battery packs, efficient heat dissipation is crucial to battery life and safety; while in data centers and servers, continuous high-temperature operation not only affects system efficiency, but also leads to a significant increase in energy consumption. Data center cooling usually accounts for 30% to 50% of its total energy consumption, so more efficient cooling technology is needed to reduce energy consumption and ensure long-term stable operation of equipment.

[0004] Nanofluid is a special fluid formed by nanoscale solid particles dispersed in a liquid matrix. Due to its excellent thermal conductivity and heat conduction efficiency, it is widely used in various thermal management systems.

[0005] Therefore, it is of great significance to study and develop a nanofluid coolant. Summary of the invention

[0006] The purpose of the present invention is to overcome the defects of low heat transfer efficiency and insufficient corrosion resistance of existing coolants, and to provide a composition for preparing a graphene nanofluid coolant and a graphene nanofluid coolant and a preparation method and application thereof. The graphene nanofluid coolant has good stability, good thermal conductivity and corrosion resistance.

[0007] In order to achieve the above object, the first aspect of the present invention provides a composition for preparing a graphene nanofluid coolant, wherein, by weight, the composition comprises:

[0008] Water: 60-80 parts by weight;

[0009] Ethylene glycol: 20-40 parts by weight;

[0010] Modified graphene: 3-5 parts by weight;

[0011] Spherical alumina: 1-3 parts by weight;

[0012] Carbon nanotubes: 0.5-1 parts by weight;

[0013] Corrosion inhibitor: 0.5-1.5 parts by weight;

[0014] Fumed silica: 0.5-1.2 parts by weight.

[0015] The second aspect of the present invention provides a method for preparing a graphene nanofluid coolant using the aforementioned composition, wherein the method comprises:

[0016] (1) contacting and mixing ethylene glycol, modified graphene, spherical alumina, carbon nanotubes, fumed silica and an optional dispersion stabilizer to obtain a mixed solution;

[0017] (2) homogenizing the mixed solution to obtain a homogenized solution;

[0018] (3) contacting the homogenized solution with water, an optional viscosity regulator, a corrosion inhibitor, an optional defoaming agent, and an optional antioxidant to blend and mix, and subjecting the mixture to vacuum degassing to obtain a graphene nanofluid coolant.

[0019] The third aspect of the present invention provides a graphene nanofluid coolant prepared by the method described above.

[0020] A fourth aspect of the present invention provides an application of the aforementioned graphene nanofluid coolant in one or more of new energy vehicles, electronic equipment, data centers and servers.

[0021] Through the above technical solution, the present invention has the following beneficial effects:

[0022] (1) The present invention improves the thermal conductivity of graphene nanofluid coolant by compounding spherical alumina, carbon nanotubes, fumed silica and modified graphene of different particle sizes and shapes.

[0023] (2) The modified graphene used in the present invention can form a dense corrosion inhibition layer on the metal surface, which can produce a synergistic effect with traditional corrosion inhibitors, significantly improve the corrosion resistance of metal parts, and achieve a more effective protection effect.

[0024] (3) The present invention can effectively improve the dispersibility in the system by adding graphene with surface functional modification, achieve its uniform distribution in the matrix, overcome the tendency of graphene aggregation, and improve the stability of nanoparticles in the graphene nanofluid coolant. DETAILED DESCRIPTION

[0025] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0026] As mentioned above, the first aspect of the present invention provides a composition for preparing a graphene nanofluid coolant, wherein, in parts by weight, the composition comprises:

[0027] Water: 60-80 parts by weight;

[0028] Ethylene glycol: 20-40 parts by weight;

[0029] Modified graphene: 3-5 parts by weight;

[0030] Spherical alumina: 1-3 parts by weight;

[0031] Carbon nanotubes: 0.5-1 parts by weight;

[0032] Corrosion inhibitor: 0.5-1.5 parts by weight;

[0033] Fumed silica: 0.5-1.2 parts by weight.

[0034] The inventors of the present invention have discovered that graphene is a carbon atom in the form of sp 2 The hybrid orbitals form a hexagonal honeycomb lattice planar film, a two-dimensional material with a thickness of only one carbon atom. Its low-dimensional structure can significantly reduce the boundary scattering of phonons at the grain boundaries and give it a special phonon diffusion mode. Studies have shown that the thermal conductivity of graphene at room temperature reaches 5300W / (m·k), with excellent thermal conductivity and mechanical properties.

[0035] Furthermore, the inventors of the present invention have optimized the stacking structure of the thermally conductive particles by compounding thermally conductive fillers of different particle sizes and shapes, specifically, compounding spherical alumina, carbon nanotubes, fumed silica and modified graphene, to form a tighter three-dimensional thermally conductive network. This structure helps to improve the effective establishment of thermal conductive pathways, thereby enhancing the thermal conductivity of the graphene nanofluid coolant.

[0036] Furthermore, the modified graphene used in the present invention has a unique structure and can form a dense corrosion inhibition layer on the metal surface, synergistically acting with traditional corrosion inhibitors to construct a multi-level protective barrier. This composite protection system significantly improves the corrosion resistance of metal parts and achieves a more effective protection effect.

[0037] Furthermore, by adding graphene with surface functional modifications, the dispersibility in the system can be effectively improved, its uniform distribution in the matrix can be achieved, the tendency of graphene aggregation can be overcome, and the stability of nanoparticles in the graphene nanofluid coolant can be improved.

