A novel conductive composite gel based on polyvinyl alcohol/polymerizable deep eutectic solvent with superior tear resistance, tensile properties and recyclability

The polymerizable deep eutectic gel has become one of the essential materials for wearable electronic devices because of its low volatility, excellent ionic conductivity, and electrochemical stability. Finding strategies to improve the strength of gel-like materials was a huge challenge. In this paper, we present for the first time a deep eutectic solvent (DESD) with hydrogen bond acceptors as polymerizable components. We also discover a new strategy for inducing PVA crystallization with it as the core. Using DESD can induce PVA crystallization extremely easily, avoiding the complicated steps of traditional PVA hydrogels which need to cycle freeze-thaw to induce crystallization. The crystalline domain formed by PVA acts as the physical cross-linking site, greatly enhancing the strength (stress up to 4 MPa, strain up to 1558%) and tear resistance (tearing energy up to 12.3 kJ/m2) of eutectic gel. The fully non-covalent cross-linked structure made eutectic gels have excellent self healing ability (99%) and recycling ability. This strategy provided a new idea for the preparation of high strength ionic conductive gel. High strength and recyclability gave gel great development space in the engineering application field.