Studies on Charge Trapping in Polypyrrole and Poly (N-methylpyrrole) Based Bilayers of Polymers with Opposite Ion-Exchange Properties

Abstract

Charge trapping effects were studied for bilayers of conducting polymers: polypyrrole with immobilized poly (4-styrenesulfonate) ionsapoly (N-methylpyrrole) doped with perchlorate ions (PPy(PSS)aPMPy) as well for PPy(PSS)aPPy (where PPy is polypyrrole doped with perchlorate ions). Trapping properties resulting from low cationic conductivity of the outer polymer layer were evaluated by comparing redox charges of oxidationareduction of bilayers and single layers, obtained by voltammetric, chronoamperometric and chronopotentiometric method. The role of oxidation state of the polymer and electrolyte concentration was taken into consideration. Trapping effect was found to be enhanced for the outer polymer coating in the reduced state and for high electrolyte concentrations. The outer ®lm was also found to prevent the inner coating from irreversible oxidation at positive potentials.

Implications of layer-by-layer electrodeposition of polypyrrole from a solution of the same composition for ion transport in the polymer electrode

“…Hillman and Mallen [2][3][4] studied electroactive bilayers employing various conducting and redox polymers. Maksymiuk and coworkers [5][6][7][8][9][10], in a series of papers on bilayers and trilayers of polypyrrole, found conditions for charge trapping due to the ion-exchange and electronic conductivity properties of the composite layers. Ion and electron transports between the layers were as predicted from the properties of the layers in the stack.…”

Polypyrrole Nanofibers with Extended 1D Hierarchical Structure

“…Furthermore, the CV behavior indicates that the overlying PPy(DBS) is the cation exchanger so the underlying PPy fibers cannot eject ClO 4 − . Therefore, the fibers are blocked in the conducting oxidized state irrespective of the redox state of the overlayer, The CV characteristics of Pt/PPY(DBS) when confronted with the corresponding SEM images indicate an increasing dissolution of the polymer product with an increasing concentration of NaDBS.…”