Molecular-scale mechanics of a crystalline polyethylene interface formed by projection of carbon nanotube structures

Abstract

The semicrystalline nature of polymer chains induced by the intrusion of carbon nanotubes (CNTs) is a decisive factor in understanding the properties of interfacial regions. Herein, the structural and mechanical behavior of polyethylene (PE) formed around CNT surfaces were determined using a combination of classical molecular dynamics simulations and subcontinuum-scale analysis. The results suggest that inserting CNTs into the polymer domain forces the PE chains to align along the longitudinal axis of the CNTs. The interface functions as a nucleating agent, and the area occupied by the crystalline phase propagates radially as PE chains are stacked over long distances. The crystalline PE, grown with CNT as the central axis, exhibits extreme mechanical anisotropy, particularly for normal and shear deformations in the transverse direction. Therefore, this study provides an important theoretical guideline for understanding polymeric semi-crystals around CNTs.