DIMPLE AND NOSE COALESCENCES IN PHASE-SEPARATION PROCESSES

Coalescence processes are investigated during phase separation in a de nsity-matched liquid mixture (partially deuterated cyclohexane and met hanol) under near-critical conditions. As a result of the interplay be tween capillary and lubrication forces, ''nose'' coalescence appears t o be always associated with the slow growth of isolated droplets (expo nent almost-equal-to 1/3), whereas ''dimple'' coalescence corresponds to the fast growth of interconnected droplets (exponent almost-equal-t o 1). At each stage of growth, the distribution of droplets trapped du ring dimple coalescence is reminiscent of all of the previous coalesce nce events.