Ebullition From Solid Surfaces in the Absence of a Pre-Existing Gaseous Phase

Abstract The nucleation theory of Volmer and Fisher is extended to the superheating of liquids in contact with various solid boundaries. It is shown that nucleation in the bulk phase, at flat surfaces, at sharp projections, or in wetted cavities can be dismissed from consideration as possible explanations for experimentally observed superheats. Unwetted cavities are preferred nucleation points; but the difficulties of filling these completely with liquid are so great that it is probable that nucleation almost always occurs at a pre-existing gaseous phase in static stressing of the liquid. Nucleation in dynamic-stress phenomena, such as ebullition, cavitation, or effervescence, always occurs at the boundaries of gas or vapor entrapped in surface cavities.