Sunlight-Induced Deformation of Polyurethanes with Push-Pull Azobenzene and Application to Smart Fibers

Abstract

Conventional photomobile polymer materials containing azobenzene moieties were powered only by UV light because azobenzenes require UV light to induce trans-cis isomerization. Thus, the application of azobenzene-based actuators is limited by the low sensitivity to visible light. In this study, we introduced a visible-light-responsive push-pull azobenzene into main-chain polyurethanes and fabricated the “smart” materials that could respond intelligently to sunlight. Polyurethanes crosslinked by hydrogen bonding are soluble in solvents and capable of remolding, so that we could prepare polyurethane fibers by wet spinning process. The resulting smart fibers bent toward a light source when irradiated with sunlight.