Photomobile Polymer Materials: Photoresponsive Behavior of Cross-Linked Liquid-Crystalline Polymers with Mesomorphic Diarylethenes

Cross-linked liquid-crystalline (LC) polymers with a mesomorphic diarylethene were prepared to demonstrate a versatile strategy for cross-linked photochromic LC polymers as photomobile materials. Upon exposure to UV light to cause photocyclization of the diarylethene chromophore, the cross-linked polymer films bend toward an actinic light source. By irradiation with visible light to cause a closed-ring to open-ring isomerization, the bent films revert to the initial flat state. Without visible-light irradiation, the bent films remain bent even at 120 degrees C, indicating high thermal stability of the cross-linked diarylethene LC polymers.