adsorption; Lennard-Jones gas; wetting; rough surface; hard spheres; matrix spheres
We study the adsorption, including wetting, of a Lennard-Jones gas on a rough surface consisting of rough layer on a smooth substrate with which the gas interacts via a 9-3 potential. The rough layer is two molecular diameters thick and consists of a disordered quenched matrix of hard spheres. As well as interacting with the other matrix spheres by the hard-sphere potential, the matrix molecules interact with the gas molecules by the hard-sphere potential. Hence, on average, the degree to which the gas molecules can approach the substrate depends only on the density of the matrix layer. The density of this rough layer has a significant effect. As the density of the matrix layer increases, the adsorption isotherms pass from wetting to a prewetting transition, and, if the layer is dense enough, to partial wetting. It is interesting that the prewetting transition remains first order.
(c) 1999 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in The Journal of Chemical Physics and may be found at http://link.aip.org/link/?JCPSA6/110/15/1;