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通过定点聚合混合在小分子铁电液晶中的可交联单体来制备高聚合体网络稳定铁电液晶 (PNSFL Cs)。试验中所用单体为紫外固化光学粘合剂 NOA6 5 ,其用量少于 5 %。铁电液晶中存在很少量的聚合体网络可以引起相变行为的显著变化。聚合体网络的存在可减小分子倾斜角和降低液晶载体的自发极化强度。分子倾斜角和自发极化强度与温度的对应关系可用指数函数来描述。但在聚合体存在的情形下 ,函数参数的数值不同于在均场近似下由经典朗道理论所得到的数值。对于纯铁电液晶 ,自发极化强度与分子倾斜角之间存在与温度无关的线性关系 ;在聚合体网络存在的情形下 ,这一线性关系的温度独立性被破坏。
High polymer network-stabilized ferroelectric liquid crystal (PNSFL Cs) was prepared by site-directed polymerization of a cross-linkable monomer mixed in a small molecule ferroelectric liquid crystal. The monomer used in the experiment was UV-curable optical adhesive NOA6 5 in an amount of less than 5%. The presence of a small number of polymer networks in ferroelectric liquid crystals can cause significant changes in phase transition behavior. The existence of the polymer network can reduce the molecular tilt angle and reduce the spontaneous polarization of the liquid crystal carrier. The corresponding relationship between molecular tilt angle and spontaneous polarization intensity and temperature can be described by exponential function. However, in the presence of a polymer, the values of the function parameters are different from the values obtained by the classical Landau theory in a mean-field approximation. For pure ferroelectric liquid crystals, there is a linear temperature-independent relationship between spontaneous polarization and molecular tilt angle; in the presence of polymer networks, the temperature independence of this linear relationship is impaired.