Title: ADSORPTION OF HARD SPHERE FLUID IN POROUS MATERIAL: A MONTE CARLO SIMULATION APPROACH FOR PRESSURE CALCULATION
Author(s): P.Orea (Instituto Mexicano del Petr{\'{o}}leo, Programa de Ingenier{\'}ia Molecular, 07730, D.F., M{\'{e}}xico) , Yu.Duda (Instituto Mexicano del Petr{\'{o}}leo, Programa de Ingenier{\'}ia Molecular, 07730, D.F., M{\'{e}}xico; Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine, 1 Svientsitskii Str., 79011 Lviv, Ukraine)

We have performed Monte Carlo simulations in the canonical ensemble of a hard-sphere fluid adsorbed in microporous media. The pressure of the adsorbed fluid is calculated by using an original procedure that includes the calculations of the pressure tensor components during the simulation. In order to confirm the equivalence of bulk and adsorbed fluid pressures, we have exploited the mechanical condition of equilibrium and performed additional canonical Monte Carlo simulations in a super system ``bulk fluid + adsorbed fluid''. When the configuration of a model porous media permits each of its particles to be in contact with adsorbed fluid particles, we found that these pressures are equal. Unlike the grand canonical Monte Carlo method, the proposed calculation approach can be used efficiently to obtain adsorption isotherms over a wide range of fluid densities and porosities of adsorbent.

Key words: adsorption, porous material, pressure, simulation
PACS: 05.20.Jj, 61.25.Em