Theory of Liquid Crystalline Phases in Amphiphilic Systems

Abstract

A variety of amphiphilic molecules reversibly aggregate to form polydisperse asymmetric particles that spontaneously align at sufficiently high concentrations. Such system have been modeled using a lattice description of excluded volume effects and a phenomenological description of aggregate assembly. Our earlier calculations restricted to the formation of rod-like aggregates, have now been extended to include the formation of plate-like aggregates. Thus two types of aligned phases are possible: axial, in which the averagelength of particle edges parallel to the director is greater than perpendicular to the director, and planar, in which the opposite occurs. When rod and plate growth are equally favored the calculated phasediagram displays a sequence of first order transitions from isotropic to axial to planar phases. Additional sequences of phase transitions calculated from this model are reported.