Pressure discotics

Bates M A and Luckhurst G R 1996 Computer simulation studies of anisotropic systems. 26. Monte Carlo investigations of a Gay-Berne discotic at constant pressure J. Chem. Phys. 104 6696-709... 

Figure 12. Orientational dynamics of the discotic system GBDII (N = 500) at several temperatures across the isotropic-nematic transition along the isobar at pressure P — 25. (a) Time evolution of the single-particle second-rank orientational time correlation function in a log-log plot. Temperature decreases from left to right, (b) Time dependence the OKE signal at short-to-intermediate times in a log-log plot. Temperature decreases from top to bottom on the left side of the plot T = 2.991,2.693,2.646, and 2.594. The dashed lines are the simulation data and the continuous lines are the linear fits to the data, showing the power law decay regimes at temperatures. (Reproduced from Ref. 115.)...

When a different isobar was chosen at a lower pressure for the discotic system, a direct transition from the isotropic phase to the columnar phase was observed [119]. In this case, decay of neither the single-particle second-rank OTCF nor the OKE signal showed any power law regime [119]. As compared... 

This Datareview has concentrated on the nematic-isotropic transition except for the case of the truxenes where the discotic nematic to a columnar phase was considered. No smectic or crystal phase data have been considered here even though the literature reviewed often contained pressure-temperature data involving these phases. Data for the crystal-nematic transition are almost always included in the studies, but only sometimes even when the compound exhibits a smectic phase are such data included. No surprises exist in the body of pressure-temperature data for the nematic-isotropic transition. This transition for any nematogen could be described by the polynomial fitting equation with surprisingly small uncertainties in the average fitting parameters for example... 

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