Large scale production of high aspect ratio graphite nanoplatelets with tunable oxygen functionality

High aspect ratio graphite nanoplatelets with tunable oxygen functionality are prepared using a two-step scalable process consisting of expansion by thermal plasma processing followed by exfoliation with ultrasonic processing. The result of this process is graphite nanoplatelets in high yield with an average particle size distribution ranging from monolayer graphene up to 10 nm in thickness, 1 to 30 mu m in length/width, and a tunable carbon to oxygen (C/O) ratio from 50 to 200 without requiring any special separation or isolation techniques such as sedimentation or centrifugation. It has been demonstrated for the first time that an intermediate level of oxygen functionalization improves the ability to exfoliate expanded graphite without having a detrimental effect on electrical conductivity.