The Synergistic Effects Between Liquid Crystal and Crystalline Phase on Photo-Responsive Elastomers Toward Quick Photo-Responsive Performance.

Adopting only a small amount of azobenzene molecular to design liquid crystal photo-responsive materials capable of quick response and flexible adjustability is in high demand but is challenging. Herein, we introduced azobenzene molecules into polyurethane elastomer containing crystalline structure for preparing azobenzene liquid-crystal elastomers (ALCEs) and discovered this phenomenon of the synergistic effects between liquid crystal and crystalline phase. The key point of the work is that the synthetic ALCEs can utilize the reversible isomerism capability of azobenzene molecules under light irradiation, which can pry the motion of the macromolecular crystalline region in system to realize the large macroscopic deformation of the photo-responsive behavior. Obviously, the ALCEs sample containing azobenzene molecule and polyethylene glycol (PEG) crystallization can quickly bend illuminated by UV light and rapidly straighten under green light. Under the same UV irradiation, the bending speed, final bending angle, recovery rate and recovery ratio of ALCEs are larger than that of ALCEs without any crystalline structure. This devised ALCEs based on the synergistic effects between liquid crystal and crystalline phase can break through the current dilemma that the application of traditional azobenzene photo-responsive materials is limited by their concentration, greatly expanding the design thought and their scope of application. This article is protected by copyright. All rights reserved.