A Multifunctional Imidazolium-Based Silicone Material with Conductivity, Self-Healing, Fluorescence, and Stretching Sensitivity.

Wearable devices have gained substantial interest for a wide range of applications, including biomonitoring and entertainment. They are basically composed of sensors and substrate materials. Recently, silicone materials have been extensively used in wearable devices because of their unique properties. Silicone materials, which possess remarkable insulation, predominantly serve as a substrate instead of a signaling material due to the indispensable electrical conductivity in wearable devices. Herein, a novel kind of silicone material, with both good conductivity and excellent self-healing efficiency, is designed by introducing imidazolium into the silicone polymer in one step. The free ions afford an ionic conductivity as high as 2.79 × 10-4 S m-1 , representing a significant improvement over traditional silicone materials. Because of the good conductivity, the silicone material is sensitive to stretching and can be applied as a flexible sensor. On the other hand, the material exhibits a high healing efficiency, reaching 89% in 6 h, due to the dynamic supramolecular interaction of the ion crosslink sites at the crack surface. Furthermore, the silicone material emits a yellow-green fluorescence under UV light.