NUCLEATION AND GROWTH OF TIGHTLY PACKED DROPLETS IN FLUIDS

Experiments of phase separation have been performed in a density-match ed liquid mixture (partially deuterated cyclohexane-methanol at 1.4% b elow critical concentration) and in a pure fluid (SF6 at 3.6% above cr itical density). The usual strong gravity-induced flows that accompany phase separation in pure fluids are suppressed by performing experime nts under reduced gravity. Experiments under microgravity are compared with experiments on Earth. Phase separation under reduced gravity is characterized by a pattern of tightly packed droplets of the minority phase whose growth can be expressed over more than 7 decades in time b y a single reduced power law with exponent 1/3.