Capillary condensation of water in nanopores: is there a relation between hydrophobicity, absorption pressures and hysteresis?

MATIAS FACTOROVICH; VALERIA MOLINERO; DAMIAN A. SCHERLIS

Holderness School in Plymouth, New Hampshire

Congreso; Water & Aqueous Solutions GRC; 2012

Gordon Research Conferences

We focus on the implementation and application of Grand Canonical Molecular Dynamics simulations in Nanoporous materials, to analyze the adsorption isotherms and the hysteresis commonly seen in these systems. We have validated our approach against Monte-Carlo results for Lennard-Jones fluids in slit pores. To perform these simulations, the critical parameter to be adjusted is the ratio between Monte Carlo and Molecular Dynamics steps, in order to obtain the time-dependent properties of the system (Molecular Dynamics), without loosing the Grand Canonical properties (Monte Carlo). In particular, we present how such ratio influences the outcome of the simulations, and the resulting isotherm for the optimized ratio. Moreover, we show results of the behavior of water in nanopores of different geometries and hydrophilicities, with an emphasis in the role of these features in the hysteresis loop.