Weighted density functional theories of drying at solid–fluid interfaces: Clarification of recent controversies

The statistical mechanics of contact angle phenomena and wetting/drying transitions at wall–fluid interfaces has benefitted from a series of recent computer simulation studies and density functional treatments. Various groups have contributed to this effort and not all of the results published to date appear to be in agreement. In particular, seemingly conflicting reports of the nature of the drying transition at model wall–liquid interfaces has generated significant confusion. Our purpose here is to clarify the situation by (i) demonstrating full consistency between two weighted density functional studies of wall–fluid interfaces, previously thought to be in conflict, and by (ii) reporting on a new density functional analysis of an earlier controversy surrounding the measurement of contact angles by computer simulation procedures involving ‘‘live’’ walls.