Graphene oxide-nanodiamond composite, manufacturing method thereof, and nanofluid including the same

Abstract

Disclosed herein is a composite comprising a graphene oxide and a nanodiamond that is chemically bonded on a surface of the graphene oxide.

What is claimed is: 
     
         1 . A composite, comprising:
 a graphene oxide; and   a nanodiamond that is bonded on a surface of the graphene oxide.   
     
     
         2 . The composite of  claim 1 , wherein the graphene oxide and the nanodiamond are chemically bonded by a linker group selected from the group consisting of an alkylene, a cycloalkylene, a bivalent aromatic ring group, —CO—O, —S—, —O—, —CO—, —SO 2 —, —N(R)— wherein R is a hydrogen atom or an alkyl group, and a combination thereof. 
     
     
         3 . The composite of  claim 1 , wherein the graphene oxide and the nanodiamond are bonded by —CO—O—. 
     
     
         4 . The composite of  claim 1 , wherein a thickness of the graphene oxide is about 1 to 2 nm, and a diameter thereof is about 1 to 3 μm. 
     
     
         5 . The composite of  claim 1 , wherein an average diameter of the nanodiamond is about 3 to 10 nm. 
     
     
         6 . The composite of  claim 1 , wherein an amount of about 50 to 150 parts by weight of the nanodiamond based on 100 parts by weight of the graphene oxide are chemically bonded. 
     
     
         7 . A method of manufacturing a composite comprising a graphene oxide and a nanodiamond, comprising:
 preparing a nanodiamond;   attaching a functional group on a surface of the nanodiamond by heat-treating the nanodiamond;   dispersing the nanodiamond comprising the functional group in a first solvent to prepare a nanodiamond dispersion;   dispersing a graphene oxide in a second solvent to prepare a graphene oxide dispersion; and   mixing the graphene oxide dispersion and the nanodiamond dispersion; and   forming a bond between the graphene oxide and the nanodiamond.   
     
     
         8 . The method of  claim 7 , wherein an average diameter of the nanodiamond is about 3 to 10 nm. 
     
     
         9 . The method of  claim 7 , wherein
 the functional group is attached on the surface of the nanodiamond by heat-treating the nanodiamond at a temperature of about 400° C. to 500° C. for about 1 to 3 h.   
     
     
         10 . The method of  claim 7 , wherein the functional group attached on the surface of the nanodiamond is —COOH. 
     
     
         11 . The method of  claim 7 , wherein the nanodiamond dispersion further comprises a catalyst. 
     
     
         12 . The method of  claim 11 , wherein the catalyst is one or more selected from the group consisting of N,N′-dicyclohexylcarbodiimide (DCC) and 4-(dimethyl amino)pyridine (DMAP). 
     
     
         13 . The method of  claim 7 , wherein the first solvent is one or more selected from the group consisting of an amide-based solvent, an ether-based solvent, and a halogenated solvent. 
     
     
         14 . The method of  claim 7 , wherein when the graphene oxide is dispersed in the second solvent, a hydroxyl group or an alkyl group is attached on the surface of the graphene oxide. 
     
     
         15 . The method of  claim 7 , wherein when the graphene oxide is dispersed in the second solvent, a thickness of the graphene oxide is about 1 to 2 nm, and a diameter thereof is about 1 to 3 μm. 
     
     
         16 . The method of  claim 7 , wherein an amount of about 50 to 150 parts by weight of the nanodiamond based on 100 parts by weight of the graphene oxide are mixed with the graphene oxide to form the bond between the graphene oxide and the nanodiamond. 
     
     
         17 . The method of  claim 7 , wherein the bond between the graphene oxide and the nanodiamond is formed by esterification reaction. 
     
     
         18 . A nanofluid comprising a complex of  claim 1  and a polar fluid. 
     
     
         19 . The nanofluid of  claim 18 , wherein the polar fluid is water, ethylene glycol, propylene glycol, or a combination thereof. 
     
     
         20 . A vehicle comprising a nanofluid of  claim 18 .