[0038] According to the present invention, preferably, the composition for preparing the graphene nanofluid coolant comprises:

[0039] Water: 65-80 parts by weight;

[0040] Ethylene glycol: 20-35 parts by weight;

[0041] Modified graphene: 3.5-5 parts by weight;

[0042] Spherical alumina: 1.8-3 parts by weight;

[0043] Carbon nanotubes: 0.7-1 parts by weight;

[0044] Corrosion inhibitor: 0.8-1.5 parts by weight;

[0045] Fumed silica: 0.8-1.2 parts by weight.

[0046] According to the present invention, the modified graphene is selected from one or more of sulfonated graphene, amidated graphene, hydroxylated graphene and carboxylated graphene.

[0047] According to the present invention, the modified graphene is in the form of flakes, with a flake diameter of 10-20 μm and a number of layers ≤ 5. In the present invention, it should be noted that “flake diameter” refers to the lateral size of the graphene (ie, the size in the plane).

[0048] According to the present invention, the particle size of the spherical alumina is between 2-10 μm, and the specific surface area is between 150-750 m 2 / g.

[0049] According to the present invention, the diameter of the carbon nanotubes is between 5-10 nm, the length is between 50-150 μm, and the specific surface area is between 2000-5000 m 2 / g.

[0050] According to the present invention, the particle size of the fumed silica is between 5-25 nm and the specific surface area is between 100-600 m 2 / g.

[0051] According to the present invention, preferably, the composition further comprises:

[0052] Dispersion stabilizer: 0.1-1.5 parts by weight;

[0053] Viscosity modifier: 0.3-0.9 parts by weight;

[0054] Defoaming agent: 0.1-0.3 parts by weight;

[0055] Antioxidant: 0.5-1 parts by weight.

[0056] According to the present invention, more preferably, the composition further comprises:

[0057] Dispersion stabilizer: 0.8-1.5 parts by weight;

[0058] Viscosity modifier: 0.6-0.9 parts by weight;

[0059] Defoaming agent: 0.2-0.3 parts by weight;

[0060] Antioxidant: 0.6-1 parts by weight.

[0061] According to the present invention, the water is deionized water.

[0062] According to the present invention, the purity of ethylene glycol is ≥99.9%.

[0063] According to the present invention, the dispersion stabilizer is selected from one or more of polyvinyl pyrrolidone, carboxymethyl cellulose, sodium dodecylbenzene sulfonate, hydrolyzed polymaleic anhydride and phosphonic acid-based polyacrylic acid.

[0064] According to the present invention, the viscosity modifier is selected from one or more of polyethylene glycol, polyacrylamide, hydroxypropyl methylcellulose and guar gum.

[0065] According to the present invention, the corrosion inhibitor is selected from one or more of isophthalic acid, sebacic acid, 2-hydroxyphosphonoacetic acid, aminotri(methylenephosphonic acid) and cyclohexene-1,2-dicarboxylic acid.

[0066] According to the present invention, the defoaming agent is selected from one or more of polydimethylsiloxane, polyether-modified polysiloxane, polyacrylic acid, polymethacrylic acid and dodecyl alcohol polyoxyethylene ether.

[0067] According to the present invention, the antioxidant is selected from one or more of 2,6-di-tert-butylhydroquinone, butylated hydroxyanisole, dibenzothiazole disulfide, 3,5-di-tert-butyl-4-hydroxybenzoic acid and 4-hydroxy-2,6-di-tert-butylphenol.

[0068] The second aspect of the present invention provides a method for preparing a graphene nanofluid coolant using the aforementioned composition, wherein the method comprises:

[0069] (1) contacting and mixing ethylene glycol, modified graphene, spherical alumina, carbon nanotubes, fumed silica and an optional dispersion stabilizer to obtain a mixed solution;

[0070] (2) homogenizing the mixed solution to obtain a homogenized solution;

[0071] (3) contacting the homogenized solution with water, an optional viscosity regulator, a corrosion inhibitor, an optional defoaming agent, and an optional antioxidant to blend and mix, and subjecting the mixture to vacuum degassing to obtain a graphene nanofluid coolant.

[0072] According to the present invention, in order to make the prepared graphene nanofluid coolant have better stability, better thermal conductivity and better corrosion resistance, preferably, the present invention provides a method for preparing a graphene nanofluid coolant comprising:

[0073] (1) contacting and mixing ethylene glycol, modified graphene, spherical alumina, carbon nanotubes, fumed silica and a dispersion stabilizer to obtain a mixed solution;

[0074] (2) homogenizing the mixed solution to obtain a homogenized solution;

[0075] (3) contacting the homogenized solution with water, a viscosity regulator, a corrosion inhibitor, a defoaming agent and an antioxidant to blend and mix, and subjecting the mixture to vacuum degassing to obtain a graphene nanofluid coolant.

[0076] According to the present invention, in step (1), the mixing conditions include: stirring and shearing dispersion at a speed of 2500-3000 rpm for 1-3 hours to obtain a mixed solution.

[0077] According to the present invention, in step (2), the homogenization treatment conditions include: treating at a homogenization pressure of 2000-4000 bar to obtain a homogenized solution; preferably, treating at a homogenization pressure of 2000-4000 bar for 5-8 cycles to obtain a homogenized solution.

