METHOD FOR PREPARING COMPOSITES ON BASIS OF GRAPHENE BONDING

• US 20200131405A1
• Filed: 03/13/2018
• Published: 04/30/2020
• Est. Priority Date: 05/27/2017
• Status: Active Grant

• Current Assignee: Hangzhou Gaoxi Technology Co., Ltd.
• Original Assignee: Hangzhou Gaoxi Technology Co., Ltd.
• Inventors: GAO, CHAO, LI, ZHENG, ZHANG, CHUNXIAO, CHANG, DAN, CHEN, CHEN, GAO, WEIWEI, GUO, YAN, HAN, YI
• Granted Patent: US 11,542,411 B2
• Time in Patent Office: Days
• CPC Class Codes: C01B 2204/04 Specific amount of layers or specific thickness
• CPC Class Codes: C01B 2204/24 Thermal properties
• CPC Class Codes: C01B 32/184 Preparation
• CPC Class Codes: C01B 32/194 After-treatment
• CPC Class Codes: C01B 32/198 Graphene oxide
• CPC Class Codes: C01P 2004/03 obtained by SEM
• CPC Class Codes: C01P 2004/20 extending in two dimensions, e.g. plate-like
• CPC Class Codes: C01P 2006/32 Thermal properties
• CPC Class Codes: C08K 3/042 Graphene or derivatives, e.g. graphene oxides
• CPC Class Codes: C09J 1/00 Adhesives based on inorganic constituents
• CPC Class Codes: C09J 2301/208 the adhesive layer being constituted by at least two or more adjacent or superposed adhesive layers, e.g. multilayer adhesive
• CPC Class Codes: C09J 2301/408 additives as essential feature of the adhesive layer
• CPC Class Codes: C09J 2400/10 Presence of inorganic materials
• CPC Class Codes: C09J 5/00 Adhesive processes in general; Adhesive processes not provided for elsewhere, e.g. relating to primers
• CPC Class Codes: C09J 5/06 involving heating of the applied adhesive
• CPC Class Codes: C09J 7/10 without carriers
• CPC Class Codes: C09J 9/00 Adhesives characterised by their physical nature or the effects produced, e.g. glue sticks C09J7/00 takes precedence
• CPC Class Codes: C09K 5/14 Solid materials, e.g. powdery or granular
• CPC Class Codes: D06M 11/74 with carbon or graphite; with carbides; with graphitic acids or their salts

Abstract

The invention utilizes swelling and fusion effects of graphene oxide in a solvent to implement cross-linked bonding of a graphene material itself and materials such as polymers, metal, paper, glass, carbon materials, and ceramics. The present invention not only overcomes the shortcoming in traditional adhesives of residual formaldehyde, but also has short drying time, high bonding strength and high corrosion resistance. The present invention is widely applied in the fields of aviation, aerospace, automobiles, machinery, construction, chemical, light industry, electronics, electrical appliances, and daily life, etc.

Claims

1-18. -18. (canceled)

19. A method for preparing a highly thermally conductive thick graphene film, wherein the thickness is greater than 50 μ

m, the porosity is 5-40%, the in-plane thermal conductivity is 1000-2000 W/mK;

the pleat density on the graphene sheet is controlled to 50-500 mm/mm2, and the graphene sheet has few defects and has an ID/TG ratio of <

0.02;

there is no delamination in the graphene thick film, and the distance between any two adjacent graphene sheets is less than 20 nm graphene; and

the preparation method comprises the following steps;

(1) formulating graphene oxide having an average size greater than 50 μ

m into an aqueous graphene oxide solution having a concentration of 1 to 20 mg/mL, and naturally drying after a film is formed from the solution, to obtain a graphene oxide film;

(2) laminating a plurality of graphene oxide films specifically by uniformly spraying a liquid on the surface of the graphene oxide films to swell the surface, and then bonding the plurality of graphene oxide films together in the thickness direction;

(3) drying the bonded graphene oxide composite film in an oven at a temperature of not higher than 40°

C.;

(4) transferring the dried graphene oxide composite film to a hot-pressing chamber of a hot press, heating to 200°

C. at a ramping rate of 0.1 to 5°

C./min and then hot pressing by repeating the following hot-pressing process 8-10 times;

maintaining the pressure at 20 MPa for 1 hr, gradually releasing the pressure to 0 MPa, and evacuating the hot-pressing chamber for 5 min to a vacuum level of −

100-10 KPa;

then heating to 300°

C. for 0.5 hr at a ramping rate of 0.1-5°

C./min, and then hot pressing by repeating the following hot pressing process 4-6 times;

maintaining the pressure at 60 MPa for 1 hr, gradually releasing the pressure to 0 MPa, and evacuating the hot-pressing chamber for 5 min to a vacuum level of −

100-10 KPa; and

naturally cooling after hot pressing; and

(5) heating the graphene oxide film that is hot pressed in Step 4 to a temperature of 1800-3000°

C. at a ramping rate of 1-20°

C./min under an inert gas atmosphere and further hot pressing, wherein the temperature and pressure are held for 0.5-8 hrs, and the pressure is 10 MPa; and

pressing at a reduced temperature, to obtain a highly thermally conductive thick graphene film.

20. The method for preparing a highly thermally conductive thick graphene film according to claim 19, wherein the thickness of the graphene oxide film prepared in Step 1 is 1 to 30 μ

m.

21. The method for preparing a highly thermally conductive thick graphene film according to claim 19, wherein the film forming method in Step 1 is selected from suction filtration, blade coating, spin coating, spray coating, and dip coating.

22. The method for preparing a highly thermally conductive thick graphene film according to claim 19, wherein the carbon/oxygen ratio in the graphene oxide film prepared in Step 1 is ranged from 1.8 to 2.1.

23. The method for preparing a highly thermally conductive thick graphene film according to claim 19, wherein the liquid for spraying in Step 2 is deionized water, a graphene oxide aqueous solution having a concentration of 1 to 10 mg/mL, or other solutions containing deionized water.

24. A graphene oxide adhesive, comprising a solvent and graphene oxide dispersed in the solvent, wherein the concentration of the graphene oxide is 4 mg/ml or higher, the C/O ratio is 3:

1 or less, and the proportion of single-layer graphene oxide is greater than 80%; and

the size of the graphene oxide sheet is 1 to 100 μ

m, where the amount of graphene oxide sheets with a size of less than 5 μ

m is not more than 10%, and the amount of graphene oxide sheets with a size of greater than 30 μ

m is not less than 60%.

25. The graphene oxide adhesive according to claim 24, wherein the solvent is water or DMF.

26. (canceled)

27. A method for bonding materials with graphene, comprising uniformly coating a graphene oxide solution between a plurality of materials to be bonded, drying, and reducing, to bond the materials to be bonded by graphene, wherein in the graphene oxide solution, the size of the graphene oxide sheet is 1 to 100 μ

m, where the amount of graphene oxide sheets with a size of less than 5 μ

m is not more than 10%, and the amount of graphene oxide sheets with a size of greater than 30 μ

m is not less than 65%;

the proportion of single-layer graphene oxide is greater than 80%; and

the concentration of graphene oxide is 4 mg/mL or higher.

28. The method according to claim 27, wherein the C/O ratio in the graphene after reduction is 4:

1.

29. The method according to claim 27, wherein the solvent is water, ethanol, or N,N-dimethyl formamide (DMF).

30. The method according to claim 27, wherein the reduction method is chemical reduction with hydroiodic acid or hydrazine hydrate vapor at 80-100°

C. or thermal reduction by slowing heating to 100-500°

C. at a ramping rate of 1°

C./min in a pressurized or vacuum state.