Ionic hydrogels have important value for applications in bionic skin and flexible sensor fields. However, general ionic hydrogels suffer from inevitable damage and reduction of service life after long-term use. Here, we propose a dualmechanism-driven strategy with a reversible metal coordination bond and dynamic hydrogen bond to construct a novel fast selfhealing ionic hydrogel via a facile "two-step" approach based on environmental-friendly natural resources as raw materials. The dual-mechanism-driven mode endows the hydrogel with excellent self-healing properties (3 h, 95.31%), tensile strength (479.8 kPa), compression strength (5.235 MPa), and fatigue resistance. The hydrogel also showed excellent self-adhesion performance, even underwater, as well as high and stable conductivity (σ = 17.54 mS• cm −1 ). In addition, it has an ion-responsive deformation feature so that the hydrogel can be shaped and restored in different ion solutions. As a sensor on human skin, the high sensitivity (GF = 2.363) enables it to detect and distinguish various human movements and even different letter pronunciations and pulses. These excellent performances lay a solid foundation for its application in bionic skin and flexible sensor fields.

The frequent occurrence of crude oil spills and the indiscriminate discharge of oily wastewater have caused serious environmental pollution. The existing separation methods have some defects and are not suitable for complex oil–water emulsions. Therefore, the efficient separation of complex oil–water emulsions has been of great interest to researchers. Asymmetric wettable Janus materials, which can efficiently separate complex oil–water emulsions, have attracted widespread attention. This comprehensive review systematically summarizes the research progress of asymmetric wettable Janus materials for oil–water separation in the last decade, and introduces, in detail, the preparation methods of them. Specifically, the latest research results of two-dimensional Janus materials, three-dimensional Janus materials, smart responsive Janus materials, and environmentally friendly Janus materials for oil–water separation are elaborated. Finally, ongoing challenges and outlook for the future research of asymmetric wettable Janus materials are presented.

At present, oil pollution on water has caused a disastrous and inestimable impact on ecological environment and economic development. There is an urgent need for high-efficient oil-water separation materials. As...

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