Polyaniline electrochemical properties

Electronically conducting polymers (ECPs) such as polyaniline (PANI), polypyrrole (PPy) and po 1 y(3.4-cthy 1 cncdi oxyth iophcnc) (PEDOT) have been applied in supercapacitors, due to their excellent electrochemical properties and lower cost than other ECPs. We demonstrated that multi-walled carbon nanotubes (CNTs) prepared by catalytic decomposition of acetylene in a solid solution are very effective conductivity additives in composite materials based on ECPs. In this paper, we show that a successful application of ECPs in supercapacitor technologies could be possible only in an asymmetric configuration, i.e. with electrodes of different nature. 

Nabid MR, Golbabaee M, Moghaddam AB, Dinarvand R, Sedghi R (2008) Polyaniline/Ti02 nanocomposite enzymatic synthesis and electrochemical properties. Int J Electrochem Sci 3(10) 1117-1126... 

Kuwabata etal. [161] have prepared, via electrochemical polymerization on Au(lll), SAMs comprising aminoben-zenethiol and 3-aminophenethylthiol units. Polymerization of aminoben-zenethiol required the use of ortho and meta isomers in the molar ratio of 1 1, whereas, in contrast, 3-amino-phenethylthiol was easily polymerized as a pure substance. The monolayers obtained exhibited electrochemical properties very similar to those of polyaniline and their derivatives. 

A few other types of anion sensors have been mentioned recently in the literature. Tetrathiofulvalene microcrystals immobilised at a platinum electrode displayed electrochemical properties that were affected by the presence of anions in solution, with some selectivity for anions such as bromide [ 145]. A flow-injection analysis system using anion-exchange columns for separation and polyaniline electrodes as detectors could detect dichromate down to 0.004 ppb and could be used for seawater samples [146]. 

Electro-oxidation of diphenylamine systems has received extensive attention. Recent interest has been associated with the preparation of electronically conductive polymers, such as polyaniline. An important role of p-aminodiphenylamine in the anodic oxidation of aniline is well documented and therefore fundamental electrochemical properties... 

For molybdenum and arsenic oxides [1—3], it has been shown that the modification of the oxide surface by adsorption of a conducting polymer (polyaniline, in these cases) can exert remarkable effects on the electrochemical properties of the oxides. 

B. K. Kuila, B. Nandan, M. Bohme, A. Janke, and M. Stamm, Vertically oriented arrays of polyaniline nanorods and their super electrochemical properties, Chem. Commun., 38, 5749-5751 (2009). 

S. Tian, J. liu, T. Zhu, and W. KnoU, Polyaniline doped with modified gold nanoparticles and its electrochemical properties in neutral aqueous solution, Chem. Commun., 2738 739 (2003). 

X. Yu, Y. Li, and K. Kalantar-zadeh, Synthesis and electrochemical properties of template-based polyaniline nanowires and template-free nanofibril arrays Two potential nanostructures for gas sensors, Sens. Actuat. B, 136, 1-7 (2009). 

D.D. Pra and S.D. Champagne, A comparative study of the electronic structure and spectro-electrochemical properties of electrosynthesized polyaniline films and nanotubes. Thin Solid Films, 479, 321 328 (2005). 

The unique transport characteristics of conducting polymer membranes that we have demonstrated arise from their electrochemical properties. For the purpose of this discussion polypyrroles will be used, however, similar principles apply to transport across polyaniline membranes. 

Zhou, H.H., S.Q. Jiao, J.H. Chen, W.Z. Wei, and Y.F. Kuang. 2004. Relationship between preparation conditions, morphology and electrochemical properties of polyaniline prepared by pulse galvanostatic method (PGM). Thin Solid Films 450 (2) 233-239. 

Similar to the PB-conducting polymer composites, composite films can be prepared with conducting polymers and transition metal oxides. Composite films have been prepared by the electrostatic layer-by-layer technique with polyaniline and vanadium oxide with the electrochemical properties dominated by the vanadium oxide layers and the optical properties dominated by the polyaniline layers [245,246]. Composites have also been made between the water-soluble poly(2-(3-thienyloxy)ethanesulfonic acid) and vanadium oxide by mixing the two materials at different mole ratios in aqueous solutions. These films switched between an orange color when fully reduced, to yellow-green at intermediate potentials, and to dark blue when fully oxidized [247]. 

Huguenin, E, M. Ferreira, V. Zucolotto, EC. Nart, R.M. Torresi, and O.N. Oliveira, Jr. 2004. Molecular-level manipulation of V205/polyaniline layer-by-layer films to control electrochromo-genic and electrochemical properties. Chem Mater 16 2293-2299. 

The most elegant approach to design polypyrrole, polyaniline or polythiophene-based porphyrin, phthalocyanine or Schiff base matrices involves the electrochemical polymerization of suitably designed substituted N4-macrocyclic monomers. We and others have shown that the electro-oxidative polymerization of such species (see significant examples in Figure 8.3) leads to the formation of films having the electrochemical properties of the monomeric complex" . ... 

For improving the energy storage efficiency, ECP/CNM nanocomposites are widely used in electrochemical energy storage devices. These include lithium-ion batteries and supercapacitors. Polyaniline/CNM nanocomposites and polypyrrole/CNM nanocomposites are the major composite nanostructures used for this piupose due to their superior electrochemical properties, low cost and easy processing methods. 

Supercapacitors require electrode materials that have good electrical conductivity, good electrochemical properties, high chemical and environmental stabilities, etc. Various ECP/CNM nanocomposites such as polyaniline/carbon nanofiber [31,32,34], polyaniline/graphene [62,67-69], and polypyrrole/graphene [73,75] are widely used as electrode materials in supercapacitors. 

FeSj/polyaniline (PANI) composite as cathode material for LIB was synthesized via in-situ chemical polymerization of aniline in the presence of fine FeS particles in aqueous suspension. The FeS /PANI composite exhibited the capacity of 767.5 mAh/g at a current density of 100 mA/g with weaker polarization and improved reversible capacity, compared with the FeSj particle. The improvement of the electrochemical properties was due to the enhanced electrical conduction and the buffer connection of amorphous polymer between the particles of the composite [56]. 

Y. K. Kang, M. H. Lee, S. B. Rhee, Electrochemical properties of polyaniline doped with poly(styrenesulfonic acid), Synthetic Metals 1992, 52, 319. 

S. Kim, I. J. Chung, Annealing effect on the electrochemical property of polyaniline complexed with various acids, Synthetic Metals 1998, 97, 127. 

C. Barhero, M. C. Miras, R. Kotz, O. Haas, Comparative study of the ion-exchange and electrochemical properties of sulfonated polyaniline (SPAN) and polyaniline (PANi), Synthetic Metals 1993, 55, 1539. 

Doh CH et al (2006) Synthesis of silicon-carhon by polyaniline coating and electrochemical properties of the Si-C vertical bar Li cell. Bull Korean Chem Soc 27 1175-1180... 

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