A molecular theory including hard rod interactions of liquid crystalline phases exhibited by highly polar compounds

Abstract

We extend our molecular mean field model of highly polar compounds to include hard rod interactions to develop a hybrid model. The latter interactions are restricted to second virial terms, following a method developed by Koda and Kimura. This allows us to calculate pressure-temperature phase diagrams. Depending on the model parameters used, the phase diagrams exhibit the following features: nematic-nematic phase transition, bounded SmAd region, double reentrance, reentrant nematic lake surrounded by the smectic A phase (the reentrant nematic lake merging with the main nematic sea) as well as the possibility of quadruple reentrance. We compare the calculated phase diagrams with the available experimental data.