Manipulation of the ferroelectricity in LC polymers via photomechanical isomerization of azobenzene moieties
Manipulation of the ferroelectricity in LC polymers via photomechanical isomerization of azobenzene moieties
复制标题
通过偶氮苯部分的光机械异构化控制液晶聚合物中的铁电性
DOI：
10.1002/macp.1996.021970602
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发表时间：
1996
影响因子：
2.5
通讯作者：
R. Zentel
中科院分区：
文献类型：
--
作者：
Tanja Öge;R. Zentel
我们报道了一种含有光致异构化发色团和非光致异构化介晶单元的新型铁电液晶侧链共聚物的合成和表征。在用紫外光照射时，与暗状态相比，自发偏振 (Ps) 显着下降，表明极性顺序受到抑制。我们将此解释为相序被发色团的顺式异构体破坏。用可见光照射后，仅恢复 Ps 的主要部分。光化学顺反异构化（相的恢复）导致与材料的暗态不同的稳态。据观察，液晶相中的热重异构化（顺反）比溶液中快一个数量级。
We report the synthesis and characterization of a new ferroelectric liquid crystalline side chain copolymer containing photoisomerizable chromophores and non-photoisomerizable mesogenic units. On illumination with UV-light a suppression of the polar order is obtained as indicated by a substantial drop of the spontaneous polarization (Ps) compared to the dark state. We interpret this as the phase order being disrupted by the cis-isomer of the chromophore. After illumination with VIS-light only the major part of Ps is restored. The photochemical cis-trans back-isomerization (restoration of the phase) leads to a different stationary state than the dark state of the material. The thermal reisomerization (cis-trans) in the liquid-crystalline phase was observed to be faster than in solution by one order of magnitude.