▎ 摘　　要

NOVELTY - A metal oxide-graphene composite fluid comprises metal oxide nano-fluid and graphene nano-fluid in the mass ratio of 10-1:1. USE - Metal oxide-graphene composite fluid used as heat-conducting fluid for heat pipe (claimed). ADVANTAGE - The composite fluid has simple preparation, excellent stability, particle dispersion, thermal conductivity, a thermal resistance of 0.145 degrees C/W and will not undergo large-scale sedimentation for 20-30 days. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for the preparation of the metal oxide-graphene composite fluid which involves step (1), pouring a base liquid comprising at least one of water, ethanol and methanol into a beaker, adding 1-10 g/L metal oxide nano-powder and surfactant comprising one of sodium dodecylbenzene sulfonate, cetyltrimethylammonium bromide or polyvinylpyrrolidone in the mass ratio of 1:1-10, stirring, ultrasonically dispersing and centrifuging to obtain the metal oxide nano-fluid, step(2), grinding crystalline flake graphite, adding a base liquid comprising at least one of water, ethanol, methanol, and 1-10g/L graphene and a surfactant comprising sodium dodecylbenzene sulfonate, cetyltrimethylammonium bromide or polyvinylpyrrolidone in the mass ratio of 1:1-10, ball milling using 0.5-2 %mass (of the base liquid) ceramic ball, ultrasonically dispersing, centrifuging and taking the supernatant to obtain the graphene nano-fluid, and step (3) mixing and ball milling the metal oxide nano-fluid and graphene nano-fluid, ultrasonically dispersing, centrifuging and taking the supernatant.