COMPUTER-SIMULATION IN PORES WITH RECTANGULAR CROSS-SECTIONS

Monte Carlo computer simulations are reported for the sorption of Ar a t 90 K in several pores of different shapes. In all cases, the pore wa lls were modeled as perfectly flat graphitic planes that have been ass embled to form pores with rectangular cross-sections characterized by having one dimension fixed at a value that allows four layers of argon in the full pore (with one exception). The second dimension of the re ctangle was varied from four to eight to 12 argon atom diameters to in finite (simple slit). A pore having dimensions of 7 x 7 argon atoms wa s also studied. It is shown that the presence of corners in these pore s has a profound effect upon their adsorptive behavior; that adsorptio n in the corners can be quantitatively treated in terms of one-dimensi onal theory; and that the remaining adsorption on the walls gives mono layer packings with liquid-like two-dimensional densities. The effect of pore shape upon capillary condensation and hysteresis is also inves tigated. (C) 1998 Elsevier Science Ltd. All rights reserved.