Phase separation in PVME-H₂O transparent system

The spinodal decomposition and the nucleation process were in-situ observed in two immiscible solutions, H₂O-7wt%PVME and H₂O- 3wt%PVME, and the influence of their different kinetics effects on the phase separation was examined. It was found that to form the same size minority phase droplets, the time in the nucleation process was 3∼4 times longer than that in spinodal decomposition. Moreover, since the phase separation was controlled by spinodal decomposition near the critical composition and there was the largest immiscible temperature interval, the phase migration of the minority phase had enough time. In addition, the Marangoni migration velocity was measured in H₂O-3wt%PVME solution, which agrees well with the theoretical values, suggesting that the Marangoni convection plays a key role during phase separation.