Ab Initio Modeling of Ion Interactions in PEDOT:PSS-PEO Polymer Systems and Experimental Observations in Corona...

This study investigates how ions generated during corona discharge, like protonated water clusters H₃O⁺(H₂O)_n, O₃^-, NO₃^-, and CO₃^•- (here and hereinafter an unpaired electron is indicated by the dot), interact with a conducting PEDOT:PSS-PEO blend containing 52 wt % PEO, a composition previously shown to possess near-metallic level conductivity. Using first-principles calculations, we identify potential adsorption sites, quantify adsorption energies, and analyze structural and electronic responses to adsorption. Negative ions exhibit weak, largely physisorptive interactions governed by electrostatic polarization, whereas hydronium-like cations bind strongly via proton transfer to PSS sulfonate groups, forming stable -SO₃H motifs. Charge-density-difference maps reveal local polarization for anions and clear charge transfer for cations. The pristine polymer model displays a very small band gap (∼0.1 eV), consistent with prior work, and ion adsorption perturbs the electronic structure in ways that may influence charge trapping and retention. These results suggest a mechanistic asymmetry for electret formation (a quasi-permanently charged dielectric): cations are chemically anchored, while anions are more likely to deliver transient charge or remain weakly bound, implications that inform corona-charging strategies for fiber filter media. Experimental observations are also included to demonstrate physical manifestations of charging conducting polymers incorporated in dielectric systems. Not only was a visible thunderbolt directed toward a conducting polymer "island" observed and macroscopically interpreted but also the Joule heating associated with it caused an observable waviness in the surrounding dielectric matrix which was explained. Direct corona charging using embedded conducting polymer "islands", as introduced and explored in the present work, is proposed as a potentially complementary method in filter media, alongside corona poling which is pure polarization.