Películas de polipirrol electropolimerizadas en presencia de dodecilsulfato de sodio

Abstract

The electrodeposition of polypyrrole from 0.1 M pyrrole, 0.1 M sodiododecylsulphate, SDS, aqueous solution was studied using voltammetry and ellipsometry on gold electrodes. The thickness ( 4 < d < 140 nm) and the optical indices n � i k were obtained in the (450 nm < ë < 580 nm) visible optical region for the oxidised and reduced layer. During the oxidation and reduction in SDS there was not appreciable change in thickness. The optical indices showed only a partial reduction of the Ppy in the 0.1 < E < 0.9 V potential region, remaining the Ppy highly oxidised. After immersion in 0.1 M KCl it was observed an increase in electrocrhomism and pseudocapacity, and a 40 % decrease in thickness for the reduced layer. The optical indices at 0.9 V were similar to that in SDS, whereas at 0.1 V, it was observed significant reduction of the PPy.Utilizando elipsometria y voltametria se investiga la electrodeposicion de peliculas de polipirrol, Ppy, sobre electrodos de oro en soluciones acuosas de pirrol 0,1 M; sodiododecilsulfato, SDS, 0.1 M. La estructura para la pelicula oxidada y reducida se caracteriza mediante los indices opticos n . i k (region visible, 450 nm < �É < 580 nm) y el espesor (4 < d < 140 nm). Durante la oxidacion y reduccion en SDS no se observa cambio apreciable del espesor. Los indices opticos en la region 0.1 < E < 0.9 V muestran que el Ppy sufre solo reduccion parcial, permaneciendo con alto grado de oxidacion. Luego de inmersion en KCl 0,1 M se observa gran aumento de electrocromismo y pseudocapacidad, y disminucion de 40 % en espesor para la pelicula reducida. Los indices opticos a 0.9 V son similares a los en SDS, mientras que a 0.1 V se observa significativa reduccion del Ppy