Molecular dynamics simulations of the filling and decorating of carbon nanotubules

Carbon nanotubes (CNTs) have been proposed as excellent materials for the c onstruction of new, precisely tailored ultrafiltration membranes and as pro mising fibres for the construction of new, stronger composite materials. In this paper classical molecular dynamics simulations are used to investigat e the potential use of CNTs in these applications. Functional groups have b een covalently attached to the walls of CNTs to provide more extensive inte ractions between these new fibres and a polymer matrix. We examine the effe cts of these attachments on the mechanical properties of the tubules. The d iffusive molecular flow of methane, ethane and ethylene through single tubu les at room temperature are also studied. The simulations predict normal-mo de molecular diffusion for methane. However, diffusion that is intermediate between normal-mode and single-file diffusion is predicted for ethane and ethylene. These diffusion results are found to be similar to results predic ted for molecular diffusion in zeolites.