‘Polyaniline’: Protonic acid doping of the emeraldine form to the metallic regime

Chiang, J.; MacDiarmid, Alan G.

doi:10.1016/0379-6779(86)90070-6

Cited by 1,911 publications

(856 citation statements)

References 23 publications

Supporting

Mentioning

814

Contrasting

Unclassified

Order By: Relevance

“…Therefore, they could show electrochemical behavior resembling anilines [1][2][3] and/or phenols [4,5]. In earlier works, we have studied the oxidation of the three isomers of aminophenols using in situ FTIR spectroscopy [6].…”

Section: Introductionmentioning

confidence: 99%

Spectroelectrochemical study of the oxidation of diaminophenols on platinum electrodes in acidic medium

Salavagione

Arias

Garcés

et al. 2005

Electrochimica Acta

View full text Add to dashboard Cite

The electrochemical oxidation of 2,3-2,4-and 2,5-diaminophenol, on platinum electrode, in acid medium was studied using cyclic voltammetry, in situ UV-vis and in situ FTIR spectroscopies. The spectroscopic data indicates that 2,4-diaminophenol suffers hydrolysis giving the formation of 2-amino-hydroquinone/2-amino-p-benzoquinone in solution. The oxidation mechanism of 2,5-diaminophenol is similar to the p-phenylenediamine giving 2-hydroxy-p-benzoquinoneimine and its hydrolysis product, 2-hydroxy-p-benzoquinone. The electrochemical results suggest that 2,3-diaminophenol generates a non-electroactive polymeric material on the electrode surface.

show abstract

Section: Introductionmentioning

confidence: 99%

Spectroelectrochemical study of the oxidation of diaminophenols on platinum electrodes in acidic medium

Salavagione

Arias

Garcés

et al. 2005

Electrochimica Acta

View full text Add to dashboard Cite

show abstract

“…1, 2 The electrical properties of PANI are sensitively dependent on its oxidation and protonation states, of which the emeraldine state (see Figure 1) with a wide range of electrical conductivity can be achieved by simple doping/dedoping chemistry based on acidic/basic reactions. [1][2][3] The conventional chemical oxidative polymerization of aniline (AN) is carried out in a strong acidic solution and initiated by adding an oxidant (such as ammonium peroxydisulfate, APS). 3 From a technical point of view, the above-mentioned preparation for PANI is a simple process, but the formation mechanism involves an intricate interplay of consecutive chemical and physical reactions.…”

Section: Introductionmentioning

confidence: 99%

“…3 From a technical point of view, the above-mentioned preparation for PANI is a simple process, but the formation mechanism involves an intricate interplay of consecutive chemical and physical reactions. [3][4][5][6][7][8][9][10][11][12] To account for the formation of PANI, the following basic mechanisms were reported. The redox reaction of neutral ANs with APS produces AN radicals.…”

mentioning

confidence: 99%

Polymerization of aniline under various concentrations of APS and HCl

Tang

Wang

Lin

et al. 2011

Polym J

103

View full text Add to dashboard Cite

Effects from various initial molar ratios of aniline (AN), ammonium peroxydisulfate (APS) and HCl ( [AN]: [APS]: [HCl]) on the polymerization of AN were investigated. First, a scheme derived from a molecular point of view was proposed to distinguish formation mechanisms based on their initial conditions. Thereafter, by choosing a relatively low ratio of Keywords: aniline; formation mechanism; phenazine-like oligomers; polyaniline INTRODUCTION Polyaniline (PANI) is one of the most important conducting and semi-conducting polymers widely used in organic optoelectronic devices and has attracted considerable attention recently because of its tunable electrical conductivity, easy preparation from common chemicals and excellent thermal and environmental stabilities. 1,2 The electrical properties of PANI are sensitively dependent on its oxidation and protonation states, of which the emeraldine state (see Figure 1) with a wide range of electrical conductivity can be achieved by simple doping/dedoping chemistry based on acidic/basic reactions. 1-3 The conventional chemical oxidative polymerization of aniline (AN) is carried out in a strong acidic solution and initiated by adding an oxidant (such as ammonium peroxydisulfate, APS). 3 From a technical point of view, the above-mentioned preparation for PANI is a simple process, but the formation mechanism involves an intricate interplay of consecutive chemical and physical reactions. [3][4][5][6][7][8][9][10][11][12] To account for the formation of PANI, the following basic mechanisms were reported. The redox reaction of neutral ANs with APS produces AN radicals. 4 Under a neutral or alkaline condition, the mixed ortho-para coupling of AN radicals together with oxidative intramolecular cyclization forms AN oligomers with phenazine-like structures at the initial stage (see Figures 2a and b for phenazine and phenazine-like trimer). 9-13 The oxidation of AN and AN oligomers with APS both release protons, and the pH of the solution falls. [12][13][14][15][16][17][18][19][20] In a strong acidic environment, the formation of a para-coupled structure

show abstract

“…These films were later oxidized by (NH 4 ) 2 S 2 O 8 (Aldrich) in acidic (HCl or H 2 SO 4 ) aqueous solutions according to the well-established methods. 9 Subsequent reduction was achieved by treating the films with aqueous NH 4 OH or NaOH. The blend films were prepared by first preparing the corresponding polyaniline either in conducting (acidic) or nonconducting (basic) forms and later dissolving it in THF together with PVC and casting the films after evaporation of the solvent.…”

Section: Methodsmentioning

confidence: 99%

Spectroscopic Investigation of Onset and Enhancement of Electrical Conductivity in PVC/PANI Composites and Blends by γ-ray or UV Irradiation

1998

View full text Add to dashboard Cite

Electrical conductivity of blends and composites of poly(vinyl chloride) (PVC) with nonconducting polyaniline (PANI) increases when they are subjected to γ-rays or UV radiation. This is attributed to a radiation-induced dehydrochlorination (loss of HCl) of PVC, which in turn oxidizes (dopes) PANI within the PVC matrix causing the increase in electrical conductivity of these films. XPS, UV-vis-NIR and FTIR spectroscopic methods are used to characterize and verify this novel process. After the films are subjected to γ-rays (or UV radiation) the intensities in the XPS spectra of both -N + -and Cl -peaks increase, confirming the increase in charged species within the PVC matrix. Similar observations attributable to radiation-induced electrical conductivity are also observed in both the UV-vis-NIR and FTIR spectra. This radiation-induced conductivity can also be reversed to some extent by further exposing the films to NH 3 vapors, where the oxidized centers are partially reduced (undoped). Several UV/NH 3 /UV cycles can be performed without much loss in conductivity-and/or conductivity-related spectroscopic features. The onset of the photoinduced conductivity both in PVC-only and PVC/PANI composite films is determined to be 300 nm (4.1 eV), which coincides with the first UV absorption band of PVC.

show abstract

‘Polyaniline’: Protonic acid doping of the emeraldine form to the metallic regime

Cited by 1,911 publications

References 23 publications

Spectroelectrochemical study of the oxidation of diaminophenols on platinum electrodes in acidic medium

Spectroelectrochemical study of the oxidation of diaminophenols on platinum electrodes in acidic medium

Polymerization of aniline under various concentrations of APS and HCl

Spectroscopic Investigation of Onset and Enhancement of Electrical Conductivity in PVC/PANI Composites and Blends by γ-ray or UV Irradiation

Contact Info

Product

Resources

About