Studies on nucleation phenomena occurring in aqueous solutions supersaturated with calcium sulfate. II. The induction time

Abstract

The results of a set of experiments designed to delineate the effects of changes in temperature and supersaturation levels on the length of the time interval between establishing those levels and the detection of a steady-state nucleation rate of CaSO4•2H2O from solution are reported. The data were obtained using the droplet technique coupled with insitu generation of SO42− at such a rate that the system experienced a near step function change in the driving force with time. A theoretical model for the length of the time interval is derived and compared with the data. Empirical modeling studies led to a rather different functional relationship that is compared with a theoretical model discussed in the literature by Frisch and Carlier. The functional form of an equation relating together the lag time and the subsequent nucleation rate exhibited by a given system is proposed.