[0078] According to the present invention, in step (3), the blending and mixing conditions include: stirring at a speed of 500-800 rpm for 0.5-1 hour.

[0079] According to the present invention, in step (3), the conditions of the vacuum degassing treatment include: a vacuum degree between 0.03-0.1 MPa, and a duration of 20-60 minutes.

[0080] The third aspect of the present invention provides a graphene nanofluid coolant prepared by the method described above.

[0081] According to the present invention, the thermal conductivity of the graphene nanofluid coolant at a temperature of 25° C. is 0.38-0.85 W / m·K, preferably 0.6-0.8 W / m·K, and more preferably 0.645-0.767 W / m·K.

[0082] According to the present invention, the specific heat capacity of the graphene nanofluid coolant at a temperature of 25° C. is 3.5-7.8 J / g·K, preferably 5-7 J / g·K, preferably 5.83-6.02 J / g·K.

[0083] According to the present invention, the heat transfer corrosion of the graphene nanofluid coolant for cast aluminum alloy is 0.07-0.65 mg / cm 2 , preferably 0.1-0.3 mg / cm 2 , preferably 0.11-0.26 mg / cm 2 .

[0084] A fourth aspect of the present invention provides an application of the aforementioned graphene nanofluid coolant in one or more of new energy vehicles, electronic equipment, data centers and servers.

[0085] According to a particularly preferred embodiment of the present invention, a method for preparing a graphene nanofluid coolant comprises the following steps:

[0086] (1) firstly placing ethylene glycol, modified graphene, spherical alumina, carbon nanotubes, fumed silica and a dispersion stabilizer in a shear disperser, stirring and shearing and dispersing at a speed of 2500-3000 rpm / min for 1-3 hours to obtain a mixed solution;

[0087] (2) placing the mixed solution in step (1) in a microfluidizer for homogenization and dispersion, and performing 5-8 cycles of back and forth treatment at a homogenization pressure of 2000-4000 bar to obtain a homogenized solution;

[0088] (3) placing the homogenized solution obtained in step (2) together with water, viscosity regulator, corrosion inhibitor, defoamer and antioxidant in a blending kettle for blending and mixing, stirring at a speed of 500-800 rpm / min for 0.5-1 hour, and then performing vacuum degassing at room temperature, maintaining the vacuum degree between 0.03-0.1 MPa for 20-60 minutes, and finally obtaining a graphene nanofluid coolant.

[0089] The present invention will be described in detail below through examples.

[0090] In the following examples and comparative examples:

[0091] Thermal conductivity test standard is measured according to ASTM D2717 test method;

[0092] The specific heat capacity test standard is measured according to the SY / T 7517-2010 test method;

[0093] The stability test standard is measured according to the test method in Appendix D of GB 29743.1-2022;

[0094] The heat transfer corrosion test standard of cast aluminum alloy is measured according to the SH / T 0620 test method;

[0095] In the present invention, it should be noted that "parts" are equivalent to "parts by weight".

[0096] Example 1

[0097] This embodiment is intended to illustrate a graphene nanofluid coolant prepared by using the composition for preparing a graphene nanofluid coolant of the present invention.

[0098] The composition for preparing the graphene nanofluid coolant comprises: by mass, 60 parts of deionized water, 40 parts of ethylene glycol (purity ≥ 99.9%), 3.3 parts of modified graphene (specifically sulfonated graphene, with a sheet diameter of 11 μm and 5 layers), spherical alumina (with a particle size of 3 μm and a specific surface area of ​​700 m 2 / g) 1.5 parts, carbon nanotubes (tube diameter 8nm, length 120μm, specific surface area 2500m 2 / g) 0.6 parts, fumed silica (particle size 8nm, specific surface area 420m 2 / g) 0.7 parts, dispersion stabilizer (polyvinyl pyrrolidone) 0.5 parts, viscosity modifier (polyethylene glycol) 0.5 parts, corrosion inhibitor (isophthalic acid) 0.7 parts, defoaming agent (polydimethylsiloxane) 0.18 parts, antioxidant (2,6-di-tert-butylhydroquinone) 0.58 parts.

[0099] The method for preparing a graphene nanofluid coolant using the aforementioned composition comprises:

[0100] (1) First, ethylene glycol, modified graphene, spherical alumina, carbon nanotubes, fumed silica and a dispersion stabilizer are placed in a shear disperser and stirred and shear dispersed at a speed of 2500 rpm / min for 1 hour to obtain a mixed solution;

[0101] (2) Then, the mixed solution obtained in step (1) was placed in a microfluidizer for homogenization and dispersion, and the mixture was circulated back and forth for 5 times at a pressure of 2000 bar to obtain a homogenized solution;

[0102] (3) Then, the homogenized solution obtained in step (2) is placed in a blending kettle together with deionized water, a viscosity regulator, a corrosion inhibitor, a defoaming agent and an antioxidant for blending and mixing, stirred at a speed of 500 rpm / min for 0.5 hour, and vacuum degassed at room temperature, maintaining the vacuum degree at 0.03 MPa for 20 minutes, and finally obtaining a graphene nanofluid coolant.

[0103] Example 2

[0104] This embodiment is intended to illustrate a graphene nanofluid coolant prepared by using the composition for preparing a graphene nanofluid coolant of the present invention.

