Defect and Nondefect Interstitial Channel Availability in Carbon Nanotube Bundles: Comparison of Modeling with Experiments

Abstract

There is a controversy in the literature over whether small gases, such as Ne, can adsorb in the interstitial channels (ICs) of carbon nanotube bundles. We distinguish between two types of ICs: nondefect, defined as ICs in perfectly packed arrays of nanotubes having all of the same diameter (homogeneous) defined where three tubes meet, and defect ICs, present in bundles composed of nanotubes having different diameters (heterogeneous) where four or more tubes meet. We have performed grand-canonical Monte Carlo simulations of Ne on various model carbon nanotube bundles in order to explore the role of nondefect and defect ICs in adsorption. We have performed simulations on closed and partially opened homogeneous and heterogeneous bundles. We have computed the specific surface area, the isosteric heats of adsorption, and adsorption isotherms from our simulations, and we have compared these values to experimentally measured quantities for Ne adsorption on carbon nanotubes produced by the HiPco process. Analysi...