Light-scattering-mode optical switching and image storage in polymer/liquid crystal composite films by means of photochemical phase transition
Light-scattering-mode optical switching and image storage in polymer/liquid crystal composite films by means of photochemical phase transition
复制标题
DOI：
10.1016/s0032-3861(99)00357-2
复制
发表时间：
2000-03
期刊：
影响因子：
4.6
通讯作者：
H. Lee;Keina Doi;A. Kanazawa;T. Shiono;T. Ikeda;T. Fujisawa;M. Aizawa;B. Lee
中科院分区：
文献类型：
--
作者：
H. Lee;Keina Doi;A. Kanazawa;T. Shiono;T. Ikeda;T. Fujisawa;M. Aizawa;B. Lee
研究了表面带有烷基侧链的各向同性(I)丙烯酸酯聚合物中客体偶氮苯光异构化引发的向列型(N)液晶(LC)聚合物的光化学相变行为。这些聚合物/液晶复合膜是由含有双官能团的丙烯酸酯单体和单官能团的丙烯酸酯单体通过原位热聚合诱导相分离的方法制备的。通过反式顺式光致异构化诱导聚合物基质中液晶区的光化学N-I相变，本征复合薄膜的强光散射态转变为完全透明的状态。从透明态恢复到初始光散射态的过程受烷基侧链的强烈影响。而短烷基侧链复合薄膜由于可以在两种不同的光学状态之间实现可逆的、重复的光开关，可以作为一种全光开关材料，而长烷基侧链复合薄膜则表现出基于光散射模式的高对比度光学图像存储能力。
Photochemical phase transition behavior triggered by photoisomerization of a guest azobenzene doped in nematic (N) liquid-crystalline (LC) domains was investigated in isotropic (I) acrylate polymers with alkyl side chains on their surfaces. These polymer/LC composite films were prepared by in situ thermal polymerization-induced phase separation method (thermal PIPS) from their starting mixtures containing a di- and a mono-functional acrylate monomer. Strong light-scattering states of the intrinsic composite films were transformed into complete transparent states by photochemical N–I phase transition of the LC domains within the polymer matrices that was induced by the trans–cis photoisomerization. Recovery process from the transparent state to the initial light-scattering state was strongly influenced by the alkyl side chains. While the composite film with short alkyl side chain acted as an all-optical switching material because the optical switching could be achieved reversibly and repeatedly between the two different optical states, the composite films with long alkyl side chain showed an ability of optical image storage with high contrast based on light-scattering mode.