Dipole-induced chiral smectic-C phase in a eutectic mixture of cholesterol esters

Abstract: Both cholesteryl oleate (CO) and cholesteryl oleyl carbonate (COC) are thermotropic mesogens with a general cooling phase sequence: isotropic→cholesteric→smectic→crystal. They are almost identical with respect to molecular structure and the central location of molecular dipole. However, the orientation of the latter is axial for CO and transverse for COC. A eutectic mixture of these components shows a phase sequence like the above but involving an induced smectic-C* phase. We explain this discovery on the basis of computer simulation results involving rigid core-dipole-flexible tail model of a mesogen and argue in favor of a ferroelectric liquid crystal model of the induced phase. [Copyright &y& Elsevier]