KINETICS OF THE INITIAL-STAGE OF ISOTHERMAL GAS-PHASE FORMATION

A theoretical description is proposed of the kinetics of the initial stage of gas phase formation in supersaturated liquids at constant temperature. General expressions are given for the time dependence of the number N of bubbles nucleated, of the probability P of appearance of at least one nucleus bubble and of the total volume V(g) of the newly formed gas phase in the case of progressive or instantaneous bubble nucleation. Different definitions of the critical supersaturation for gas phase formation are considered and their experimental applicability is discussed. The general results are applied to the particular cases of gas phase formation at constant and steadily declining pressure and the corresponding time dependence of N, P, and V(g) is obtained. Expressions for the critical supersaturation are also derived and it is found that this quantity can be rather sensitive to the rate of pressure decline when gas phase formation occurs via instantaneous bubble nucleation.