Anomalous Phase Separation Behavior in a Binary Mixture of Poly(vinyl methyl ether) and Water Under Deep Quench Conditions

Abstract

Generally, the dynamics and morphology of phase separation strongly depends on the quenching conditions¹. From this standpoint, phase separation phenomena are generally divided into nucleation-growth (NG) and spinodal decomposition (SD). In the unstable region, decomposition (a coarse graining process) usually proceeds faster with an increase in the quenching depth because the thermodynamic driving force for phase separation becomes larger. Here we report an anomalous, local phase-separation behavior which seems not to belong to the conventional categories described above. This phase separation is unusual because it does not accompany a coarse graining process after the formation of droplets. It has been observed in a binary mixture of poly(vinyl methyl ether)(PVME) and water at deep-level quenching conditions near the critical composition². A digital image analysis (DIA)^3–7 has been used for the quantitative study.