Robust Solvatochromic Gels for Self‐defensive Smart Windows

Abstract Smart materials that can dynamically modulate incident light provide a broad prospect for the development of smart windows. However, the absence of capability to create smart materials with rapid transmittance switchability and mechanical robustness has restricted the realization of self‐defensive smart windows. Here, a solvatochromic alcogel designed by cellulose–polyacrylamide supramolecular configuration for developing a self‐defensive smart window is reported. The alcogel with compact nano‐bulge structures exhibits reversible and rapid switching of transparency between 85% and 5%, cycle time less than 8 s, and has strong mechanical robustness with elastic modulus of over 60 MPa. With this smart alcogel, the proposed self‐defensive smart window not only shows real‐time and reliable adjustment of transparency but also outputs a strong mechanical impact resistance of up to 42.8 kJ m −2 , 10 and 12 times higher than that of a normal glass and photochromic window, respectively. It is believed that this study will open new opportunities for both fabrication and application of biological gels in smart windows and intelligent devices.