Abstract

ARIAS DE FUENTES, O; JIMENEZ, C  and  BRATOV, A. Preliminary studies of PVC membranes based on 1-furoyl-3-phenylthiourea by impedance spectroscopy. Rev. mex. fis. [online]. 2006, vol.52, suppl.2, pp.26-28. ISSN 0035-001X.

The results obtained from characterization studies of sensor membranes by impedance spectroscopy are presented in this work. The PVC membrane used contained tris(2-ethylhexyl)phosphate as a plasticizer and 1-furoyl-3-phenylthiourea as an ionophore for lead ions. To perform this study, a special cell was designed by the authors. This made it possible to study the behavior of the electrical membrane characteristics with the lead concentrations in the solution. In all cases, the shape of the impedance spectra obtained showed a clear semicircle at high frequencies. This semicircle is associated with the bulk properties of the membranes. It was not possible to resolve another semicircle corresponding to the charge transfer at the interface. For this reason our study focussed on the bulk membrane electric characteristics. Both the dependence of the membrane resistance on the solution lead ion concentration and its behavior in time are reported.

Keywords : Impedance spectroscopy; PVC membrane;; chemical sensors.

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