ASSOCIATING LATTICE FLUIDS NEAR HARD AND INTERACTING WALLS

Cubic lattice models of dimerizing and polymerizing fluids have been s tudied within Wertheim's Ornstein-Zernike (OZ) matrix formalism to ass ess the adsorption behavior of such fluids at impenetrable, interactin g walls. The OZ matrix formalism is relatively easy-to-handle for thes e cubic lattice models, due to the absence of liquid-like packing effe cts. The calculated concentration profiles have been compared to NVT-M onte Carlo simulations. The simulation of the polymerizing fluid emplo yed a biased cluster move, based on the configurational bias scheme of Siepmann and Frenkel. The dimerizing fluid profiles are in nearly qua ntitative agreement with the simulation results, even for a fully asso ciated, i.e., dimeric fluid. This is in contrast with the polymerizing fluid profiles that show important deviations from the simulation res ults, especially near interacting walls. It is therefore concluded tha t better approximations are needed in solving Wertheim's OZ matrix for the polymerizing fluid.