Non‐Solvent‐Induced Phase Separation as a Scalable Route to Freestanding Conductive Polypyrrole–Polystyrene Films

ABSTRACT

Polypyrrole (PPy) is a widely researched conducting polymer, yet it faces challenges in processability when synthesized as powder through chemical oxidation. To overcome this, we synthesized a freestanding conductive film by incorporating PPy into a porous polystyrene (PS) matrix, using non‐solvent‐induced phase separation (NIPS). The newly found method allows control over PPy distribution by controlling porosity and offers a scalable, cost‐efficient alternative to commonly applied techniques like electrospinning and crosslinking. The resulting PS–PPy films were characterized for their morphology, structure, and electrical properties. A peak direct current conductivity of 21.2 S m ⁻¹ (and 20.1 S m ⁻¹ for the film with stable mechanical stability) was achieved, outperforming many PS–PPy systems without secondary fillers or dopants. A comprehensive investigation of charge transport was conducted, revealing a transition from one‐dimensional to three‐dimensional Mott's variable range hopping (VRH) and an increase in onset frequency with higher pyrrole loading concentrations, which enhanced connectivity between conducting PPy clusters within the insulating matrix. These findings suggest that NIPS‐based PS–PPy composites offer a promising, low‐cost, mechanically durable and scalable option for conducting films, with strong potential for applications in flexible electronics, electromagnetic shielding and sensing technologies.