Author(s): Holyst, R and Staniszewski, K and Patkowski, A and Gapinski, J
Title: Hidden minima of the Gibbs free energy revealed in a phase separation in polymer/surfactant/water mixture
Abstract: We observed a very unusual kinetic pathway in a separating C12E6/PEG/H2O mixture. We let the mixture separate above the spinodal (cloud point temperature) for some time and next cool it a metastable region of a phase diagram, characterized by two minima the Gibbs potential, one corresponding to the homogeneous mixture and to the fully separated PEG-rich and C12E6-rich phases. Despite the that in the metastable region the thermodynamic equilibrium to the separated phases (global minimum of the Gibbs free we observe perfect mixing of the initially separated phase. The state, obtained in this way, does not separate, if left However, many cooling-heating cycles or full separation visible meniscus above the cloud point temperature induce the phase in the metastable region. The metastable region can exist of degrees below the cloud point temperature. This effect is not observed in the binary mixture Of C12E6/H2O.
Pages: 8533-8537
Journal: JOURNAL OF PHYSICAL CHEMISTRY B
Volume: 109
ID: ISI:000228982900001
Year: 2005
DOI: 10.1021/jp050634y