Grand Canonical Monte Carlo study of argon adsorption in aluminium nanopores

Abstract

We present a theoretical study of argon adsorption on a model aluminium substrate structured with cylindrical nanopores. We employ state-of-the-art computational methods to obtain (i) accurate three-dimensional adsorption potentials for the nanostructured substrate starting from the corresponding ab initio physisorption potential for a planar surface, and (ii) the adsorption and desorption isotherms by means of Grand Canonical Monte Carlo (GCMC) simulations. We study the effect of pore shapes upon argon adsorption in the case of a substrate characterized by a periodic arrangement of identical cylindrical nano-pores, open at both ends or with one end closed. We find the occurrence of hysteresis loops between adsorption and desorption cycles in open-end pores, in accordance to recent experiments and to previous theoretical approaches. At variance with the prediction of the empirical Cohan law, we also find hysteresis in pores with one closed end.

Keywords:

• adsorption
• nanopores
• fluid

Acknowledgments

We thank Giampaolo Mistura and Benoit Coasne for useful comments and discussions. We acknowledge the support of Padova University through project CPDA077281-07.