Self-doped polymers doping mechanisms

In further studies, the self-doping mechanism of these polymers was verified by cyclic voltammetry, pH measurements and atomic absorption spectroscopy [17,20]. The cyclic voltammograms of the sodium salt and acid forms of poly(3-thiophene butanesulfonate) cast films are shown in... 

H+Ejection Study of the Acid Form of Polymers and the Self-Doping Mechanism... 

Elemental analysis and X-ray fluorescence measurements of films electrochemically oxidized in aqueous KCIO4 solutions, at pH values below the pK of the carboxylic acid indicate the absence of perchlorate counterions in the films [25]. This shows that the oxidized polymer backbone is charge compensated by covalently bound carboxylate anions and confirms the self-doping mechanism of poly( -(3-thienyl)octanoic acid). In contrast to films oxidized in aqueous solutions,... 

The mechanism for the SPAN layer changing the emission properties of the PPy VPV polymer is attributed to the formation of new emissive species due to protonation of the pyridyl units by SPAN. These species was identified by both absorption and PL experiments. Figure 9.15 shows the absorbance spectra of a PPy VPV layer, a SPAN layer, and a bilayer of PPy VPV/SPAN. SPAN is a self-doped, water-soluble conducting polymer with a room-temperature conductivity of 10-2 S/cm.18 It has a wide optical window from green to near infrared PPy VPV... 

Y. Ikenoue, J. Chiang, A. O. Patil, F. Wudl, A. J. Heeger, Verification of the cation-popping doping mechanism of self-doped polymers, Journal of the American Chemical Society 1988, 110, 2983. 

Recently, Fabre et al. [31] and Freund et al. [7, 8] used electro-chemically deposited, self-doped, boronic-acid-substituted, conducting polymers for saccharide and fluoride detection. Freund et al. prepared a potentiometric sensor for saccharides using self-doped PABA [7, 8]. The transduction mechanism in that system is reportedly the change in pKa of polyaniline that accompanies complexation, and the resulting change in the electrochemical potential. Sensors produced with this approach exhibit reversible responses with selectivity to various saccharides and 1,2-diols (Figure 3.22) that reflect their binding constants with phenylboronic acid observed in bulk solutions. The sensitivity... 

Other 3-substituted thiophenes that have been polymerized include 3-methoxy [309-311], other 3-alkoxy [312], 3-phenyl [313,314], 3-(4-methoxyphenyl) [314], 3-(4-trifluoromethylphenyl) [314], 3-bromo [315], 3-alkylsulfonatethiophene [316-318], and others [319-323]. Poly-3-alkylsulfonate thiophenes are particularly interesting due to a striking property. Sodium poly-3-thiophene-j8-ethanesulfonate and sodium poly-3-thiophene-6-butanesulfonate and their conjugate acids are water soluble in both the doped and undoped states [317,318]. Ikenoue et al. [318] examined the conduction mechanism for this self-doped conducting polymer. 

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