Nanostructured Modified Electrodes: Role of ions and solvent in redox active polyelectrolyte multilayer films.

M. TAGLIAZZUCHI; D. GRUMELLI; E.J. CALVO

PHYSICAL CHEMISTRY CHEMICAL PHYSICS

RCS Journal

Lugar: Cambridge UK; Año: 2006 vol. 43 p. 5086 - 5095

1463-9076

Electrodes modified layer-by-layer by self-assembly of redox active polyelectrolytes comprised of osmium bipyridine–pyridine derivatized poly(allyl-amine) and poly(vinyl) sulfonate have been studied by EQCM, ellipsometry, cyclic voltammetry and electrochemical impedance spectroscopy in aqueous solutions of different anions and cations. Redox driven swelling by solvent exchange during oxidation, in excess to the hydration number, occurs by perturbation of the equilibrium between the osmotic and elastic forces as a result of the electrochemical injection of charge into the film. The exchanged mass and volume change during redox switching strongly depends on the nature of the anion under anion Donnan permselectivity conditions.