Mechanism of Dropwise Condensation

Abstract

From a study of surface phenomena, information is obtained about conditions under which net condensation can occur. An experimental examination of the surface, using an optical method capable of detecting thin films of molecular dimensions, shows that no film greater than a monolayer in thickness exists on the area between the drops. Wetted pits and grooves in the surface are considered to be the most probable drop nucleation sites. A model for drop growth gives results which are compatible with experimentally observed values, and which show the growth rate to be a function of the vapor pressure.