梳型高分子聚合物液晶的相变

Phase Transition of Comb Polymer Liquid Crystal

利用Freiser关于液晶分子相互作用模型,建立了梳型高聚物分子的哈密顿量,适用变分程序导出高聚物液晶结合相序参数自洽方程,得到在给定分子结构参数时的各向同性相至单轴向列相以及单轴至双轴向列相的相变。结果表明,当分子主、侧链间隔基团的耦合项中排斥作用以及结合相中较强向列相场者强度增大时,单轴至双轴向列相相变温度升高,并从一级相变逐渐变为二级相变。

The Hamiltonian of comb polymer molecule is set up by using interaction model of liquid crystal proposed by Freiser. The order parnameter self-consistency equations of combined phase of polymer liquid crystal are derived by derivation procedure. The phase transition from isotropic to uniaxial nematics and from uniaxial to biaxial nematies are obtained for given molecular structure. The results show that when the repulsion in coupling term of main chain and side chain, the magnetude of strong nematic field of combined phase increase, the phase transition temperature from uniaxial to biaxial will rise and gradually changes from first order to second order phase transition.