Self-Adhesive Self-Healing Thermochromic Ionogels for Smart Windows with Excellent Environmental and Mechanical Stability, Solar Modulation and Antifogging Capabilities.

Current thermochromic materials used in smart windows still face challenges, such as poor mechanical and environmental stability, unsatisfactory solar modulation capacity, and low transparency. Herein, we report the first self-adhesive self-healing thermochromic ionogels with excellent mechanical and environmental stability, antifogging capability, transparency, and solar modulation capability by loading binary ionic liquids (ILs) into rational-designed self-healing poly(urethaneurea) with acylsemicarbazide (ASCZ) moieties that have reversible and multiple hydrogen bonds and demonstrate their feasibility as smart windows with reliability and long service life. The self-healing thermochromic ionogels can switch between transparent and opaque without leakage or shrinkage, by the constrained reversible phase separation of ILs within the ionogels. The ionogels have the highest transparency and solar modulation capability among reported thermochromic materials and such excellent solar modulation capability can be well maintained after undergoing 1000 transitions, stretches, and bends, and storage at -30°C, 60°C, 90% RH, and vacuum environment for 2 months. The formation of high-density hydrogen bonds among the ASCZ moieties contributes to the excellent mechanical strength of the ionogels and allows the thermochromic ionogels to spontaneously heal their damages and be fully recycled at room temperature without the loss of thermochromic capabilities. This article is protected by copyright. All rights reserved.