▎ 摘　　要

NOVELTY - Composite comprises a graphene oxide, and a nanodiamond that is bonded on a surface of the graphene oxide. USE - The composite is useful in nanofluid, which is used in vehicle (all claimed), thermal management system, and various apparatuses and systems. ADVANTAGE - The composite exhibits improved dispersion stability and corrosion stability and has substantially improved thermal conductivity. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) manufacturing the composite, comprising preparing the 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; and (2) nanofluid comprising the complex and a polar fluid.