摘要
本文用晶格模型研究球形小分子作为溶质对液晶相变(N-I相变)性质的影响。计算结果表明,当溶质分子与液晶溶剂分子之间作用力较弱时,相变温度随浓度的增加而降低;而当溶质分子与液晶溶剂分子之间作用力较强时,相变温度随浓度的增加而增加。也用此模型计算了小分子溶质溶于液晶溶剂时溶质的无限稀活度系数,并与运用气相色谱法测得的硝基甲苯异构体溶于液晶PBH_xB(H_(13)C_6O-C_6H_4-COO-C_6H_4-OOC-C_6H_4-OC_6H_(13))的实验结果进行了比较,对溶质与溶剂分子之间作用力的状况得到了有益的启示。
Lattice model is appied to study the transition properties of liquid crystal under the influence of small spherical molecules as solutes. It is found that the transition temperature decreases if the interaction between molecules of solute and mesomorphic solvent is weak and increases for strong interaction with the increasing of solute concentration.This model is also apllied to study the activity coefficient of non-mesogenic molecules as solute solved in liquid crystal. The theoretical results are compared with the data determined by gas chromatography experiments. In these experiments, the liquid crystal PBH_xB was used to separate three isomers m-,o-,p-nitrotoluence, and the activity coefficients. of the three isomers were determined at various temperatures. It is found that, in the considered region, larger potential between solute and solvent molecules corresponding to the larger activity coefficient and decreasing faster with increasing temperature.
基金
国家自然科学基金资助项目
