Guo M.,Tsinghua University |
Guo M.,Composites Co. Composites Center |
He Y.,Tsinghua University |
Wang X.,Tsinghua University
Gaodeng Xuexiao Huaxue Xuebao/Chemical Journal of Chinese Universities | Year: 2015
Surface-relief-gratings with further photo-crosslinkable property were prepared by softlithography using photo-sensitive polyimide containing cinnamate groups as “ink”. The effect of anisotropic photo-crosslinking on the thermos-stability of gratings and the alignment of liquid crystal(LC) on gratings was studied. The thermos-stability of the photo-cured gratings was significantly increased. No shape deformation was observed for the gratings after treated at a temperature 31 ℃ above the glass transition temperature of the un-cured polyimide. Both the un-exposed and exposed gratings induced uniform LC alignment on their surfaces. By irradiation with linear polarized UV light perpendicular to the gratings grooves, the LC alignment was enhanced. By changing the polarized direction of the UV light and controlling the depths of gratings, the LC alignment direction on the gratings was adjusted. This study result shows that the photo-crosslinkable gratings can achieve better thermo-stability, better LC alignment and adjustable aligned direction to achieve multi-domain alignment. The above research can lead to further understanding of the LC alignment mechanism. ©, 2015, Higher Education Press. All right reserved.