Molecular dynamics simulations of flexible polymer chains wrapping single-walled carbon nanotubes

Abstract

The goal of this study is to explore the interface between single-walled carbon nanotubes (SWCNTs) and polymer chains with flexible backbones in vacuo via molecular dynamics (MD) simulations. These simulations investigate whether the polymers prefer to wrap the SWCNT, what the molecular details of that interface are, and how the interfacial interaction is affected by the chemical composition and structure of the polymer. The simulations indicate that polymers with flexible backbones tend to wrap around the SWCNT, although not in any distinct conformation; no helical conformations were observed. PAN with the cyano side group showed a preference for transversing the length of the SWCNT rather than wrapping around its diameter, and the cyano group prefers to align parallel to the SWCNT surface. Flexible backbone polymers with bulky and aromatic side groups such as PS and PMMA prefer intrachain coiling rather than wrapping the SWCNT. Moment of inertia plots as a function of time quantify the interplay between intrachain coiling and adsorption to the SWCNT surface.