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DY: Dynamik und Statistische Physik

DY 46: Poster

DY 46.56: Poster

Donnerstag, 30. März 2006, 16:00–18:00, P1

Adsorption isotherms and isosteric heat of monoatomic gas adsorbed on closed-end single-wall carbon nano-bundles — •Igor Poltavsky, Tatiana Antsygina, and Konstantin Chishko — B. Verkin Institute for Low Temperature Physics and Engineering, 47 Lenin Ave., Kharkov 61103, Ukraine

Adsorption isotherms and isosteric heats of monoatomic gas adsorbed on outer and inner surfaces of closed-end single-wall carbon nanotube bundles have been investigated theoretically. An original model to describe such a system was developed. The used approach is based on account of equilibrium conditions among three subsystems: a quasi-one-dimensional (so called "three-chain") subsystem formed by atoms in grooves on the outer surface, a two-dimensional (2D) monolayer on the outer surface and a one-dimensional subsystem formed by atoms adsorbed in interstitial channels. To describe the three-chain subsystem we took into account interactions between the nearest and second nearest neighbors in all three chains. Since we are interested in the coverage range where the formation of the monolayer just begins we treated the 2D subsystem as an ideal gas.

The adsorption isotherms and isosteric heat were calculated for different values of substrate binding energies and interparticle interaction parameters. Theoretical results are in good agreement with the experimental data. For real systems (helium and methane) we obtained the binding energies for adsorption in various positions. We also found the coverage ranges for which the adsorption into one of the above-mentioned subsystems prevails.