Conducting polymers polyaniline

The monomer of the conducting polymer polyaniline is the compound aniline (aminobenzene). (a) Draw the structural formula of the aniline monomer. What is the hybridization of the N atom in (b) aniline (c) polyaniline (d) Indicate the locations of lone pairs, if any, in polyaniline, (e) Do the N atoms help to carry the current Explain your reasoning. See Box 19.1. 

Numerous workers126-132 have combined PB with the conducting polymer polyaniline in complementary ECDs that exhibit deep blue-to-light green electrochromism. Electrochromic compatibility is obtained by combining the colored oxidized state of the polymer1 with the blue PB, and the bleached reduced state of the polymer with PG (Equation (17)) ... 

Conducting polymers, polyaniline, catalytic activity, PANI/expanded graphite composites, metal-air batteries, primary rechargeable cells. 

Transition metal compounds, such as organic macrocycles, are known to be good electrocatalysts for oxygen reduction. Furthermore, they are inactive for alcohol oxidation. Different phthalocyanines and porphyrins of iron and cobalt were thus dispersed in an electron-conducting polymer (polyaniline, polypyrrole) acting as a conducting matrix, either in the form of a tetrasulfonated counter anion or linked to... 

As a conducting polymer, polyaniline has many electronics-related applications, such as rechargeable batteries (Tsutsumi et al. 1995), multilayer heterostructure light-emitting diode devices (Onoda Yoshino 1995), biosensors (Bartlett Whitaker 1987), elec-trochromic windows (Nguyen Dao 1989), and nonlinear optical materials (Papacostadi-nou Theophilou 1991). Polyaniline may be prepared from aniline by both electrochemi-... 

The signal travels through a thick, or even molecularly thin, semiconductor that connects these electrodes it could be an inorganic semiconductor (doped Si, doped Ge), an organic conducting polymer (polyaniline, polythiophene, polyacetylene), a carbon nanotube, or an organic semiconductor (sexithiophene). 

The formation of -aminodiphenylamine is supposed to be the key intermediate in the formation of a dark green precipitate at the electrode surface during continued electrolysis of acidic aniline solutions. This has been characterized as an oligomer of aniline, for example, as the octamer emeraldine formed by a cascade of head-to-tail condensations [38,39]. Nelson, however, explained it as a mixture of mainly quinhydrone with a small amount of benzidine salt [37]. Today the electropolymerization of aniline under strongly acidic conditions is intensively studied as an important way to form the conducting polymer polyaniline [40] (see Chapters 31 and 32). 

Different electron-conducting polymers (polyaniline, polypyrrole, polythiophene) are considered as convenient substrates for the electrodeposition of highly dispersed metal electrocatalysts. The preparation and the characterization of electronconducting polymers modified by noble metal nanoparticles are first discussed. Then, their catalytic activities are presented for many important electrochemical reactions related to fuel cells oxygen reduction, hydrogen oxidation, oxidation of Cl molecules (formic acid, formaldehyde, methanol, carbon monoxide), and electrooxidation of alcohols and polyols. 

In addition to catalysis of small molecule transformations and biocatalysis, non-functionalized LLC phases used as reaction media have also been found to accelerate polymerization reactions as well. For example, the L and Hi phases of the sodium dodecylsulfate/n-pentanol/sulfuric acid system have been found to lower the electric potential needed to electropolymerize aniline to form the conducting polymer, polyaniline [110]. In this system, it was also found that the catalytic efficiency of the L phase was superior to that of the Hi phase. In addition to this work, the Ii, Hi, Qi, and L phases of non-charged Brij surfactants (i.e., oligo(ethylene oxide)-alkyl ether surfactants) have been observed to accelerate the rate of photo-initiated radical polymerization of acrylate monomers dissolved in the hydrophobic domains [111, 112]. The extent of polymerization rate acceleration was found to depend on the geometry of the LLC phase in these systems. Collectively, this body of work on catalysis with non-functionalized LLC phases indicates that LLC phase geometry and system composition have a large influence on reaction rate. 

This diol was mixed with other diols, then reacted with diisocyanates to form polyurethanes. The electrically conducting polymers, polyaniline and polypyrrole, prevent corrosion of steel.105 One of the best formulations uses polyaniline with zinc nitrate, which is then covered with an epoxy resin topcoat. Polyorganosiloxanes have been grafted to starch using the sol-gel method with alkoxysi-lanes. These materials have been complexed with cerium ions to provide corrosion protection for aircraft that is expected to be 50% cheaper than conventional coatings.106... 