[0105] The composition for preparing the graphene nanofluid coolant comprises: by mass, 65 parts of deionized water, 35 parts of ethylene glycol (purity ≥ 99.9%), 3.5 parts of modified graphene (amidated graphene, with a sheet diameter of 12 μm and 4 layers), spherical alumina (with a particle size of 4 μm and a specific surface area of ​​650 m 2 / g) 1.8 parts, carbon nanotubes (tube diameter 6nm, length 110μm, specific surface area 3500m 2 / g) 0.7 parts, fumed silica (particle size 12nm, specific surface area 350m 2 / g) 0.8 parts, dispersion stabilizer (carboxymethyl cellulose) 0.8 parts, viscosity modifier (polyacrylamide) 0.6 parts, corrosion inhibitor (sebamic acid) 0.8 parts, defoamer (polyether modified polysiloxane) 0.2 parts, antioxidant (2,6-di-tert-butylhydroquinone) 0.6 parts.

[0106] The method for preparing a graphene nanofluid coolant using the aforementioned composition comprises:

[0107] (1) First, ethylene glycol, modified graphene, spherical alumina, carbon nanotubes, fumed silica and a dispersion stabilizer are placed in a shear disperser and stirred and shear dispersed at a speed of 2600 rpm / min for 1.5 hours to obtain a mixed solution;

[0108] (2) Then, the mixed solution obtained in step (1) was placed in a microfluidizer for homogenization and dispersion, and the mixture was circulated back and forth for 6 times at a pressure of 2500 bar to obtain a homogenized solution;

[0109] (3) Then, the homogenized solution obtained in step (2) is placed in a blending kettle together with deionized water, a viscosity regulator, a corrosion inhibitor, a defoaming agent and an antioxidant for blending and mixing, stirred at a speed of 580 rpm / min for 0.7 hours, and vacuum degassed at room temperature, maintaining the vacuum degree at 0.06 MPa for 30 minutes, and finally obtaining a graphene nanofluid coolant.

[0110] Example 3

[0111] This embodiment is intended to illustrate a graphene nanofluid coolant prepared by using the composition for preparing a graphene nanofluid coolant of the present invention.

[0112] The composition for preparing the graphene nanofluid coolant comprises: by mass, 70 parts of deionized water, 30 parts of ethylene glycol (purity ≥ 99.9%), 4 parts of modified graphene (hydroxylated graphene, with a sheet diameter of 15 μm and 3 layers), spherical alumina (with a particle size of 6 μm and a specific surface area of ​​500 m 2 / g) 2 parts, carbon nanotubes (tube diameter 4nm, length 90μm, specific surface area 4000m 2 / g) 0.8 parts, fumed silica (particle size 18nm, specific surface area 260m 2 / g) 0.9 parts, dispersion stabilizer (sodium dodecylbenzene sulfonate) 0.9 parts, viscosity modifier (hydroxypropyl methylcellulose) 0.7 parts, corrosion inhibitor (2-hydroxyphosphonoacetic acid) 1 part, defoamer (polyacrylic acid) 0.2 parts, antioxidant (dibenzothiazyl disulfide) 0.8 parts.

[0113] The method for preparing a graphene nanofluid coolant using the aforementioned composition comprises:

[0114] (1) First, ethylene glycol, modified graphene, spherical alumina, carbon nanotubes, fumed silica and a dispersion stabilizer are placed in a shear disperser and stirred and shear dispersed at a speed of 2700 rpm / min for 2 hours to obtain a mixed solution;

[0115] (2) Then, the mixed solution obtained in step (1) was placed in a microfluidizer for homogenization and dispersion, and the mixture was circulated back and forth for 6 times at a pressure of 3000 bar to obtain a homogenized solution;

[0116] (3) Then, the homogenized solution obtained in step (2) is placed in a blending kettle together with deionized water, a viscosity regulator, a corrosion inhibitor, a defoaming agent and an antioxidant for blending and mixing, stirred at a speed of 650 rpm / min for 0.8 hours, and vacuum degassed at room temperature, maintaining the vacuum degree at 0.08 MPa for 40 minutes, and finally obtaining a graphene nanofluid coolant.

[0117] Example 4

[0118] This embodiment is intended to illustrate a graphene nanofluid coolant prepared by using the composition for preparing a graphene nanofluid coolant of the present invention.

[0119] The composition for preparing the graphene nanofluid coolant comprises: by mass, 75 parts of deionized water, 25 parts of ethylene glycol (purity ≥ 99.9%), 4.5 parts of modified graphene (carboxylated graphene, with a sheet diameter of 17 μm and 2 layers), spherical alumina (with a particle size of 8 μm and a specific surface area of ​​350 m 2 / g) 2.5 parts, carbon nanotubes (tube diameter 4.5nm, length 70μm, specific surface area 4500m 2 / g) 0.9 parts, fumed silica (particle size 20nm, specific surface area 150m 2 / g) 1 part, dispersion stabilizer (hydrolyzed polymaleic anhydride) 1.2 parts, viscosity modifier (guar gum) 0.8 parts, corrosion inhibitor (aminotrimethylenephosphonic acid) 1.2 parts, defoaming agent (polymethacrylic acid) 0.3 parts, antioxidant (3,5-di-tert-butyl-4-hydroxybenzoic acid) 0.8 parts.

