Rapid Preparation of Ultrastrong and Repairable Poly(vinyl alcohol) Gel via a Facile One-Step Strategy

Abstract

Gels with simultaneously high strength, large strain, great toughness, intrinsic self-healing capability, and recyclability are highly attractive for industrial development and applications. However, their preparation remains a significant challenge owing to mutually exclusive mechanisms, let alone achieving such properties within a brief period via a facile method. In this study, a one-step “frozen salting-out” strategy is proposed to rapidly prepare poly(vinyl alcohol) (PVA) gels with outstanding mechanical properties through the construction of a robust polymer network. The gel exhibits a fracture strain of 1350%, an extremely high tensile stress of 31.1 MPa, and exceptional toughness of 247.7 MJ·m^–3. The damaged gel can heal in a manner similar to that of welding and can be recycled to restore its excellent mechanical properties. Furthermore, the stress of the gel can reach 117.0 MPa through a prestretching process that optimizes the polymer network. The entire preparation process is highly convenient. Time is of the essence, and the transformation from solution to robust gel requires approximately 1 h. This study provides a facile and effective strategy for preparing superstrong and tough gels.