Insights into traction-separation phenomena of graphene-cis-1,4-polyisoprene interface using molecular dynamics

Abstract

Detailed investigations of graphene-cis-1,4-polyisoprene (PI) interfacial traction-separation (τ-δ) behavior and its causative phenomena in the molecular scale are addressed in this work, using Molecular Dynamics (MD) simulations. Configurations of dense amorphous cis-1,4-PI network have been generated and validated. Effects of temperature, separation rate and compressive load on τ-δ behavior are studied. The molecular level physics during interface separation in opening mode is explained using void dynamics and chain straightening. It is found that the evolution of voids and τ-δ behavior are strongly correlated at quasistatic separation rate. Interestingly, a viscous behavior is seen to develop at the interface as the separation rate increases. The magnitude of traction in the opening mode is higher than that in the sliding mode by nearly two orders of magnitude. It is also seen that the amount of polymer bound to graphene following complete separation in opening mode was independent of temperature, while it decreased with increase in separation rate.