Volume phase transitions of smectic liquid crystalline gels

我们提出了一个平均场理论来描述侧链液晶凝胶的体积相变，伴随着各向同性-向列相-近晶A相变。利用取向有序参数和平移有序参数定义了三种不同的单轴向列相和近晶A相。我们发现，液晶凝胶在各向同性-向列相、等位相-近晶相A和向列相-近晶相A相变时发生了不连续的体积变化。主链和介晶侧基的构象对于理解液晶凝胶的溶胀行为是很重要的。我们希望这些结果能鼓励对液晶凝胶的进一步实验研究。

We present a mean field theory to describe volume phase transitions of side-chain liquid crystalline gels, accompanied by isotropic-nematic-smectic A phase transitions. Three different uniaxial nematic phases and smectic A phases are defined by using orientational order parameters and translational order parameters. We find that the liquid crystalline gel discontinuously changes the volume at an isotropic-nematic, an isoropic-smectic A, and a nematic-smectic A phase transition. The conformation of backbone chains and mesogenic side groups are important to understand the swelling behaviors of liquid crystalline gels. We hope that these results encourage further experimental studies of the liquid crystalline gels.