Large scale preparation of polyaniline/polyvinyl alcohol hybrid films through in-situ chemical polymerization for flexible electrode materials

Abstract

Flexible electrode materials are inevitable for high-end applications such as wearable electronics, implantable microelectrodes, artificial muscles, various sensors, and biomedical devices. A simple and easy method for large scale preparation of mechanically stable and flexible electrode material using PANI and PVA films is presented. The hybrid films prepared through the chemical coating of PVA using an in-situ chemical polymerization of aniline were highly electroactive and comprised of coral-like nanowires of PANI grown on the surface of PVA films resulting large surface area and high porosity as evinced from SEM studies. FTIR spectra showed characteristic bands of PANI and PVA. Bandgap energies estimated were consistent with the electrical conductivity of the films. The doubly coated film showed an electrical conductivity as high as 4.0 × 10−2 S cm−1. The high electrochemical activity studied through cyclic voltammetry was attributed to the easy diffusion of ions through the porous nanowires of PANI on the surface of the films. Thermal studies revealed that hybrid films are thermally more stable. The tensile strength of the hybrid films was comparable with that of pure PVA film in the dry state while in the wet state the single coated film was mechanically more stable. Sorption studies showed that the mass swelling ratio of the hybrid films was decreased due to the incorporation of PANI into the hydrogel matrix. As the films were mechanically stable and highly electroactive and can be cut into pieces of any desirable size and shape we propose that they can be used as active electrode materials for sensors, supercapacitors, actuators, etc.