Self-Assembled Redox Polyelectrolyte-Surfactant Complexes:Nanostructure and Electron Transfer Characteristics ofSupramolecular Films with Built-In Electroactive Chemical Functions

M. LORENA CORTEZ; GRACIELA A. GONZÁLEZ; MARCELO CEOLÍN; OMAR AZZARONI; FERNANDO BATTAGLINI

ELECTROCHIMICA ACTA

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2014 vol. 118 p. 124 - 129

0013-4686

The mesostructural and electrochemical characterization of a redox-active polyelectrolyte-surfactantcomplex formed by polyallylamine tagged with an osmium complex and dodecylsulfate is presented.X-ray reflectivity (XRR), grazing-incidence small-angle X-ray scattering (GISAXS), X-ray photoelectronspectroscopy (XPS), contact angle goniometry (CA) and cyclic voltammetry (CV), including the numeri-cal simulation of the voltammetric response, were employed to analyze the structure, stability and theelectrochemical response of these supramolecular films. In contrast to redox-active polyelectrolyte mul-tilayers (PEMs), the self-assembled system presented here shows a mesoscopic order yielding a film oflayered structure very stable to an aqueous environment where the hydrophilic moieties (amino andsulfate groups) are not exposed to the solution since a contact angle of 95 grades is observed upon exposure towater. However, the film shows a self-exchange electron transfer mechanism with an apparent diffusion coefficient of 2 x10-9 cm2  s-1 for a film of 300 nm of thickness. This behavior shows that the film exposedto an aqueous solution undergoes a fast electron transfer process to/from the electrode surface and ionsto/from the electrolyte solution.