▎ 摘　　要

NOVELTY - A modified coating comprises 1-20 wt.% graphene, 1-20 wt.% carbon nanotube, 1-20 wt.% nano-aluminum oxide, 0.1-1 wt.% dispersant, 0.1-1 wt.% silane coupling agent and 40-90 wt.% silicone oil. The modified coating is prepared by simultaneously performing acidification treatment of graphene and carbon nanotube, modifying surface coating of nano-aluminum oxide, graphene and carbon nanotube, mixing coated modified graphene and carbon nanotube with silicone oil. USE - The modified coating is useful for thermal interface material in high power LED, smart device and energy automobile. ADVANTAGE - The modified coating has excellent thermal conductivity. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation method of modified coating, which involves carrying out acidified processing of graphene and carbon nanotube, mixing graphene powder and carbon nanotube with mixed acid, where the mixed acid is 70-98% concentrated sulfuric acid or 65-80% concentrated nitric acid in ratio of 1:0.5-1.5 and reflowing at 70-90 degrees C for 3-8 hours, filtering and washing, then placing in a vacuum drying box and drying at 90-110 degrees C for 5-15 hours to obtain graphene acidified mixed powder, placing graphene acidified mixed powder in a ball grinding tank, then adding nano-aluminum oxide, pouring into 5-15 anhydrous ethanol, carrying out ball milling for 3-8 hours and drying the mixture in a blast oven 90-110 degrees C for 1-3 hours, filling argon gas, then placing in a tubular furnace for 1-3 hours, mixing graphene, carbon nanotube and silicone oil, then adding dispersant and silane coupling agent, stirring and defoaming.