▎ 摘　　要

NOVELTY - Preparing graphene-modified nanofluid heat transfer substance comprises e.g. (i) mixing graphite, phosphorus pentoxide, potassium permanganate and concentrated sulfuric acid, and reacting, (ii) mixing the pre-oxidized graphite, potassium permanganate, and concentrated sulfuric acid, reacting, centrifuging, washing the precipitate, and drying to obtain graphene oxide, (iii) in a solvent environment, mixing the graphene oxide and the reducing, adjusting the pH of the solution to 9-10, reacting, filtering, washing, and vacuum drying to obtain graphene, and (iv) mixing the graphene, glycerin, ketone or aldehyde, reacting, distilling the unreacted ketone or aldehyde under reduced pressure, and subjecting the resulting suspension to ultrasonic treatment in an ultrasonic cell pulverizer for 1-5 hours. USE - The method is useful for preparing graphene-modified nanofluid heat transfer substance. ADVANTAGE - The nanofluid has 92% thermal conductivity and 98%viscosity reduction; and is simple to prepare. DETAILED DESCRIPTION - Preparing graphene-modified nanofluid heat transfer substance comprises (i) mixing graphite, phosphorus pentoxide, potassium permanganate and concentrated sulfuric acid, and reacting at 10-50 degrees C for 1-8 hours, where the mass ratio of phosphorus pentoxide to potassium permanganate is 1: 1, the mass ratio of graphite to phosphorus pentoxide and potassium permanganate is 1:1-2:1, and the mass ratio of graphite to concentrated sulfuric acid is 3:1-5:1, filtering, washing and vacuum drying to obtain pre-oxidized graphite, (ii) mixing the pre-oxidized graphite, potassium permanganate, and concentrated sulfuric acid, reacting at 0-50 degrees C for 2-5 hours, where the mass ratio of pre-oxidized graphite to potassium permanganate is 1:3-1:5, and the mass ratio of pre-oxidized graphite to concentrated sulfuric acid is 1:30-1:50, neutralizing the unreacted oxidant with a 30% aqueous solution of hydrogen peroxide, centrifuging, washing the precipitate 3-5 times with an aqueous solution of a water-soluble organic solvent as a washing solvent, and drying under vacuum to obtain graphene oxide, (iii) in a solvent environment, mixing the graphene oxide and the reducing at a mass ratio of 1:30-1:50, and the mass to volume ratio of the graphene oxide to the solvent is 1:1-1:3 (g/l), adjusting the pH of the solution to 9-10, reacting at 80-120 degrees C for 12-24 hours, filtering, washing, and vacuum drying to obtain graphene, and (iv) mixing the graphene, glycerin, ketone or aldehyde, reacting at 80-150 degrees C for 2-12 hours, where the mass ratio of graphene to glycerol is 0.216-1.264%, the molar ratio of glycerol to ketone or aldehyde is 1:3-1:5, distilling the unreacted ketone or aldehyde under reduced pressure, and subjecting the resulting suspension to ultrasonic treatment in an ultrasonic cell pulverizer for 1-5 hours. An INDEPENDENT CLAIM is also included for graphene-modified nanofluid heat transfer substance is prepared by above method.