Texture and surface sites of treated and as-prepared SWNT using experimental and simulation methods

Surface properties of single wall carbon nanotubes (SWNT) subjected to different treatments were studied. Nitrogen, argon and carbon dioxide were used to study the adsorption properties and its influence by the presence of surface sites on SWNT, acid treated SWNT and heat treated SWNT. Special attention was paid to carbon dioxide adsorption, by means of adsorption microcalorimetry and Monte Carlo simulation considering the presence of surface oxygen groups. Monte Carlo simulation showed that these surface groups affect the adsorption properties of oxidized SWNT and their corresponding enthalpies of adsorption. The SWNT model systems, with open or closed nanotubes and with or without oxygen in their walls, showed agreement with the experimental enthalpies of adsorption. Thereby, Monte Carlo simulation and experimental enthalpies of adsorption are suggested as an adequate method of characterization of SWNT adsorption sites.