Dynamic Study of Deformation and Adhesion of an Amorphous Polyethylene/Graphene Interface: A Simulation Study

In this paper, molecular dynamics tensile simulations of an amorphous polyethylene/graphene (PE/G) interface are carried out to investigate its adhesion strength. The effect of PE chain length and number and functionalization of G surface on the tensile behavior and interfacial adhesion is studied. The results show that the adhesion strength enhances with increasing chain length and number of the PE chains. In addition, the functionalization of G surface causes an increase in the adhesion strength comparing to unfunctionalized G due to deformation of a larger volume of the PE chains relying on the functionalized G. The contribution of bond length, bond angle, torsional potentials, and nonbonded energy is estimated as a function of interface elongation to clarify the deformation mechanisms within different tensile regions. The energy partitioning results indicate that the elastic, yield, and early postyielding regions are mostly controlled by the nonbonded interactions. However, the dihedral motions of the chains in addition to nonbonded interactions show a significant role in the disentanglement region, a part of postyielding and separation region. Furthermore, the simulation results exhibit how the internal mechanism associated with density profile, chain entanglements, and ordering can be evolved with increasing the interface elongation. (Figure presented.).