Chemical Physics Interdisciplinary Program, Liquid Crystal Institute, Kent State University, Kent, Ohio 44242, USA.
Soft Matter. 2015 Feb 14;11(6):1208-13. doi: 10.1039/c4sm02283a.
We experimentally observed that the photonic band gap (reflection band) of polymer stabilized cholesteric liquid crystals with negative dielectric anisotropies can be greatly broadened under DC electric fields. We explored the underlying mechanism. We found that the dispersed polymer network moved when DC voltages were applied across the liquid crystal cell. The motion of the polymer network stretched the helical pitch of the liquid crystal on one side of the cell and compressed the helical pitch on the other side of the cell. We proposed a phenomenological theory to explain the motion of the polymer network and the effect of the polymer network on the helical pitch, and this theoretical prediction agreed well with the experimental results.
我们实验观察到，具有负介电各向异性的聚合物稳定胆甾相液晶的光子带隙（反射带）可以在直流电场下大大展宽。我们探讨了其内在机制。我们发现，当在液晶盒上施加直流电压时，分散的聚合物网络会发生移动。聚合物网络的运动拉伸了盒一侧的液晶螺旋间距，压缩了盒另一侧的液晶螺旋间距。我们提出了一个唯象理论来解释聚合物网络的运动以及聚合物网络对螺旋间距的影响，该理论预测与实验结果吻合良好。
