figshare
Browse
ma7b01741_si_008.avi (7.72 MB)

Photomechanical Motion of Liquid-Crystalline Fibers Bending Away from a Light Source

Download (7.72 MB)
media
posted on 2017-10-19, 17:31 authored by Zhangxiang Cheng, Shudeng Ma, Yihe Zhang, Shuai Huang, Yuxuan Chen, Haifeng Yu
A series of photomechanical fibers was fabricated with a thermal drawing method by using liquid-crystalline random copolymers containing azobenzene and biphenyl groups in side chain. After being post-cross-linked under mild conditions, these fibers showed photoinduced bending motion away from the light source even though homogeneous alignment of mesogens was observed along the drawing direction. This abnormal photoinduced deformation of the obtained fibers is far different from previously reported light-directed motions about liquid-crystalline fiber and film materials. The interesting photomechanical deformation can be ascribed to the surface volume expansion caused by photoisomerization of azobenzene moieties. Then the photoinduced bending behaviors of these fibers containing different azobenzene concentrations and cross-linking densities were systematically investigated, suggesting that the location of photoresponsive azobenzene played an important role in deciding their photomechanical behaviors. This provides one convenient way of controlling over the photoinduced bending direction through the location of light-active moieties in side chain or cross-linker. In addition, irradiation of visible light accelerated the recovery of bent fibers. These fibers possess quick response, large deformation, and good thermal stability, indicating their promising applications for smart devices and energy conversion devices.

History