Roy D, Fragiadakis D, Roland C M, Dabrowski R, Dziaduszek J, Urban S
Naval Research Laboratory, Chemistry Division, Code 6120, Washington DC 20375-5342, USA.
Institute of Chemistry, Military University of Technology, 00-908 Warsaw, Poland.
J Chem Phys. 2014 Feb 21;140(7):074502. doi: 10.1063/1.4865413.
The synthesis, equation of state, phase diagram, and dielectric relaxation properties are reported for a new liquid crystal, 4(')-butyl-4-(2-methylbutoxy)azoxybenzene (4ABO5*), which exhibits a cholesteric phase at ambient temperature. The steepness of the intermolecular potential was characterized from the thermodynamic potential parameter, Γ = 4.3 ± 0.1 and the dynamic scaling exponent, γ = 3.5 ± 0.2. The difference between them is similar to that seen previously for nematic and smectic liquid crystals, with the near equivalence of Γ and γ consistent with the near constancy of the relaxation time of 4ABO5* at the cholesteric to isotropic phase transition (i.e., the clearing line). Thus, chirality does not cause deviations from the general relationship between thermodynamics and dynamics in the ordered phase of liquid crystals. The ionic conductivity of 4ABO5* shows strong coupling to the reorientational dynamics.
报道了一种新型液晶4(')-丁基-4-(2-甲基丁氧基)氧化偶氮苯(4ABO5*)的合成、状态方程、相图和介电弛豫特性，该液晶在室温下呈现胆甾相。通过热力学势参数Γ = 4.3 ± 0.1和动态标度指数γ = 3.5 ± 0.2表征了分子间势的陡度。它们之间的差异与之前向列相和近晶相液晶的情况相似，Γ和γ近乎相等，这与4ABO5在胆甾相到各向同性相转变(即清亮点线)时弛豫时间的近乎恒定一致。因此，手性不会导致液晶有序相中热力学与动力学之间的一般关系出现偏差。4ABO5的离子电导率与重取向动力学表现出强耦合。
