DENSITY PROFILES OF A DOUBLE SQUARE-WELL MODEL OF A CHEMICALLY ASSOCIATING FLUID NEAR A HARD-WALL

Density profiles of a double square-well model of a chemically associa ting fluid near a hard wall are studied using integral equations and c omputer simulation techniques. The model of the bulk fluid is a two-co mponent system of 'hard' spheres which, if of different species, are a ble to overlap and form dimers. This kind of transformation represents a chemical reaction between monomeric units and is generated by an in terparticle interaction in the form of an intracore attractive double square well. The dimers which consist of the same species, but differ in the bonding length, are treated as isomers of the product of the re action of dimerization. Peculiarities in the behaviour of the bulk flu id influence the density profiles and the absorption of particles at a hard wall. The effects of chemical reaction, the bulk density, and en ergetic characteristics of each of the attractive wells on the density profiles are investigated. The theory is compared with Monte Carlo co mputer simulation data.