Influence of a small amount of tethered chains on wetting transitions: A density functional approach

A density functional approach to adsorption and phase behavior of a simple fluid from gas phase on a surface modified with a small amount of grafted chains is presented. The chains are modeled as freely jointed tangent spheres with end segments attached to the surface. The segments and gas molecules interact via the Lennard–Jones potential. We have found that the presence of preadsorbed chains considerably affects wettability of solid surfaces. An increase in the amount of grafted chains leads to a crossover between prewetting and layering transitions. This crossover occurs by merging of successive layering transitions.