Producción Científica Profesorado

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



Mendoza Huizar, Luis Humberto

2010

Nucleation and Growth Kinetics of Electrodeposited Sulfate- Doped Polypyrrole: Determination of the Diffusion Coefficient of SO42- In the Polymeric Membrane. 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 Aceptado 30-06-2010. The Journal of Physical Chemistry B. 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

Kinetics of Polypyrrole Films Doped with Sulphate Ions Electrodeposited Over Graphite - Epoxy Resin ...

Hydrogen bond studies in substituted N-(2-hydroxyphenyl)--2-[(4-methylbenzenesulfonyl)amino]acetamid...

Quantum chemical study of the electrochemical reduction of the [Co(H2O)6]2+ and [Co(NH3)5(H2O)]2+ io...

Magnetic transition phase diagram of cobalt clusters electrodeposited on HOPG: Experimental and micr...

Theoretical and Experimental Study of Cobalt Nucleation and Growth onto Gold Substrate with Differen...

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

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

Characterization of Main Anthocyanins Extracted from Pericarp Blue Corn by MALDI-ToF MS

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

A theoretical quantum study on the distribution of electrophilic and nucleophilic active sites on th...