Multiple interfaces in diffusional phase transitions in binary mesogen-non-mesogen mixtures undergoing metastable phase separation

EZEQUIEL R. SOULÉ; CYRILLE LAVIGNE; LINDA REVEN; ALEJANDRO D. REY

Mainz

Conferencia; 24th International Liquid Crystal Conference; 2012

Simultaneous chemical demixing and phase ordering for a mixed order parameter system is studied theoretically, in conditions where an isotropic-isotropic demixing is metastable with respect to the isotropic-nematic transition. The evolution of a nematic (N) domain in a supercooled isotropic (I) medium is simulated. Different dynamic regimes are found depending on the location of the initial conditions in the thermodynamic phase diagram as discussed below and shown schematically in figure 1.When the temperature is significantly higher than the critical co-disolution temperature (Tc), the typical diffusional process with a smooth depletion layer is observed. As Tc is approached from above, an inflection point is observed in the concentration profile in the depletion layer. When the temperature is lower than Tc, the concentration range that corresponds to I-I phase separation is comprised within the depletion layer. In this conditions, a I-I phase separation takes place in the depletion layer, producing a second interface.