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

TAGLIAZUCCHI, MARIO; GRUMELLI, DORIS; CALVO, ERNESTO J.

PHYSICAL CHEMISTRY CHEMICAL PHYSICS

Año: 2006 vol. 8 p. 5086 - 5095

1463-9076

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