▎ 摘　　要

NOVELTY - Preparing composite base oil includes adding graphene powder into base oil, and mixing uniformly to obtain composite base oil for lubricating oil. The graphene powder meets the requirements of condition one: The graphene powder is dispersed in 10% ethanol aqueous solution according to the ratio of 0.1 mg/ml, where the absorbance is 0.75-0.80 under the light of 630nm wavelength and 500W power, and condition two: the graphene powder is dispersed in the aqueous solution at a ratio of 10 mg/ml, where the kinematic viscosity at 25°C satisfies 1±10%Pa.s@0.01s-1, 0.6±10%Pa.s@0.1s-1, 0.15±10%Pa.s@1s-1, 0.08±10%Pa.s@10s-1 and 0.05±10%Pa.s@100s-1. USE - The method is useful for preparing composite base oil, which is used for lubricating oil. ADVANTAGE - The method adopts suitable graphene characterization conditions to screen graphene powders with suitable conditions, and achieves the effect of improving the lubricating effect of lubricating oil and maintaining high stability. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a composite base oil for lubricating oil, where the composite base oil is dispersed with 0.0001-0.1wt.% graphene, and the graphene meets the requirements of the following conditions: Condition (1) the graphene powder is dispersed in 10% ethanol aqueous solution according to the ratio of 0.1 mg/ml, and the absorbance is 0.75-0.80 under the light of 630nm wavelength and 500 W power, and Condition (2) the graphene powder is dispersed in the aqueous solution at a ratio of 10 mg/ml, where the kinematic viscosity meets 1±0.5%Pa.s@0.01s-1, 0.6±0.5%Pa.s@0.1s1, 0.15±0.5%Pa.s@1s-1, 0.08±0.5%Pa.s@10s-1 and 0.05±0.5%Pa.s@100s-1. DESCRIPTION OF DRAWING(S) - The drawing shows a structure schematic diagram of a device for preparing graphene powder. 110Level variable diameter rotating channel 111First circulating pump 112First shell 120First storage tank 121Valve 132Second shell 133Second rotating shaft