Frictional characteristics of exfoliated and epitaxial graphene

TL;DR

This study measures the friction coefficients of exfoliated and epitaxial graphene, revealing low friction and high pressure resistance, highlighting graphene's potential for antiwear coatings.

Contribution

It provides experimental data on the frictional properties of different graphene types and layer counts under ambient conditions.

Findings

Friction coefficients of ~0.03 for monolayer, bilayer, and trilayer graphene.

Pristine graphene has lower friction than oxygen plasma-treated disordered graphene.

Graphene exhibits high pressure resistance, suitable for antiwear applications.

Abstract

To determine the friction coefficient of graphene, micro-scale scratch tests are conducted on exfoliated and epitaxial graphene at ambient conditions. The experimental results show that the monolayer, bilayer, and trilayer graphene all yield friction coefficients of approximately 0.03. The friction coefficient of pristine graphene is less than that of disordered graphene, which is treated by oxygen plasma. Ramping force scratch tests are performed on graphene with various numbers of layers to determine the normal load required for the probe to penetrate graphene. A very low friction coefficient and also its high pressure resistance make graphene a promising material for antiwear coatings.