Voltammetric and waveguide spectroelectrochemical characterization of ultrathin poly (aniline)/poly (acrylic acid) films self-assembled on indium-tin oxide

被引：25

作者：

Ge, CH ^{[1
]}

Doherty, WJ ^{[1
]}

Mendes, SB ^{[1
]}

Armstrong, NR ^{[1
]}

Saavedra, SS ^{[1
]}

机构：

[1] Univ Arizona, Dept Chem, Tucson, AZ 85721 USA

来源：

TALANTA | 2005年 / 65卷 / 05期

关键词：

spectroelectrochemistry; conducting polymers poly(aniline); ATR spectroscopy;

D O I：

10.1016/j.talanta.2004.07.053

中图分类号：

O65 [分析化学];

学科分类号：

070302 ; 081704 ;

摘要：

We report on the spectroelectrochemical characterization of conducting polymer (CP) films, composed of alternating layers of poly(aniline) (PANI) and poly(acrylic acid) (PAA), deposited on ITO-coated, planar glass substrates using layer-by-layer self-assembly. Absorbance changes associated with voltammetrically induced redox changes in ultrathin films composed of only two bilayers (ITO/PANI/PAA/PANI/PAA) were monitored in real time using a unique multiple reflection, broadband attenuated total reflection (ATR) spectrometer. CP films in contact with pH 7 buffer undergo a single oxidation/reduction process, with ca. 12.5% of the aniline centers in the film being oxidized and reduced. The ATR spectra indicate that during an anodic sweep, the leucoemeralding form of PANI in these films is oxidized to generate both the emeraldine and pernigraniline forms simultaneously. A comparison of the behaviour observed during anodic and cathodic sweeps suggests that the rate of oxidation is limited by structural changes in the polymer film originating in electrostatic repulsion between positively charged PANI chains. (c) 2004 Elsevier B.V. All rights reserved.

引用

页码：1126 / 1131

页数：6

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[11] UNUSUAL QUASI-REVERSIBILITY (UQR) OR APPARENT NON-KINETIC HYSTERESIS IN CYCLIC VOLTAMMETRY - AN ELABORATION UPON THE IMPLICATIONS OF N-SHAPED FREE-ENERGY RELATIONSHIPS AS EXPLANATION [J].