Notizen: Specific Volume Studies on Some Nematic Liquid Crystals

The temperature variation of the specific volume of two nematic liquid crystals (HBT and OBT) has been observed in both the nematic and isotropic regions. A sudden jump is observed in the vicinity of the nematic-isotropic transition indicating a first order phase transition. Pretransitional effects are found to occur only on the nematic side of the transition. This accords with the Maier-Saupe theory. Some parameters such as S , A, the adiabatic compressibility, the Rao number, and the van der Waals constant are also determined.