[0120] The method for preparing a graphene nanofluid coolant using the aforementioned composition comprises:

[0121] (1) First, ethylene glycol, modified graphene, spherical alumina, carbon nanotubes, fumed silica and a dispersion stabilizer are placed in a shear disperser and stirred and shear dispersed at a speed of 2800 rpm / min for 2.6 hours to obtain a mixed solution;

[0122] (2) Then, the mixed solution obtained in step (1) was placed in a microfluidizer for homogenization and dispersion, and the mixture was circulated back and forth for 7 times at a pressure of 3600 bar to obtain a homogenized solution;

[0123] (3) Then, the homogenized solution obtained in step (2) is placed in a blending kettle together with deionized water, a viscosity regulator, a corrosion inhibitor, a defoaming agent and an antioxidant for blending and mixing, stirred at a speed of 700 rpm / min for 0.9 hours, and vacuum degassed at room temperature, maintaining the vacuum degree at 0.09 MPa for 50 minutes, and finally obtaining a graphene nanofluid coolant.

[0124] Example 5

[0125] This embodiment is intended to illustrate a graphene nanofluid coolant prepared by using the composition for preparing a graphene nanofluid coolant of the present invention.

[0126] The composition for preparing the graphene nanofluid coolant comprises: by mass, 80 parts of deionized water, 20 parts of ethylene glycol (purity ≥ 99.9%), 5 parts of modified graphene (hydroxylated graphene, with a sheet diameter of 20 μm and a layer number of 1), spherical alumina (with a particle size of 10 μm and a specific surface area of ​​150 m 2 / g) 3 parts, carbon nanotubes (tube diameter 5nm, length 50μm, specific surface area 5000m 2 / g) 1 part, fumed silica (particle size 25nm, specific surface area 100m 2 / g) 1.2 parts, dispersion stabilizer (phosphonic acid-based polyacrylic acid) 1.5 parts, viscosity modifier (hydroxypropyl methylcellulose) 0.9 parts, corrosion inhibitor (cyclohexene-1,2-dicarboxylic acid) 1.5 parts, defoaming agent (dodecyl alcohol polyoxyethylene ether) 0.3 parts, antioxidant (4-hydroxy-2,6-di-tert-butylphenol) 1 part.

[0127] The method for preparing a graphene nanofluid coolant using the aforementioned composition comprises:

[0128] (1) First, ethylene glycol, modified graphene, spherical alumina, carbon nanotubes, fumed silica and a dispersion stabilizer are placed in a shear disperser and stirred and shear dispersed at a speed of 3000 rpm / min for 3 hours to obtain a mixed solution;

[0129] (2) Then, the mixed solution obtained in step (1) was placed in a microfluidizer for homogenization and dispersion, and the mixture was circulated back and forth for 8 times at a pressure of 4000 bar to obtain a homogenized solution;

[0130] (3) Then, the homogenized solution obtained in step (2) is placed in a blending kettle together with deionized water, a viscosity regulator, a corrosion inhibitor, a defoaming agent and an antioxidant for blending and mixing, stirred at a speed of 800 rpm / min for 1 hour, and vacuum degassed at room temperature, maintaining the vacuum degree at 0.1 MPa for 60 minutes, and finally obtaining a graphene nanofluid coolant.

[0131] Example 6

[0132] This embodiment is intended to illustrate a graphene nanofluid coolant prepared by using the composition for preparing a graphene nanofluid coolant of the present invention.

[0133] The composition for preparing the graphene nanofluid coolant comprises: by mass, 62 parts of deionized water, 38 parts of ethylene glycol (purity ≥ 99.9%), 3 parts of modified graphene (sulfonated graphene, with a sheet diameter of 10 μm and 5 layers), 3 parts of spherical alumina (with a particle size of 2 μm and a specific surface area of ​​750 m 2 / g) 1 part, carbon nanotubes (tube diameter 10nm, length 150μm, specific surface area 2000m 2 / g) 0.5 parts, fumed silica (particle size 5nm, specific surface area 600m 2 / g) 0.5 parts, dispersion stabilizer (phosphonic acid-based polyacrylic acid) 0.1 parts, viscosity modifier (hydroxypropyl methylcellulose) 0.3 parts, corrosion inhibitor (cyclohexene-1,2-dicarboxylic acid) 0.5 parts, defoaming agent (polyoxyethylene dodecyl alcohol ether) 0.1 parts, antioxidant (4-hydroxy-2,6-di-tert-butylphenol) 0.5 parts.

[0134] The method for preparing a graphene nanofluid coolant using the aforementioned composition comprises:

[0135] (1) First, ethylene glycol, modified graphene, spherical alumina, carbon nanotubes, fumed silica and a dispersion stabilizer are placed in a shear disperser and stirred and shear dispersed at a speed of 2500 rpm / min for 1.2 hours to obtain a mixed solution;

[0136] (2) Then, the mixed solution obtained in step (1) was placed in a microfluidizer for homogenization and dispersion, and the mixture was circulated back and forth for 5 times at a pressure of 2000 bar to obtain a homogenized solution;

[0137] (3) Then, the homogenized solution obtained in step (2) is placed in a blending kettle together with deionized water, a viscosity regulator, a corrosion inhibitor, a defoaming agent and an antioxidant for blending and mixing, stirred at a speed of 500 rpm / min for 0.5 hour, and vacuum degassed at room temperature, maintaining the vacuum degree at 0.03 MPa for 20 minutes, and finally obtaining a graphene nanofluid coolant.

