Solvent-free stretchable photo-responsive supramolecular actuator topologically cross-linked by azobenzene-cyclodextrin based slide-ring system

The highly reversible photo-isomerization speed and efficiency of azobenzene make photomechanical polymers come true. While how to amplify the impact of molecular photo-isomerization upon the polymers to realize macro-motions remains a long way. Here we prepared a multi-stimuli-responsive supramolecular actuator via introducing slide-ring cross-linkers of azobenzene-cyclodextrin into polyacrylamide network. The result gel showed extremely quick response to various stimuli especially light even without solvent. Attributing to the slide-ring crosslinkers in the structure, the bending angle of CD-Azo gel reached to 40.0°within 0.5 s toward 365 nm light resource. In addition, overcoming the mechanical weakness of stimuli-sensitive hydrogel, the solvent-free polymer film exhibited high tensile strength of 15.00 MPa, elongation at breaking limit of 150% and Young's modulus of 0.34 MPa. A multi-stimuli-responsive supramolecular actuator via introducing slide-ring cross-linkers of azobenzene-cyclodextrin into polyacrylamide network was demonstrated. The gel showed good mechanical property and extremely quick response to various stimuli especially light even without solvent, its bending angle can reach to 40°within 0.5 s toward 365 nm light resource. [Display omitted] •A photoresponsive actuator topologically cross-linked by azobenzene-cyclodextrin based slide-ring structures was prepared.•Sliding motion strongly enhanced the actuators' responsiveness with bending speed of 87°/s irradiated upon 365 nm.•Movable cross-links endowed polymers with high tensile strength of 15 MPa and elongation at breaking limit of 150%.