Phase-Transition Studies in Polimesomorphic Compounds. 1. Density Studies in N-(p-n-Hexyloxybenzylidene)-p-n-butylaniline

Article abstract of DOI:10.1021/j100228a040

The density, ρ, of N-(p-n-hexyloxybenzylidene)-p-n-butylaniline (HBBA) is measured as a function of temperature from the isotropic liquid to the smectic-G phase.The compound is tetramorphic exhibiting three smectic phases S_G, S_B, S_A and a nematic phase.The changes in density across the phase transformations, and the calculated thermal expansion coefficients, confirm the order of the transitions as first order.The particular importance of the smectic-A to nematic transformation, which is of first order, is apparent from the density jump across the transition.