CRITICAL DROPLETS ON A WALL NEAR A 1ST-ORDER WETTING TRANSITION

For critical droplets on a wall near a first-order wetting transition we discuss the crossover behavior from the partial wetting to the prewetting regime. The droplet shape changes smoothly from a spherical cap in the former to a flat cylinder in the latter regime. For sufficiently long-ranged molecular interactions the crossover behavior can be described by scaling forms which in a number of special cases reduce to results previously obtained by de Gennes and co-workers. van der Waals forces form a limiting case in which we recover logarithmic anomalies. For interactions of shorter range we present some mean-field results, although fluctuations might be important in this case.