An experimental investigation on the tangential interfacial properties of graphene: Size effect

The size-dependent mechanical properties and the edge effect of the tangential interface between graphene and a polyethylene terephthalate substrate (PET) are investigated. The interfacial mechanical parameters of graphene with seven different lengths are measured by in-situ Raman spectroscopy experiments. New phenomena are observed, such as the existence of the edge effect in the interfacial stress/strain transfer process, and the length of the edge of the interface can be affected by the size of graphene. Additionally, the interfacial shear stress exhibits a size effect, with its value significantly decreasing with an increase of the length of graphene. However, the ultimate stiffness and failure strength of the interface are size-independent as they are constant regardless of the length of graphene. (C) 2015 The Authors. Published by Elsevier B.V.