Brillouin scattering investigation of ME6N liquid crystal in CCl4

Some experimental Brillouin scattering measurements have been performed on binary mixtures composed of a liquid crystal immersed in a non-polar solvent. The experimental compressibility has been fitted using a theoretical approach based on a hard-core model whose reliability has been successfully checked for many binary mixtures of molecular liquids. In this article we generalize this apparently naïve approach to the case where the molecular shape of one of the two involved species is elongated. The agreement with experimental results seems to support our leading idea that the compressibility behaviour is mainly driven by excluded volume interactions.