Multifunctional Property Enhancement of 2-Acrylamido-2-methyl-1-propanesulfonic Acid/Acrylic Acid Hydrogels with Dual-ionic Liquid Functionalized Carbon Nanotubes

Conductive hydrogels with high mechanical strength, good adhesion, and high sensitivity are highly demanded for wearable electronics. A multifunctional hydrogel based on 2-acrylamido-2-methylpropanesulfonic acid (AMPS) and acrylic acid (AA) was synthesized via free-radical polymerization. The system incorporates dynamic hydrogen bonds from guanine–cytosine (G–C) base pairs and homogeneously dispersed carbon nanotubes (CNTs) modified using a dual-ionic liquid strategy. Short-chain (C 4 ) and long-chain (C 12 ) imidazole-based ionic liquids act synergistically to exfoliate and stabilize CNTs, facilitating uniform dispersion and strong interfacial bonding. Owing to the continuous conductive pathways formed by the CNTs, the hydrogel exhibited enhanced electrical conductivity with a gauge factor of 5.61, together with excellent short-term cyclic stability and responsiveness for monitoring dynamic human motions. The combination of covalent cross-linking, reversible hydrogen bonding, and reinforced nanofillers endows the hydrogel with high stretchability, good adhesion (5.5 kPa), and superior fatigue resistance, showing great potential for use in flexible wearable bioelectronics.