As an environmentally stable conducting polymer, polyaniline has been recognized as a potential candidate for application in secondary battery electrodes, sensors, electrochromic display devices, microelectronics, ion-exchange resins etc. [151-161]. 

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. 

T.V. Shishkanova, P. Matejka, V. Krai, I. Sedenkova, M. Trchova, and J. Stejskal Optimization of the thickness of a conducting polymer, polyaniline, deposited on the surface of poly(vinyl chloride) membranes A new way to improve their potentiometric response. Anal. Chim. Acta, 624, 238-246 (2008). 

The book starts with an introductory chapter about conductive polymers. For those who are familiar with nanotechnology, this chapter is a guiding star and for polymer scientists, it is a reminder that from where we have started. The two next chapters are typical ones to introduce the realms of nanostructured conductive polymers. Polyaniline is considered as a prototype and among most popular conductive polymers. Chapter 3 discusses some interesting features in surface studies of conductive polymer, while surface analysis is always a key concept in the realm of nanotechnology. 

Henry Letheby, a lecturer in chemistry and toxicology at the College of London Hospital, obtained a partially conducting material in 1862 by the anodic oxidation of aniline in sulfuric acid. The material Letheby synthesized was a form of polyaniline. In the 1980s, the New Zealander Alan MacDiarmid of the University of Pennsylvania reinvestigated polyaniline, which is now a widely used conducting polymer. Polyaniline exists in a variety of oxidation states (Figure 27.12), each with different... 

B. Wessling, Dispersion as the Linkbetween Basic Research and Commercial Applications of Conductive Polymers (Polyaniline). Synth. Met. 1998, 93,... 

Keywords Thermoelectric power, Seebeck coefficient, thermal conductivity electrical conductivity power factor, figure of merit, intrinsically conducting polymers, polyaniline, polypyrrole, polythiophene, nanoparticles, graphene, carbon nanotubes (CNTs), hybrids, nanocomposites... 

Rakhi et al reported the conducting-polymers (polyaniline [PANI] and PPy)-coated carbon nanocoils (CNCs) as efficient binder-free electrode materials for supercapacitors for the first time, in which the CNCs acted as a perfect backbone for the uniform distribution of the conducting polymers in the composites [16]. Ihe SC and maximum storage energy per unit mass of the composites were found to be comparable to one of the best-reported values for polymer-coated MWNTs. Dumanli et al. prepared the chemically bonded carbon nanofibers (CNFs)-PPy composite via electro-polymerization of Py on CNFs [17]. It showed that the final capacitance values were highly dependent on the number of deposition cycles and deposition rates. The best result for the coiled CNF-PPy composite system was found to be 27.6 C/cm at six times cycling using 25 mV/s. 

Fibers containing intrinsically conductive polymer are manufactured from a composition containing an organic acid salt of an intrinsically conductive polymer, a matrix polymer, and a spinning solvent. Polyaniline is the intrinsically conductive polymer. Polyaniline alone cannot be processed into fiber because of its low solubility (standard wet spinning methods require a polymer concentration of 15-20%). Many polymers can be used as the matrix polymer. For this application, polyacrylonitrile was selected. A variety of solvents can be used but dimethylacetamide was found to be the most useful. 

Carbon-coated LiFePO (C-LFP) composites incorporated with electro-chemically active conducting polymer polyaniline (PANI) were fabricated in situ by chemical oxidative polymerization as cathode for LIB. Specific capacities as high as 165 mAh/g at 0.2 C, 133 mAh/g at 7 C and 123 mAh/g at 10 C were observed in C-LFP/7 wt% PANI composite. The improved cyclability as compared with the parent C-LFP was due to PANI, which acts not only as an additional host for Li -ion insertion/extraction, but also as a binder to modify the electrode surface and a container for electrolyte to penetrate into C-LFP particles [55]. 

C. Barbero, H. J. Salavagione, D. F. Acevedo, D. E. Grumelli, F. Garay, G. A. Planes, G. M. Morales, M. C. Miras, Novel synthetic methods to produce functionalized conducting polymers polyanilines, Electrochimica Acta 2004, 49, 3671. 

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