کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
196005 459830 2006 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Impedance spectroscopy of oxidized polyaniline and poly(o-ethoxyaniline) thin film modified Pt electrodes
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی مهندسی شیمی (عمومی)
پیش نمایش صفحه اول مقاله
Impedance spectroscopy of oxidized polyaniline and poly(o-ethoxyaniline) thin film modified Pt electrodes
چکیده انگلیسی

Impedance spectra of potentiodynamically formed polyaniline (PANI) and poly(o-ethoxyaniline) (POEA), thin film modified Pt electrodes measured at potentials of conductive, emeraldine form in H2SO4 electrolyte solution were reported. Specific features of spectra obtained for films of different voltammetric charge densities were modelled and interpreted according to “homogeneous” and “distributed” impedance models. The values of charging capacitances of different PANI and POEA films were found independent of the model used. Charging of polymer films was in terms of both models controlled by charge transport processes being ion diffusion and migration in the first case, and polymer film and ionic conductivities in the second case. Distortion from Warburg-like response observed for both polymer films was explained by either differences in relaxation times of diffusion and migration processes, or by impedance of ionic channels with “anomalous” frequency dispersion. There were some discrepancies between theories and results suggesting that “homogeneous” model was more appropriate for POEA films while “distributed” model was more appropriate for PANI films, at least if both films were formed and measured in presently described conditions.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Electrochimica Acta - Volume 51, Issue 17, 25 April 2006, Pages 3417–3428
نویسندگان
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