Facile and effective repair of Pt/Nafion IPMC actuator by dip-coating of PVP@AgNPs

Ionic polymer metal composite (IPMC) always takes big risks of electrode cracking and peeling, which lead to energy wasting, waterloss, and uneven electric field distribution, thus hamper its commercial applications. To address this issue, we propose a facile and effective technique to repair the electrode fatigue by coating polyvinylpyrrolidone (PVP) encapsulated Ag nanoparticles (PVP@AgNPs) on the long-term used IPMC surface. To improve the electrochemical stability, the silver nanoparticles (Ag NPs) with a diameter of ∼34 nm are encapsulated by a 1.3 nm thick PVP film, thus forming a shell-core structure to resist corrosion from the electrolyte solution. Physiochemical investigations reveal that, PVP@AgNPs closely attach to the interior and exterior surfaces of the original Pt nanograin electrode, thus refreshing its electronic conductivity; the repaired IPMC actuator exhibits better electromechanical properties compared to its precursor actuator: 7.62 folds in displacement output, 9.38 folds in force output, and 9.73 folds in stable working time.