Supramolecular Photonic Elastomers with Brilliant Structural Colors and Broad-Spectrum Responsiveness

Photonic elastomers (PEs) that can tune their colors through adjusting the lattice spacing of incorporated colloidal particles during mechanical deformation have shown great promise in visualized strain/stress sensors. However, the unsatisfactory structural color and narrow-spectrum responsiveness limit their broad applications. Herein, carbon-coated Fe3O4 nanoparticles (Fe3O4@C NPs) with a high refractive index (RI) and broad light absorption are employed for the construction of PEs with brilliant colors and broad-spectrum responsiveness by incorporating the Fe3O4@C NPs into amino-terminated poly(dimethylsiloxane) (amino-PDMS) polymer through supramolecular interactions. The inherent light-absorbing property, high RI, and supramolecular-induced short-range ordered arrangement of Fe3O4@C NPs imparts the PEs with brilliant and angle-independent structural color. By optimizing the content of Fe3O4@C NPs in the PEs, broad-spectrum responsiveness (stopband shifting approximate to 223 nm) and excellent recovery properties under a large strain can be achieved. The dynamic and reversible interaction endows the PEs with a healable capability. More interestingly, the incorporated Fe3O4@C NPs with photothermal capability can effectively absorb light and convert it into heat under light irradiation (solar light or near-infrared laser), accelerating healing of the damaged PEs. This study provides a new strategy for bioinspired construction of PEs for applications in the fields of sensing, colorful coating, and display.