[0138] Example 7

[0139] This embodiment is intended to illustrate a graphene nanofluid coolant prepared by using the composition for preparing a graphene nanofluid coolant of the present invention.

[0140] The composition for preparing the graphene nanofluid coolant comprises: by mass, 68 parts of deionized water, 32 parts of ethylene glycol (purity ≥ 99.9%), 3.2 parts of modified graphene (carboxylated graphene, with a sheet diameter of 10.5 μm and 5 layers), spherical alumina (with a particle size of 2.5 μm and a specific surface area of ​​720 m 2 / g) 1.2 parts, carbon nanotubes (tube diameter 9nm, length 130μm, specific surface area 2200m 2 / g) 0.55 parts, fumed silica (particle size 7nm, specific surface area 500m 2 / g) 0.6 parts, dispersion stabilizer (phosphonic acid-based polyacrylic acid) 0.2 parts, viscosity modifier (hydroxypropyl methylcellulose) 0.4 parts, corrosion inhibitor (cyclohexene-1,2-dicarboxylic acid) 0.55 parts, defoaming agent (dodecyl alcohol polyoxyethylene ether) 0.15 parts, antioxidant (4-hydroxy-2,6-di-tert-butylphenol) 0.55 parts.

[0141] The method for preparing a graphene nanofluid coolant using the aforementioned composition comprises:

[0142] (1) First, ethylene glycol, modified graphene, spherical alumina, carbon nanotubes, fumed silica and a dispersion stabilizer were placed in a shear disperser and stirred at a speed of 2600 rpm / min for 1.3 hours to obtain a mixed solution;

[0143] (2) Then, the mixed solution obtained in step (1) was placed in a microfluidizer for homogenization and dispersion, and the mixture was circulated back and forth for 6 times at a pressure of 2500 bar to obtain a homogenized solution;

[0144] (3) Then, the homogenized solution obtained in step (2) is placed in a blending kettle together with deionized water, a viscosity regulator, a corrosion inhibitor, a defoaming agent and an antioxidant for blending and mixing, stirred at a speed of 550 rpm / min for 0.6 hours, and vacuum degassed at room temperature, maintaining the vacuum degree at 0.08 MPa for 30 minutes, and finally obtaining a graphene nanofluid coolant.

[0145] Comparative Example 1

[0146] A commercially available nanofluid coolant is used, wherein the commercially available nanofluid coolant comprises the following components and component contents: 50 parts of ethylene glycol, 50 parts of water, 5 parts of nano zinc oxide, 1.2 parts of polyacrylic acid amine, 2 parts of sodium metasilicate, and 0.05 parts of polysiloxane stabilizer.

[0147] Comparative Example 2

[0148] The composition for preparing the nanofluid coolant includes: by mass, 80 parts of deionized water, 20 parts of ethylene glycol (purity ≥ 99.9%), spherical alumina (particle size 10 μm, specific surface area 150 m 2 / g) 3 parts, carbon nanotubes (tube diameter 5nm, length 50μm, specific surface area 5000m 2 / g) 1 part, fumed silica (particle size 25nm, specific surface area 100m 2 / g) 1.2 parts, dispersion stabilizer (phosphonic acid-based polyacrylic acid) 1.5 parts, viscosity modifier (hydroxypropyl methylcellulose) 0.9 parts, corrosion inhibitor (cyclohexene-1,2-dicarboxylic acid) 1.5 parts, defoaming agent (dodecyl alcohol polyoxyethylene ether) 0.3 parts, antioxidant (4-hydroxy-2,6-di-tert-butylphenol) 1 part.

[0149] The method for preparing a nanofluid coolant using the aforementioned composition comprises:

[0150] (1) First, ethylene glycol, spherical alumina, carbon nanotubes, fumed silica and a dispersion stabilizer were placed in a shear disperser and stirred and sheared at a speed of 3000 rpm / min for 3 hours to obtain a mixed solution;

[0151] (2) Then, the mixed solution obtained in step (1) was placed in a microfluidizer for homogenization and dispersion, and the mixture was circulated back and forth for 8 times at a pressure of 4000 bar to obtain a homogenized solution;

[0152] (3) Then, the homogenized solution obtained in step (2) is placed in a blending kettle together with deionized water, a viscosity regulator, a corrosion inhibitor, a defoaming agent and an antioxidant for blending and mixing, stirred at a speed of 800 rpm / min for 1 hour, and vacuum degassed at room temperature, maintaining the vacuum degree at 0.1 MPa for 60 minutes, and finally obtaining a nanofluid coolant.

[0153] Comparative Example 3

[0154] The composition for preparing the graphene nanofluid coolant comprises: by mass, 80 parts of deionized water, 20 parts of ethylene glycol (purity ≥ 99.9%), 5 parts of modified graphene (hydroxylated graphene, with a sheet diameter of 20 μm and a layer number of 1), spherical alumina (with a particle size of 10 μm and a specific surface area of ​​150 m 2 / g) 3 parts, carbon nanotubes (tube diameter 5nm, length 50μm, specific surface area 5000m 2 / g) 1 part, fumed silica (particle size 25nm, specific surface area 100m 2 / g) 1.2 parts, dispersion stabilizer (phosphonic acid-based polyacrylic acid) 1.5 parts, viscosity modifier (hydroxypropyl methylcellulose) 0.9 parts, corrosion inhibitor (cyclohexene-1,2-dicarboxylic acid) 3 parts, defoaming agent (dodecyl alcohol polyoxyethylene ether) 0.3 parts, antioxidant (4-hydroxy-2,6-di-tert-butylphenol) 1 part.

