Nanoscale frictional characteristics of graphene nanoribbons

We compare nanoscale frictional characteristics of three types of chemically treated graphene nanoribbons (GNRs) via atomic force microscope. Measurements in both ambient and low humidity conditions demonstrate that covalently bonded functional groups have a significant impact on the frictional response of GNRs. The measured tip-sample adhesion forces seem to support the observed friction force dependence on functionalizations, and the friction and adhesion differences could also be attributed to the surface reactivity and hydrophilicity differences induced by different chemical functionalization schemes.