Modeling Adsorption of Hydrogen-Bonded Molecules in Porous Structures

Abstract

Abstract : This report describes progress on a research project on using molecular modeling and simulation to understand the adsorption of water and other hydrogen bonded fluids in carbon materials. We describe progress on five research topics: i) We have developed a model for activated carbon adsorption. In this model the carbon is treated as a collection of randomly oriented platelets representing the graphene planes in carbon; ii) We have used this to study the adsorption of water in activated carbon. The model correctly describes behavior measured experimentally, including the temperature dependence of hysteresis loops; iii) We have made a study of adsorption of water in slit shaped model pores to investigate the question of whether water can condense in pores without there being specific interactions with active sites; iv) As a first step in extending our work to the treatment of adsorption of mixtures of water and organic molecules in activated carbon we have made a study of mixtures of ethane and methane in activated carbon and compared our predictions with experiment; v) We have developed a lattice model for water adsorption in porous materials. We have made Monte Carlo simulations of water adsorption in both a carbon slit pore and a coarse-grained activated carbon structure using this model.