[0155] The method for preparing a graphene nanofluid coolant using the aforementioned composition comprises:

[0156] (1) First, ethylene glycol, modified graphene, spherical alumina, carbon nanotubes, fumed silica and a dispersion stabilizer are placed in a shear disperser and stirred and shear dispersed at a speed of 3000 rpm / min for 3 hours to obtain a mixed solution;

[0157] (2) Then, the mixed solution obtained in step (1) was placed in a microfluidizer for homogenization and dispersion, and the mixture was circulated back and forth for 8 times at a pressure of 4000 bar to obtain a homogenized solution;

[0158] (3) Then, the homogenized solution obtained in step (2) is placed in a blending kettle together with water, a viscosity regulator, a corrosion inhibitor, a defoaming agent and an antioxidant for blending and mixing, stirred at a speed of 800 rpm / min for 1 hour, and vacuum degassed at room temperature, maintaining the vacuum degree at 0.1 MPa for 60 minutes, and finally obtaining a graphene nanofluid coolant.

[0159] Comparative Example 4

[0160] The composition for preparing the graphene nanofluid coolant comprises: by mass, 80 parts of deionized water, 20 parts of ethylene glycol (purity ≥ 99.9%), 5 parts of unmodified graphene (i.e., ordinary graphene (sheet diameter 20 μm, number of layers 1), spherical alumina (particle size 10 μm, specific surface area 150 m 2 / g) 3 parts, carbon nanotubes (tube diameter 5nm, length 50μm, specific surface area 5000m 2 / g) 1 part, fumed silica (particle size 25nm, specific surface area 100m 2 / g) 1.2 parts, dispersion stabilizer (phosphonic acid-based polyacrylic acid) 1.5 parts, viscosity modifier (hydroxypropyl methylcellulose) 0.9 parts, corrosion inhibitor (cyclohexene-1,2-dicarboxylic acid) 1.5 parts, defoaming agent (dodecyl alcohol polyoxyethylene ether) 0.3 parts, antioxidant (4-hydroxy-2,6-di-tert-butylphenol) 1 part.

[0161] The method for preparing a graphene nanofluid coolant using the aforementioned composition comprises:

[0162] (1) First, ethylene glycol, unmodified graphene, spherical alumina, carbon nanotubes, fumed silica and a dispersion stabilizer are placed in a shear disperser and stirred and shear dispersed at a speed of 3000 rpm / min for 3 hours to obtain a mixed solution;

[0163] (2) Then, the mixed solution obtained in step (1) was placed in a microfluidizer for homogenization and dispersion, and the mixture was circulated back and forth for 8 times at a pressure of 4000 bar to obtain a homogenized solution;

[0164] (3) Then, the homogenized solution obtained in step (2) is placed in a blending kettle together with deionized water, a viscosity regulator, a corrosion inhibitor, a defoaming agent and an antioxidant for blending and mixing, stirred at a speed of 800 rpm / min for 1 hour, and vacuum degassed at room temperature, maintaining the vacuum degree at 0.1 MPa for 60 minutes, and finally obtaining a graphene nanofluid coolant.

[0165] Comparative Example 5

[0166] The composition for preparing the graphene nanofluid coolant comprises: by mass, 80 parts of deionized water, 20 parts of ethylene glycol (purity ≥ 99.9%), 5 parts of modified graphene (hydroxylated graphene, with a sheet diameter of 35 μm and 10 layers), spherical alumina (with a particle size of 10 μm and a specific surface area of ​​150 m 2 / g) 3 parts, carbon nanotubes (tube diameter 5nm, length 50μm, specific surface area 5000m 2 / g) 1 part, fumed silica (particle size 25nm, specific surface area 100m 2 / g) 1.2 parts, dispersion stabilizer (phosphonic acid-based polyacrylic acid) 1.5 parts, viscosity modifier (hydroxypropyl methylcellulose) 0.9 parts, corrosion inhibitor (cyclohexene-1,2-dicarboxylic acid) 1.5 parts, defoaming agent (dodecyl alcohol polyoxyethylene ether) 0.3 parts, antioxidant (4-hydroxy-2,6-di-tert-butylphenol) 1 part.

[0167] The method for preparing a graphene nanofluid coolant using the aforementioned composition comprises:

[0168] (1) First, ethylene glycol, modified graphene, spherical alumina, carbon nanotubes, fumed silica and a dispersion stabilizer are placed in a shear disperser and stirred and shear dispersed at a speed of 3000 rpm / min for 3 hours to obtain a mixed solution;

[0169] (2) Then, the mixed solution obtained in step (1) was placed in a microfluidizer for homogenization and dispersion, and the mixture was circulated back and forth for 8 times at a pressure of 4000 bar to obtain a homogenized solution;

[0170] (3) Then, the homogenized solution obtained in step (2) is placed in a blending kettle together with deionized water, a viscosity regulator, a corrosion inhibitor, a defoaming agent and an antioxidant for blending and mixing, stirred at a speed of 800 rpm / min for 1 hour, and vacuum degassed at room temperature, maintaining the vacuum degree at 0.1 MPa for 60 minutes, and finally obtaining a graphene nanofluid coolant.

