Photoinduced Deformation of Rigid Azobenzene-Containing Polymer Networks
Photoinduced Deformation of Rigid Azobenzene-Containing Polymer Networks
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DOI：
10.1021/ma302157u
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发表时间：
2013-01
期刊：
影响因子：
5.5
通讯作者：
Nobuhiko Hosono;M. Yoshikawa;H. Furukawa;Kenro Totani;Kyoko Yamada;Toshiyuki Watanabe;K. Horie
中科院分区：
文献类型：
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作者：
Nobuhiko Hosono;M. Yoshikawa;H. Furukawa;Kenro Totani;Kyoko Yamada;Toshiyuki Watanabe;K. Horie
合成了刚性芳香骨架中含有多个偶氮苯单元的光响应性聚（酰胺酸）（PAA）凝胶。由光敏PAA凝胶制成的厘米长的悬臂梁在蓝光（442 nm）和可见光（>490 nm）照射下表现出可逆的弯曲运动。在PAA凝胶的网络结构，在交替的蓝光和可见光的光照射过程中，其特征在于使用原位扫描显微镜动态光散射（SMILS），这表明可逆的网格尺寸的变化与偶氮苯部分的光异构化同步。PAA凝胶的光机械响应可能是由于聚合物主链的光诱导收缩和拉伸运动。光子散射的数值计算表明，在一个非常薄的表面层（约40 μm）的光异构化产生了大的宏观运动和大的应变的凝胶悬臂梁。但PAA凝胶的光响应能力随时间的延长而降低或消失。
Photoresponsive poly(amide acid) (PAA) gels containing multiple azobenzene units in a rigid aromatic backbone were synthesized. A centimeter-long cantilever made up of the photoresponsive PAA gel exhibited reversible bending motions upon blue (442 nm) and visible light (>490 nm) irradiation. The network structure in the PAA gels during alternating photoirradiation of blue and visible light was characterized using in situ scanning microscopic dynamic light scattering (SMILS), which revealed reversible mesh-size changes synchronized with the photoisomerization of azobenzene moieties. The photomechanical responses of the PAA gel were likely due to photoinduced contracting and stretching motions of the polymer backbone. A numerical calculation of photon absorptions revealed that photoisomerization in a very thin layer of the surface (∼40 μm) generated large macroscopic motion and large strain in the gel cantilever. The photoresponsive capability is, however, reduced or eliminated when the PAA gels are transfo...