Shi, P., Wang, Y., Tjiu, W. W., Zhang, C., & Liu, T. (2021). Highly Stretchable, Fast Self-Healing, and Waterproof Fluorinated Copolymer Ionogels with Selectively Enriched Ionic Liquids for Human-Motion Detection. ACS Applied Materials & Interfaces, 13(41), 49358–49368. https://doi.org/10.1021/acsami.1c16081
The development of waterproof ionogels with high stretchability and fast self-healing performance is essential for stretchable ionic conductors in sophisticated skin-inspired wearable sensors but can be rarely met in one material. Herein, a semicrystalline fluorinated copolymer ionogel (SFCI) with extremely high
stretchability, underwater stability, and fast self-healability was fabricated, among which hydrophobic ionic liquids ([BMIM][TFSI]) were selectively enriched in fluoroacrylate segment domains of the fluorinated copolymer matrix through unique ion−dipole interactions. Benefiting from the reversible ion−dipole interactions between the [BMIM][TFSI] and fluoroacrylate segment domains as well as the physical cross-linking effects of semicrystalline oligoethylene glycol domains, the SFCI exhibited ultrastretchability (&gt;6000%), fast room-temperature self-healability (&gt;96% healing efficiency after cutting and self-healing for 30 min), and outstanding elasticity. In addition, the representative SFCI also exhibited high-temperature tolerance up to 300 °C, antifreezing performance as low as −35 °C, and high transparency (&gt;93% visible-light transmittance). As a result, the as-obtained SFCI can readily be used as a highly stretchable ionic conductor in skin-inspired wearable sensors with waterproof performance for real-time detecting physiological human activities. These attractive features illustrate that the developed ultrastretchable and rapidly self-healable ionogels with unique waterproofness are promising candidates especially for sophisticated wearable strain sensing applications in complex and extreme environments.
This work was supported by the National Natural Science Foundation of China (Grant No. 52122303 and 21875033)