Conditions for stability of bubble nuclei in solid surfaces contacting a liquid-gas solution

Abstract

We first consider the conditions under which pockets of a gaseous phase, i.e., bubble nuclei, would be in stable equilibrium in the roughness of the walls of a container of liquid-gas solution or in the walls of small, solid particles suspended in the liquid phase. It is shown that if there are a sufficient number of such nuclei, then in an arbitrarily large, closed volume of solution maintained at constant temperature and pressure, these tiny bubble nuclei can be in a thermodynamically stable equilibrium state when the gas concentration in the liquid phase is only slightly greater than the equilibrium value and the contact angle is small. The conditions under which these bubble nuclei result in the appearance of macroscopic bubbles is then considered. It is shown that small superheats would result in macroscopic bubble appearance in such a system. Physically, the stable equilibrium state of the bubble nuclei results from the mutual competition of the bubble nuclei for the dissolved gas of the liquid phase.