[0171] Test Case

[0172] The graphene nanofluid coolants prepared in the above-mentioned Examples 1-7 and Comparative Examples 1-5 were tested respectively, and the results are shown in Table 1.

[0173] Table 1

[0174]

[0175] It can be seen from the results in Table 1 that the graphene nanofluid coolant prepared by the present invention has good thermal conductivity, can significantly improve the corrosion resistance of metal parts, and achieve a more effective protection effect.

[0176] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A composition for preparing a graphene nanofluid coolant, characterized in that: In parts by weight, the composition comprises: Water: 60-80 parts by weight; Ethylene glycol: 20-40 parts by weight; Modified graphene: 3-5 parts by weight; Spherical alumina: 1-3 parts by weight; Carbon nanotubes: 0.5-1 parts by weight; Corrosion inhibitor: 0.5-1.5 parts by weight; Fumed silica: 0.5-1.2 parts by weight.

2. The composition according to claim 1, wherein The modified graphene is selected from one or more of sulfonated graphene, amidated graphene, hydroxylated graphene and carboxylated graphene; And / or, the modified graphene is in the form of flakes, with a flake diameter of 10-20 μm and a number of layers ≤5.

3. The composition according to claim 1, wherein The particle size of the spherical alumina is 2-10 μm, and the specific surface area is 150-750 m 2 / g; And / or, the carbon nanotubes have a diameter of 5-10 nm, a length of 50-150 μm, and a specific surface area of ​​2000-5000 m 2 / g; And / or, the particle size of the fumed silica is 5-25 nm, and the specific surface area is 100-600 m 2 / g.

4. The composition according to any one of claims 1 to 3, wherein The composition further comprises: Dispersion stabilizer: 0.1-1.5 parts by weight; Viscosity modifier: 0.3-0.9 parts by weight; Defoaming agent: 0.1-0.3 parts by weight; Antioxidant: 0.5-1 parts by weight.

5. The composition according to claim 4, wherein The dispersion stabilizer is selected from one or more of polyvinyl pyrrolidone, carboxymethyl cellulose, sodium dodecylbenzene sulfonate, hydrolyzed polymaleic anhydride and phosphonic acid-based polyacrylic acid; and / or, the viscosity modifier is selected from one or more of polyethylene glycol, polyacrylamide, hydroxypropyl methylcellulose and guar gum; And / or, the corrosion inhibitor is selected from one or more of isophthalic acid, sebacic acid, 2-hydroxyphosphonoacetic acid, aminotri(methylenephosphonic acid) and cyclohexene-1,2-dicarboxylic acid; And / or, the defoaming agent is selected from one or more of polydimethylsiloxane, polyether-modified polysiloxane, polyacrylic acid, polymethacrylic acid and dodecyl alcohol polyoxyethylene ether; And / or, the antioxidant is selected from one or more of 2,6-di-tert-butylhydroquinone, butylated hydroxyanisole, dibenzothiazole disulfide, 3,5-di-tert-butyl-4-hydroxybenzoic acid and 4-hydroxy-2,6-di-tert-butylphenol.

6. A method for preparing a graphene nanofluid coolant using the composition according to any one of claims 1 to 5, characterized in that: The method includes: (1) contacting and mixing ethylene glycol, modified graphene, spherical alumina, carbon nanotubes, fumed silica and an optional dispersion stabilizer to obtain a mixed solution; (2) homogenizing the mixed solution to obtain a homogenized solution; (3) contacting the homogenized solution with water, an optional viscosity regulator, a corrosion inhibitor, an optional defoaming agent, and an optional antioxidant to blend and mix, and subjecting the mixture to vacuum degassing to obtain a graphene nanofluid coolant.

7. The method according to claim 6, wherein: In step (1), the mixing conditions include: stirring and shearing dispersion at a speed of 2500-3000 rpm for 1-3 hours to obtain a mixed solution; And / or, in step (2), the homogenization treatment conditions include: treating at a homogenization pressure of 2000-4000 bar to obtain a homogenized solution; And / or, in step (3), the blending and mixing conditions include: stirring at a speed of 500-800 rpm for 0.5-1 hour; And / or, in step (3), the conditions of the vacuum degassing treatment include: a vacuum degree between 0.03-0.1 MPa and a duration of 20-60 minutes.

8. A graphene nanofluid coolant prepared by the method according to claim 6 or 7.

9. The graphene nanofluid coolant according to claim 8, wherein: The thermal conductivity of the graphene nanofluid coolant at a temperature of 25° C. is 0.38-0.85 W / m·K, preferably 0.6-0.8 W / m·K; and / or, the specific heat capacity of the graphene nanofluid coolant at a temperature of 25° C. is 3.5-7.8 J / g·K, preferably 5-7 J / g·K; And / or, the heat transfer corrosion of the cast aluminum alloy of the graphene nanofluid coolant is 0.07-0.65 mg / cm 2 , preferably 0.1-0.3 mg / cm 2 .

10. Use of the graphene nanofluid coolant according to claim 8 or 9 in one or more of new energy vehicles, electronic equipment, data centers and servers.

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