光控取向材料F-PVCN表面偏光性及预倾角与曝光的非单调关系

Non-monotonic Exposure Dependence of the Pretilt Angle and Surface Polarity of the Photo-orientant F-PVCN

本文报导首次观察到在光控取向材料表面上液晶分子预倾角与紫外光非单调曝光的关系。我们发现这种在加氟聚乙烯基肉桂酸(PVCN-F)表面预倾角与曝光的关系是非单调性的,而在无氟PVCN时显示的关系是单调递减的。这些和PVCN-F和PVCN表面的入射光偏光性变化有关系。实验结果表明表面偏光性和入射光变化对于光控取向材料的预倾角产生在机理上起着很重要的作用。

We report on the first observation of a non-monotonic UV exposure dependence of the pretilt angle of a liquid crystal on a photoaligning surface. We found this non-monotonic dependence on fluorinated poly(vinyl cinnamate) (PVCN-F) surface while non-fluorinated PVCN revealed a monotonic decrease of the pretilt angle with exposure. These dependences correlate with light-induced changes of the polarity and the light-induced changes in mechanisms of pretilt angle generation on photoaligning materials.