Thermal Expansion and Diffusion Coefficients of Carbon Nanotube-Polymer Composites

TL;DR

This study uses molecular dynamics simulations to analyze how adding carbon nanotubes affects the thermal expansion, diffusion, and glass transition temperature of polyethylene composites, with implications for manufacturing and coatings.

Contribution

It provides new insights into the effects of carbon nanotubes on thermal and diffusion properties of polymer composites using detailed molecular dynamics simulations.

Findings

Carbon nanotubes increase the glass transition temperature (Tg).

They also raise the thermal expansion coefficients above Tg.

Diffusion coefficients are higher in composites with nanotubes.

Abstract

Classical molecular dynamics (MD) simulations employing Brenner potential for intra-nanotube interactions and Van der Waals forces for polymer-nanotube interfaces are used to invetigate the thermal expansion and diffusion characteristics of carbon nanotube-polyethylene composites. Additions of carbon nanotubes to polymer matrix are found to increase the glass transition temperature Tg, and thermal expansion and diffusion coefficients in the composite above Tg. These findings could have implications in CNT composite processing, coating and painting applications.