Acetylene Sorption Dynamics in Carbon Nanotubes

Abstract

AbstractSingle‐walled and multi‐walled carbon nanotubes (SWNT and MWNT, resp.) were prepared by applying the catalytic chemical vapor deposition (CCVD) technique. Different nanotube samples were obtained from the as‐synthesized carbon/catalyst composites by treatments applied to remove the catalyst and the amorphous carbon. The dynamic and equilibrium adsorption properties of the samples were compared. Acetylene was used as an adsorptive probe. The sorption mass‐transport properties have been characterized by applying the frequency response (FR) technique. Results reflected that the surface functional groups, generated by an oxidative treatment, have significant influence on both the static and the dynamic acetylene sorption properties of the carbon nanotube materials. The rate of acetylene mass transport was governed by the rate of sorption in all the samples, except in MWNT after oxidative treatment, where the intracrystalline diffusion in the nanotubes was the rate‐controlling process.