Ma RQ, Yang DK
Liquid Crystal Institute and Chemical Physics Program, Kent State University, Kent, Ohio 44242, USA.
Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics. 2000 Feb;61(2):1567-73. doi: 10.1103/physreve.61.1567.
We have constructed polymer-stabilized nematic liquid crystals by photopolymerizing diacrylate monomers in the nematic phase. The orientation of the liquid crystal was controlled by the polymer network. We studied the Freedericksz transition in these systems. Experimentally we studied the transition by measuring the capacitance of the liquid crystal cells as a function of applied voltage. The transition was affected profoundly by the dispersed polymer network. The threshold was higher with shorter interpolymer network distance. Theoretically we studied the systems using a two-dimensional model in which the polymer networks were represented by parallel cylinders with random location. The interaction between the liquid crystal and the polymer network was described by the boundary condition imposed by the polymer network. By fitting the experimental data, we found that the polymer cylinders had diameters of a few submicrons, and a substantial amount of liquid crystal was trapped inside the cylinders.
我们通过在向列相中将二丙烯酸酯单体光聚合，构建了聚合物稳定的向列型液晶。液晶的取向由聚合物网络控制。我们研究了这些体系中的弗雷德里克兹转变。实验上，我们通过测量液晶盒的电容作为外加电压的函数来研究该转变。该转变受到分散的聚合物网络的深刻影响。聚合物网络间距越短，阈值越高。理论上，我们使用二维模型研究这些体系，其中聚合物网络由位置随机的平行圆柱表示。液晶与聚合物网络之间的相互作用通过聚合物网络施加的边界条件来描述。通过拟合实验数据，我们发现聚合物圆柱的直径为几亚微米，并且大量液晶被困在圆柱内部。
