Preparation and assembly of five photoresponsive polymers to achieve complex light-induced shape deformations. (15th April 2018) - Fang, Tianyu
Abstract: Five photoresponsive polymers towards ultraviolet (UV), visible, and near-infrared (NIR) light were prepared and assembled to achieve complicated light-induced shape deformation. The UV light responsive polymer was contributed by a synthesized linear polyurethane elastomer (azo-PU) containing azobenzene groups in the main chains, which presented both shape-memory effect and UV light-induced shape deformation behavior. The other four polymers that were sensitive to visible or NIR light consisted of crosslinked poly(ethylene-co-vinyl acetate) (EVA) composites mixing with gold nanoparticles (AuNPs), Nd(TTA)3 Phen, Yb(TTA)3 Phen, and Sm(TTA)3 Phen as photothermal fillers, respectively. The results showed that the shape recoveries of these EVA composites were triggered merely by visible and/or NIR light with suitable wavelengths. Moreover, the assembly of the prepared five light-induced polymers in three different manners improved the spatiotemporal control of complicated shape deformations upon different light illumination sequences. Benefiting from the creation and assembly of five photoresponsive polymers with high wavelength selectivities, complex shapes of polymer specimens can be achieved in a remote and non-contact manner via simply tuning irradiation sequences. The reported materials here and their assembly manners provide a strategy to expand the applications of photoresponsive polymers. Highlights: Five photoresponsive polymers were prepared and assembled to induce multiple shape deformations. The UV light responsive polymer was polyurethane having azobenzene groups in the main chains. The other four polymers were crosslinked poly(ethylene-co-vinyl acetate) composites mixing with photothermal fillers. The EVA composites recalled their original shapes upon the illuminations merely by the suitable visible and/or NIR light. The assembly in three manners improved the spatiotemporal control over shape deformations in a remote manner. Graphical abstract: Five photoresponsive polymers were prepared and assembled in three manners to achieve complicated light-induced shape deformation of polymer specimens, which further expand the applications of light-induced polymers.