Stiffen and toughen poly(vinyl alcohol) gels via synergistic dehydration and salting out

Poly(vinyl alcohol) (PVA) gels are widely used in the fields of biomedicine, flexible electronics, soft machines, etc. However, they face significant performance limitations due to their poor mechanical properties and the difficulty in balancing stiffness and toughness. This work proposes a strategy combining dehydration and salting‑out to develop a PVA gel material with both high stiffness and high toughness. The dehydration process induces the formation of a high-density polymer network with high crystallinity, and the subsequent organic solvent-assisted salting-out effect regulates the aggregate structure while effectively preserving the retention of the crystalline structure. The resultant gel achieves tensile stress of 66.2 MPa, stiffness of 334.2 MPa and toughness of 235.7 MJ m^-3, demonstrating a synergistic enhancement that reconciles the long-standing stiffness-toughness trade-off in PVA gels. This study achieves a significant enhancement in the mechanical properties of PVA gel materials through a dehydration-salting out strategy, offering an effective approach to designing high-performance polymeric gels.