Producción Científica Profesorado

Nucleation and Growth Kinetics of Electrodeposited Sulfate-Doped Polypyrrole: Determination of the Diffusion Coefficient of SO42? in the Polymeric Membrane



Galan Vidal, Carlos Andres

2010

Licona-Sánchez, Teresa; Álvarez-Romero, Giaan; Mendoza-Huizar, Luis; Galan-Vidal, Carlos; Palomar, Manuel; Romero-Romo, Mario; Herrera-Hernández, Hector; Uruchurtu, Jorge; Juárez-García, Juan. Nucleation and growth kinetics of electrodeposited sulfate- doped polypyrrole: determination of the diffusion coefficient of SO42- in the polymeric membrane. Journal of Physical Chemistry B 214 (2010) 9737-9743 ISSN: 1520-6106 DOI: 10.1021/jp102676q.


Abstract


A kinetic study for the electrosynthesis of polypyrrole (Ppy) doped with SO42? ions is presented. Ppy films were electrochemically polymerized onto a graphite-epoxy resin electrode. Experimental current density transients (j?t) were obtained for three different potentiometric behaviors: anionic, cationic, and a combination. Theoretical models were used to fit the experimental j?t data to determine the nucleation and growth processes controlling the polymer synthesis. It was encountered that, in all cases, pyrrole electropolimerization involves two concomitant processes, namely, a Ppy diffusion limited multiple 3D nucleation and growth and pyrrole electro-oxidation on the growing surface of the Ppy nuclei. SEM analysis of the electrodes surfaces reveals that Ppy deposition occurred over most of the electrode surface by multiple nucleation of hemispheres, as the theoretical model used for the analysis of the current transients required. Hemispherical particles formed the polymeric film displaying different sizes. The order for the particle size was as follows: anionic > anionic?cationic > cationic. These results are congruent with those obtained by theoretical analysis of the corresponding current transients. Analysis of the impedance measurements recorded on the anionic Ppy film, immersed in an aqueous solution with different sulfate ion concentrations evidenced that SO42? ions diffuse through the Ppy film provoking a decrease of its electrical resistance and an increase of its dielectric constant. From the Warburg impedance coefficient, the sulfate coefficient of diffusion in the Ppy film was 1.38 × 10?9 cm2 s?1.



Producto de Investigación




Artículos relacionados

Analysis of the experimental pressuretemperature behavior in the isotropicnematic phase transition f...

A Voltammetric Study Of The Underpotential Deposition Of Cobalt Onto A Glassy Carbon Electrode

Electrochemical kinetic study about cobalt electrodeposition onto GCE and HOPG substrates from sulfa...

Cobalt electrodeposition onto highly oriented pyrolytic graphite (HOPG) electrode from ammonium sulf...

Cobalt Electrodeposition Process from Electrolytic Baths based on CoSO4 and (NH4)2SO4. Influence of ...

Cobalt electrodeposition on polycrystalline palladium. Influence of temperature on kinetic parameter...

Análisis del Comportamiento Presión-Temperatura en la Transición Isotrópico-Nemático del p-Azoxianis...

THEORETICAL STUDY ON THE MODIFICATION OF ACTIVE SITES IN GOLD SURFACES MODELED AS FINITE CLUSTERS: I...

The role of temperature in copper electrocrystallization in ammoniachloride solutions

Synthesis of Zn compounds derived from 1H-benzimidazol-2-ylmethanamine