▎ 摘　　要

NOVELTY - Production of graphene nanoplatelets involves expanding flakes of intercalated graphite having lateral size of 500 mu m or less by exposing flakes to 1300-12000 degrees C for a time of less than 2 seconds, dispersing in dispersing medium, and subjecting dispersion to exfoliation and size reduction treatment by high pressure homogenization in which the expanded graphite is pumped at a pressure above 35 MPa through one or more micro-channels or necks. The particles of expanded graphite are subjected to shear stresses and are collided at an energy level from 5-200 Wh/g. USE - Production of graphene nanoplatelets (claimed) used as additive or component of elastomeric compositions for tires, paints and silicone compositions, compositions for treating articles such as textiles. ADVANTAGE - The method economically provides graphene nanoplatelets with very small size, high aspect ratio, low oxygen content, with low energy consumption. DETAILED DESCRIPTION - Production of graphene nanoplatelets having carbon to oxygen ratio of 100:1 or more involves expanding flakes of intercalated graphite having lateral size of 500 mu m or less by exposing flakes to 1300-12000 degrees C for a time of less than 2 seconds, dispersing in dispersing medium, and subjecting to exfoliation and size reduction treatment by high-pressure homogenization in a homogenizer in which the expanded graphite is pumped at a pressure above 35 MPa through one or more micro-channels or necks having a transverse section of not more than 500 mu m. The particles of expanded graphite are subjected to shear stresses and collided at an energy level from 5-200 Wh/g. An INDEPENDENT CLAIM is included for Pristine graphene nanoplatelets, in which at least 90% have lateral size (x, y) of 50 to less than 10000 nm, and a thickness (z) of 0.34-50 nm, and the lateral size being more than the thickness (x, y greater than z).