Early Stage Kinetics of Phase-Separating Liquid Mixtures

Abstract

Observation of the very early stage of phase separation is made difficult by the large number of nucleated domains and the polydispersity of the droplet distribution. We investigate this issue using laser waves to locally quench a liquid mixture with two intersecting pump beams whose interference pattern traps the nuclei on the fringes. The time-resolved reflectivity of a third probe wave on the induced droplet grating (i) confirms that nucleation is heterogeneous even in the bulk, and (ii) surprisingly shows that impurities lead to an unexpected reduction of the growth onto a single ``medium-dependent master curve'' when samples are synthesized with the same lots of constituents.