Phase transition studies in p-n-nonyloxybenzoic acid

Abstract Phase transitions of the liquid crystal p-n-nonyloxybenzoic acid have been investigated with density and ultrasonic velocity measurements. The variation of density with temperature confirms that the isotropic-nematic and nematic-smectic C transitions are of first order. All the phase transitions are confirmed by the variation of ultrasonic velocity with temperature. The adiabatic compressibility (βad), and Rao number (Rn) are also estimated.