The Generation of Three-dimensional Anisotropies in Thin Polymer Films by Angular Selective Photoproduct Formation and Annealing
The Generation of Three-dimensional Anisotropies in Thin Polymer Films by Angular Selective Photoproduct Formation and Annealing
复制标题
通过角度选择性光产物形成和退火在聚合物薄膜中产生三维各向异性
DOI：
10.1021/ma0476846
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发表时间：
2005
期刊：
影响因子：
5.5
通讯作者：
J. Stumpe
中科院分区：
文献类型：
--
作者：
C. C. Jung;R. Rosenhauer;M. Rutloh;Christian Kempe;J. Stumpe
线偏振光可以在含有不同光致变色基团的聚合物薄膜中诱导出与光的偏振方向平行的有序。原则上，这提供了在聚合物薄膜中产生延长的面内有序的可能性。本文研究了两个这样的光化学过程。其中一种是在非偏振紫外预照射步骤后，用线偏振红光照射含偶氮苯的聚合物薄膜。另一种是线偏振紫外光诱导的肉桂酸酯类聚合物薄膜的角度选择性光环加成反应。由于在这两种情况下，辐照后的有序度都很低，液晶聚合物薄膜在其中间相进行了热处理，以通过热致自组织来改变光诱导有序性。根据聚合物的结构、制备条件和辐照条件的不同，由波导谱测定得到的三维指示物是平面拉长的、双轴的或同向的。
Linearly polarized light can induce an order parallel to the polarization direction of light in polymer films containing different photochromic groups. In principle, this offers the possibility to generate prolate in-plane orders in polymer films. Two such photochemical processes are investigated in this paper. One of them is the irradiation of azobenzene-containing polymer films with linearly polarized red light after an unpolarized UV preirradiation step. The other one is the angular selective photocycloaddition of cinnamate-containing polymer films induced by linearly polarized UV light. Because in both cases the order is low after the irradiation, the liquid crystalline polymer films are annealed in their mesophase to modify the photoinduced order by thermotropic self-organization. The resulting three-dimensional indicatrices, as determined by waveguide spectroscopy, are found to be prolate in-plane, biaxial, or homeotropic in dependence on the polymer structures, preparation conditions, and irradiati...