Surface Diffusion of C₁–C₃ Alcohols on Multiwall Carbon Nanotubes

Abstract

The diffusion of methanol, ethanol, and 2-propanol using individual multiwall carbon nanotubes (MWCNT) and MWCNT bundles was investigated for the first time via application of the quartz crystal microbalance. At small times, the release of alcohol obeys the advective mechanism. In contrast, no deviations from Fick’s law were justified at large times. This situation holds for either individual MWCNTs or MWCNT bundles. The utilized MWCNTs are mainly closed from both ends. Therefore, the alcohol release is controlled by surface diffusion. The measured surface diffusivity is in the order of 10-13 m2/s. The obtained diffusivities are in close proximity with the known surface diffusion coefficients on carbon materials.