High-pressure volumetric measurements near a smectic-nematic-isotropic triple point

Thermodynamical scaling of the low frequency relaxation time in liquid crystalline phases

The low frequency relaxation times tau//, which characterize the flip-flop molecular motions in liquid crystalline phases, recently determined in high-pressure experiments for eight liquid crystalline substances, were reanalyzed considering a relation proposed for the glass-forming liquids [C. Dreyfus, Phys. Rev. E 68, 011204 (2003); R. Casalini and C. M. Roland, Phys. Rev. E 69, 062501 (2004)]. The data, measured at constant pressure, constant temperature, and constant molar volume, could be rescaled onto a master line in the ln tau// vs 1/(T V(gamma)m) plot, with gamma as an adjustable parameter (Vm=1/rho is the specific volume). The obtained gamma values are in good agreement with other estimations; here, the value of gamma parameter was determined for the crystal-like smectic- E phase.