▎ 摘　　要

NOVELTY - Method for preparing hybrid double-coated boron nitride/graphene insulating and thermally conductive silicone grease, by (i) adding boron nitride to solvent, and using ultrasonic-assisted high-speed shearing and stirring to peel and disperse, (ii) taking part of large-particle boron nitride nanosheet dispersion and adding to mill, and using telecentric ball mill to peel and disperse, (iii) adding alcohol and organic solvent to deionized water, adding zinc nitrate to mixed solution, heating, reacting, and performing distillation to obtain zinc phenol/phenol mixed solution, (iv) mixing boron nitride nanosheet dispersions, adding graphene, mixing with zinc carbonate/phenol mixed solution, adding formaldehyde, and reacting, and (v) adding dilute sulfuric acid to zinc oxide and phenolic prepolymer double-coated boron nitride/graphene dispersion, filtering, drying to obtain phenolic resin-zinc oxide mixed double-coated powder boron nitride/graphene powder, and mixing with organosilicone. USE - The method is useful for preparing hybrid double-coated boron nitride/graphene insulating and thermally conductive silicone grease. ADVANTAGE - The thermal conductive silicone grease has excellent thermal conductivity and simple preparation method, and is suitable for large scale production. DETAILED DESCRIPTION - Method for preparing hybrid double-coated boron nitride/graphene insulating and thermally conductive silicone grease, involves (i) taking boron nitride, solvent and dispersant, adding boron nitride to the solvent, and using ultrasonic-assisted high-speed shearing and stirring to peel and disperse to prepare large-particle boron nitride nanosheet dispersion, (ii) taking part of the large-particle boron nitride nanosheet dispersion prepared in step (i) and adding to a mill, and using a telecentric ball mill to peel and disperse to prepare a dispersion of small particles of boron nitride nanosheet with a suitable aspect ratio, (iii) taking phenol, zinc nitrate, alcohol, organic solvent and deionized water, adding alcohol and organic solvent to deionized water, stirring to form a uniformly mixed solution, adding zinc nitrate to the mixed solution, heating at 30-100 degrees C while stirring, dripping to the mixed solution, reacting for 0.5-10 hours in the presence of condenser, and performing distillation under reduced pressure to obtain a zinc phenol/phenol mixed solution, (iv) uniformly mixing the boron nitride nanosheet dispersions prepared in step (i) and step (ii), adding graphene, ultrasonically uniformly dispersing, mixing with the zinc carbonate/phenol mixed solution prepared in step (iii), adding formaldehyde, adjusting the pH of the solution to 8-12 by sodium hydroxide, and reacting at 30-100 degrees C for 1-24 hours to obtain zinc oxide and phenolic prepolymer double-coated boron nitride/graphene dispersion, and (v) adding dilute sulfuric acid to the zinc oxide and phenolic prepolymer double-coated boron nitride/graphene dispersion prepared in step (iv) to adjust the pH of the solution to 3-5, stirring at 30-100 degrees C for 0.5-10 hours, filtering, cleaning, drying to obtain phenolic resin-zinc oxide mixed double-coated powder boron nitride/graphene powder, and uniformly mixing with organosilicone to obtain the mixed double-coated boron nitride/graphene insulating and thermal conductive grease.