Ion–Dipole Anchoring Enables Exceptional Hydration Stability in Polyquaternium-10/Poly(ionic liquids) Hydrogels for Flexible Electronics

A fundamental obstacle in developing high-performance ionic conductive hydrogels (ICHs) is the inherent trade-off between ionic conductivity and long-term hydration stability. Herein, we demonstrate ion–dipole anchoring as a powerful strategy to overcome this limitation. This strategy is realized in a semi-interpenetrating network hydrogel composed of polyquaternium-10 (PQ-10) and polymerized ionic liquid (PIL) via electron beam irradiation (PQ-10/PIL ICH). The ion–dipole anchoring effect arises from the strong specific interactions between the imidazolium cation (VEIM+) and bromide anions (Br–) from the PIL and water molecules, which drastically reduce water activity and suppress evaporation. Crucially, this anchoring mechanism operates independently within the continuous PIL phase, preserving high ionic conductivity (5.02 S m–1 at 25 °C) while enabling exceptional water retention (83.04% after 60 days). The PQ-10/PIL ICH demonstrates outstanding performance in flexible sensing and solid-state supercapacitors, retaining 85.00% capacitance after 10,000 cycles. This work establishes ion–dipole anchoring as a foundational design principle for creating durable and high-performance flexible electronic devices.