INTEGRAL-EQUATION THEORY FOR THE ADSORPTION OF CHAIN FLUIDS IN SLITLIKE PORES

The adsorption of hard chains in slitlike pores is studied via an integral equation theory. The theory uses the growing adsorbent model in conjunction with the polymer reference interaction site model (polymer-RISM) theory to predict the wall-fluid correlation functions; wall-fluid and fluid-fluid correlations are treated using the Percus-Yevick closure relations. The theory is compared to Monte Carlo simulation data for the density profiles of 4-mers and 8-mers in slitlike pores; the theory is fairly accurate, though it tends to overestimate the density at the wall at low densities and underestimate the density at the wall at high densities. The theory also underestimates the amplitude of the oscillations in the density profile. The theory is very accurate, however, for the adsorption isotherm of 4-mers and 8-mers.