Pressure Dependence of the Nematic-to-Isotropic Transition in the Lyotropic Liquid Crystal Cesium Perfluoro-Octanoate

We report light-scattering measurements under pressures up to 1000 bars of nematic short-range order in the isotropic phase of the lyotropic liquid-crystal system cesium perfluoro-octanoate and water. The nematic-to-isotropic transition temperature is a nonlinear function of pressure which changes strongly with concentration and $\frac{d{T}_{\mathrm{NI}}}{\mathrm{dp}}$ is from 10 to 100 times smaller than in typical thermotropic nematics. We also find the bare correlation length in the isotropic phase to be 12.5 ± 2 Å.