Poly films self-doping

L.H.C. Mattoso, L.G. Patemo, S.P. Campana, and O.N. Oliveira Jr, Kinetics of adsorption of self-assembled films from doped poly(o-ethoxyaniUne), Synth. Met., 84(1-3), 123-124 (1997). 

In an attempt to produce carbazole polymers soluble in aqueous solutions, oligoether groups have been attached to the carbazole unit at the iV-position (28d) and the polymer prepared by chemical polymerization and electrochemical polymerization [105]. Due to the oligoether substituents, electrochemical polymerization can occur in aqueous solutions without the need for a cosolvent. Polymer films switch between a highly transmissive state to deep green upon oxidation. The self-doped polymer, poly[3,6-carbaz-9-yl)propanesulfonate] (28e), has also been produced, which is water-soluble and switches from a transmissive neutral state to a dark green oxidized state [106]. 

Kane-Maguire and Wallace et al. [122] were first to report on self-doped, optically active poly(2-methoxyaniline-5-sulfonic acid). They electropolymerized 2-methoxyaniline-5-sulfonic acid in the presence of R)- +)- or (S)-(—)-l-phenylethylamine. The poly(2-methoxyaniline-5-sulfonic acid) films formed using enantiomers of amines exhibit intense mirror image circular dichroism spectra (Figure 2.15) in the visible region. Wallace et al. suggest that the optical activity in poly(2-methoxyaniline-5-sulfonic acid) is probably due to electrostatic binding... 

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... 

The electrochemical synthesis of self-doped poly(3,4-ethylenedioxy-thiophene)-sulfonate in water without supporting electrolyte has been reported by Chevort et al. [30]. The monomer, sulfonated 3,4-ethylenedioxythiophene, was synthesized by various steps as shown in Figure 4.13. The electrochemical polymerization in water resulted in the formation of soluble oligomers. However, the copolymer films of poly(3,4-ethylenedioxythiophene)sulfonate could be prepared in water using an equimolar amount of 3,4-ethylenedioxythiophene without supporting electrolyte in the potential range of —1.4 to 1.2 V (vs... 

Reynolds et al. [45] have prepared a water-soluble, self-doped poly(4-(2,3-dihydrothieno[3,4-fc]-[l,4]dioxin-2-yl-methoxy)-l-butanesulfonic acid, sodium salt) (PEDOT-S) (Figure 4.28) by chemical synthesis using ferric chloride in chloroform. The monomer, sulfonated 3,4-ethylenedioxythiophene, was synthesized by following Chevrot et al. s synthesis method as shown in Figure 4.13 [30]. The electrochromic and hole-transporting multilayer films of PEDOT-S and poly(allylamine... 

Figure 5.5 Characteristic UV-Vis NIR absorption spectra of self-doped poly(3-alkylsulfonate pyrrole) thin films with propyl (n = 3), butyl (n = 4), and hexyl ( = 6) derivatives, respectively, on ITO glass electrodes. (Reprinted with permission from Chemistry of Materials, 1, 650. Copyright (1989) American Chemical Society.)...

Teixidor et al. [49] synthesized self-doped polypyrrole by using the nonconventional covalently bound low charge density anion [3,3 -Co(1,2-C2B9Hio)2] to a pyrrole unit via a spacer diether aliphatic chain. The electropolymerization of the potassium salt of the monomer, denoted as [1] , (Figure 5.7) was obtained in dry acetonitrile with tetrabutyl ammonium chloride in the potential range of —0.5 to 1.7V vs Ag/AgCl. Similarly a copolymer of [1] was prepared with pyrrole monomer (ratio 1 1) under identical conditions. The conductivity of poly[l] and copolymer films measured using a four-point probe... 

Reynolds et al. [54] reported the electrochemical synthesis of self-doped, water-soluble, N-propanesulfonated poly(3,4-propylenedioxypy-rrole). The sulfonated monomer, N-propanesulfonate-substituted 3,4-propylenedioxypyrrole (N-PrS PProDOP) was prepared by treating 3,4-propylenedioxypyrrole with NaH in dry tetrahydrofuran and 1-propanesulfonate as shown in Figure 5.10. The poly(N-PrS PProDOP) films were synthesized in a mixture of propylene carbonate and water (94 6) with supporting electrolyte LiC104 in the potential range —0.4 to... 

The reports on electrochemical synthesis of self-doped sulfonated polypyrroles in aqueous media are limited in comparison with nonaqueous media. The first report on the synthesis of copolymer poly(pyrroleco-(3-(pyrrol-l-yl)propanesulfonate)) films in aqueous media for ion exchange was by Rajeshwar et al. [56]. The copolymer films were prepared without... 

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