(629f) An Improved Classical Density Functional Theory for the Description of Adsorption Thermodynamics

Authors: 
Hlushak, S., Vanderbilt University
McCabe, C., Vanderbilt University
Cummings, P. T., Vanderbilt University



An improved classical density functional theory [1] (CDFT) based on the accurate bulk thermodynamics predicted by the first-order mean-spherical approximation (FMSA) [2] is applied to study the thermodynamics of adsorption of simple gases into porous materials.  
The CDTF theory is implemented in multiple dimensions, which allows studies of various confinement geometries, and makes use of Fast Fourier Transform to integrate the convolution integrals appearing during the calculation of the weighted densities. Contributions from the attractive interactions are taken into account using accurate structural properties [3,4,5] and energy-route thermodynamics obtained using the FMSA theory enhanced with the simplified exponential approximation [6,7,8]. The introduced improvements allow us to quickly and accurately calculate isotherms and heats of adsorption.
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[8]  S. Hlushak, P. Hlushak, A. Trokhymchuk, J. Chem. Phys., 138, 164107 (2013).