The surface resistance response of a thin gold film electrode coated with poly(o-aminophenol)

R. TUCCERI

Shanghai

Conferencia; Conference on Thin Film Technology and Applications(TFTA2015); 2015

Conference on Thin Film Technology and Applications(TFTA2015)

The aim of this work was to qualitatively analyze how the electrochemical response of a metal surface is modified when it is gradually coated by poly(o-aminophenol) (POAP). To this end the electrochemical response of a thin gold film electrode was firstly studied in the presence of different adsorbates (perchlorate, sulfate and benzenesulfonate anions and the macromolecule poly(vinyl imidazole)). Then, the gold film electrode was gradually coated by POAP films of different thicknesses and again, its electrochemical response in the presence of the same adsorbates was recorded. Cyclic Voltammetry and the Surface Resistance technique were employed in this study. Dependence of the resistance change of the gold film on the external electrolyte composition at POAP thicknesses lower than 0.4 mC cm?2 was attributed to the discontinuous character of the polymer thickness on the gold surface. For polymer thicknesses higher than 0.4 mC cm?2, the resistance response of the gold film becomes independent of both the external electrolyte composition and POAP thickness. Thus, POAP thicknesses higher than 0.4 mC cm?2 seem to be compact enough at the metal|polymer interface to prevent the interaction of the species contained in the supporting electrolyte with the gold film surface.