Journal ArticleDOI
Dispersion Polymerization of Aniline in Different Media: A UV−Visible Spectroscopic and Kinetic Study
TLDR
In this paper, the authors studied the course of dispersion polymerization of aniline using ammonium peroxodisulfate (APS) as initiator oxidant and poly(vinyl alcohol) as stabilizer in different media, viz., water (1 M HCl), water (pH = 2.41, [aniline] ≡ [HCl]), and aqueous ethanol (1M HCl) was followed spectrophotometrically.Abstract:
The course of dispersion polymerization of aniline using ammonium peroxodisulfate (APS) as initiator oxidant and poly(vinyl alcohol) as stabilizer in different media, viz., water (1 M HCl), water (pH = 2.41, [aniline] ≡ [HCl]), and aqueous ethanol (1 M HCl), was followed spectrophotometrically. It was found that the absorption peak positions for the pernigraniline salt change markedly with change in acidity and [APS]/[aniline] ratio. The spectral shape also changes greatly when water is replaced by aqueous ethanol. The evolution of the spectra with time was used to generate rate curves which reveal the autocatalytic nature of the reaction. The activation energies of the reaction in the various media were evaluated for both the induction period and the polymerization period using the inverse of the times of these periods as representing average rates for the periods, respectively. The activation energies increase with decrease in medium polarity and/or acidity. These variations have been discussed.read more
Citations
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Journal ArticleDOI
Progress in preparation, processing and applications of polyaniline
TL;DR: A detailed discussion on the mechanism of electrical conduction in PANI and the factors those influence the conductivity of PANI is also included in this paper, where the problems of effective utilization and the methods adopted to overcome these problems are also provided.
Journal ArticleDOI
Evolution of polyaniline nanotubes: The oxidation of aniline in water
Miroslava Trchová,Ivana Sedĕnková,Elena N. Konyushenko,Jaroslav Stejskal,Petr Holler,Gordana Ćirić-Marjanović +5 more
TL;DR: Gel-permeation chromatography indicates that aniline oligomers are produced at first at high pH, while polyaniline follows after the pH becomes sufficiently low, which indicates that the kinetic course of polymerization is controlled by the acidity level.
Journal ArticleDOI
In-situ polymerized polyaniline films
TL;DR: In this paper, the thickness and electrical properties of polyaniline hydrochloride films were determined by optical interferometry and linked to their optical absorption at the wavelength 400 nm, A 400 =(5.4±0.2)×10 −3 d f (in nm).
Journal ArticleDOI
Morphological Evolution of Self-Assembled Polyaniline Nanostuctures Obtained by pH-stat Chemical Oxidation
TL;DR: In this article, the self-assembly of polyaniline was carried out at constant acidity, investigating six separate pH levels (pH = 1, 2, 3, 4, 5, 6, and 6).
Journal ArticleDOI
In-situ polymerized polyaniline films. 5. Brush-like chain ordering
Irina Sapurina,A. Yu. Osadchev,B.Z. Volchek,Miroslava Trchová,Andrea Riede,Jaroslav Stejskal +5 more
TL;DR: In this paper, the polymerization conditions for preparation of ordered in-situ polymerized polyaniline (PANI) films were established and the observed linear relation between film thickness and molecular weight of PANI also supported the ordering hypothesis.
References
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Journal ArticleDOI
Polyanilines: a novel class of conducting polymers
TL;DR: The polyanilines are a class of polymers the base form of which has the general formula [graphic omitted] containing y reduced and (1 -y) oxidized repeat groups.
Journal ArticleDOI
Polaron lattice in highly conducting polyaniline: Theoretical and optical studies.
Sven Stafström,Jean-Luc Brédas,Arthur J. Epstein,H. S. Woo,David B. Tanner,W. S. Huang,Alan G. MacDiarmid +6 more
TL;DR: In this paper, the authors present optical-absorption data together with band-structure calculations for the polaron lattice and bipolaron lattice for the highly conducting form of polyaniline, proton-doped polyemeraldine.
Journal ArticleDOI
Influence of chemical polymerization conditions on the properties of polyaniline
TL;DR: In this article, the polymerization of aniline in aqueous solutions was studied as a function of a wide variety of synthesis parameters, such as pH, relative concentration of reactants, polymerization temperature and time.
Journal ArticleDOI
Camphorsulfonic Acid Fully Doped Polyaniline Emeraldine Salt: Conformations in Different Solvents Studied by an Ultraviolet/Visible/Near-Infrared Spectroscopic Method
TL;DR: In this article, the authors showed that PANI-HCSA has a more expanded coillike conformation in m-cresol, p-Cresol and 2-chlorophenol than in chloroform, NMP, DMF and benzyl alcohol.
Journal ArticleDOI
Optical properties of polyaniline
W.S. Huang,Alan G. MacDiarmid +1 more
TL;DR: In this paper, the authors studied the optical absorption change of polyaniline at various levels of oxidation and protonation, and the evolution of band structure corresponding to the optical-absorption change during each specific oxidation state is studied by gradually changing the acid strength of the solution to which the polymer is subjected.
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