Producción Científica Profesorado

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



Alvarez Romero, Giaan Arturo

2010

Licona-Sánchez T. J., Álvarez-Romero G. A., Mendoza-Huizar L. H., Galán-Vidal C. A., Palomar-Pardavé M. E., Romero-Romo M., Herrera-Hernández H., Uruchurtu J., Juárez-García J. M., Nucleation and Growth Kinetics of Electrodeposited Sulfate-Doped Polypyrrole: Determination of the Diffusion Coefficient of SO42- in the Polymeric Membrane, The Journal of Physical Chemistry B, 2010, Vol 30, Núm 114, ISSN 1520-6106


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

Development of a novel composite sensor based on doped pyrrole selective to nitrate ions

Magnetic solid phase extraction based on phenyl silica adsorbent for the determination of tetracycli...

Electrochemical and AFM characterization of the electropolimerization of pyrrole over a graphiteepox...

Prevalence and Antimicrobial Resistance Patterns of Salmonella from Different Raw Foods in Mexico

Potentiometric Behavior of Diverse Polypyrrole-sulphate Films Electro Synthesized on Graphite - Epox...

Renewable stationary phase liquid magnetochromatography: determining aspartame and its hydrolysis pr...

Determination of glucose by flow injection analysis with amperometric detection at Fe(III)-(tris(3,5...

Facilitated transport of Hg(II) through novel activated composite membranes

Determination of primary amino acids in wines by high performance liquid magneto-chromatography

Construction and Evaluation of a Gold Tubular Electrode for Flow Analysis: Application to Speciation...