1D Nanomaterial-Reinforced IPN Hydrogels with Enhanced Mechanical and Electrical Properties

Hydrogels, composed of cross-linked polymer networks with high water content, are widely explored for biomedical applications due to their tunable properties and biocompatibility; however, their limited mechanical strength restricts their use in load-bearing or dynamic environments, a challenge that can be addressed by incorporating conductive nanoparticles to enhance both mechanical resilience and electrical conductivity. In this work, we unveil the formation mechanism of the silver nanowire (AgNW) reinforced Acrylic Acid/Acrylamide/Polyethylene glycol diacrylate (AgNW/P(AAm-co-AAc-co-PEGDA)) hydrogels. We investigate the impact of AgNW concentration on the structural, mechanical, and electrical properties of the hydrogel network. Our findings reveal that above 6 wt% AgNW concentration, nanowire moieties form a secondary physical network, which significantly enhances the storage modulus (G′) and electrical conductivity (s). At 8 wt% AgNW, the hydrogel achieves a conductivity of nearly 440 S/m at 6000 MHz, coupled with a G′ of 4 kPa, demonstrating its potential for applications requiring both mechanical resilience and high conductivity. Further doping (>8 wt%), on the other hand, leads to an aggregation that results in a decrease in the conductivity. The synergistic effect of AgNW reinforcement and the interpenetrating polymer network (IPN) structure enhances the hydrogel’s stability, ensuring long-term performance in dynamic aqueous environments. Frequency-dependent electrical measurements further indicate tunable conductivity, making these hydrogels promising candidates for applications in flexible electronics, bioelectronic interfaces, and implantable sensing systems.