Homogeneous nucleation of droplets and interfacial tension in the liquid system methanol-water-tribromomethane

Abstract

Unstable homogeneous solutions within the miscibility gap of the ternary liquid system methanol-water-tribromomethane were made by rapid mixing of stable solutions. Characteristic times (induction periods) for the appearance of turbidity were measured at 25 °C. These induction periods are of the order 0.1 to 10 ms, depending on the composition of the unstable solution. For induction periods shorter than about 1 ms the measured data can be explained by assuming homogeneous nucleation of droplets followed by diffusion controlled growth. The ration between the interfacial tension calculated from the nucleation data and the bulk interfacial tension determined by the classical drop weight method is less than one, and approaches unity when the composition of the unstable system approaches the critical composition, i.e., when the interfacial tension approaches zero, and the critical nuclei become infinitely large.