01626nas a2200181 4500008004100000022001400041245008200055210006900137260007100206300001600277490000800293520094700301100002301248700002101271700002201292700001801314856011201332 2008 eng d a1520-610600aAdsorption of sulfonated dyes by polyaniline emeraldine salt and its kinetics0 aAdsorption of sulfonated dyes by polyaniline emeraldine salt and a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcAUG a10153-101570 v1123 a

A method for the removal of anionic (sulfonated) dyes from aqueous dye solutions using the chemical interaction of dye molecules with polyaniline is reported. Polyaniline (PANI) emeraldine salt was synthesized by chemical oxidation. Sulfonated dyes undergo chemical interactions with the charged backbone of PANI, leading to significant adsorption of the dyes. This phenomenon of selective adsorption of the dyes by PANI is reported for the first time and promises a green method for removal of sulfonated organics from wastewater. The experimental observations from UV-vis spectroscopy, X-ray diffraction, and conductivity measurements rule out the possibility of secondary doping of polyaniline salt by sulfonated dye molecules. A possible mechanism for the chemical interaction between the polymer and the sulfortated dye molecules is proposed. The kinetic parameters for the adsorption of sulfonated dyes on PANI are also reported.

1 aMahanta, Debajyoti1 aMadras, Giridhar1 aRadhakrishnan, S.1 aPatil, Satish uhttp://library.ncl.res.in/content/adsorption-sulfonated-dyes-polyaniline-emeraldine-salt-and-its-kinetics-001456nas a2200181 4500008004100000022001400041245007600055210006900131260007100200300001400271490000800285520079100293100002301084700002101107700002201128700001801150856010601168 2009 eng d a1520-610600aAdsorption and desorption kinetics of anionic dyes on doped polyaniline0 aAdsorption and desorption kinetics of anionic dyes on doped poly a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcFEB a2293-22990 v1133 a

In this study, we report an approach for the adsorption and desorption of anionic (sulfonated) dyes from aqueous solution by doped polyaniline. In this study, we have synthesized PANI with two dopants, namely, p-toluenesulfonic acid (PTSA) and camphorsulfonic acid (CSA), and used these to adsorb various dyes. It was found that the doped PANI selectively adsorbs anionic dyes and does not adsorb cationic dyes. The adsorption of anionic dyes causes the variation in electrical conductivity of PANI, indicating its potential as a conductometric sensor for these dyes at very low concentration. The adsorbed dyes were desorbed from the polymer by using a basic aqueous solution. The adsorption and desorption kinetics of the dye in the presence of doped PANI were also determined.

1 aMahanta, Debajyoti1 aMadras, Giridhar1 aRadhakrishnan, S.1 aPatil, Satish uhttp://library.ncl.res.in/content/adsorption-and-desorption-kinetics-anionic-dyes-doped-polyaniline-002257nas a2200253 4500008004100000022001400041245008700055210006900142260010600211300001400317490000700331520135200338653001801690653001201708653002301720653001901743653002101762100002201783700001701805700002301822700001801845700002101863856011901884 2009 eng d a0013-468600aConducting polyaniline-nano-TiO2 composites for smart corrosion resistant coatings0 aConducting polyanilinenanoTiO2 composites for smart corrosion re aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcJAN a1249-12540 v543 a

Coatings prepared from polyaniline-nano-TiO2 particles synthesized by in situ polymerization were found to exhibit excellent corrosion resistance much superior to polyaniline (PANI) in aggressive environments. The corrosion Studies were carried out on steel plates coated with these formulations containing 10 wt% polyaniline prepared with different concentrations of nano-TiO2. The electrochemical impedance spectroscopy was studied at periodic intervals during exposure to hot saline (65 degrees C) conditions for prolonged durations over a period of 90 h. The open circuit potential (OCP) was found to shift with time from -0.38 V SCE to more anodic side (-0.2 V SCE) much above that of bare steel (-0.5 VSCE). The presence of nano-TiO2 was found to be vital in the prevention of corrosion and the shift of OCP to anodic side. From these data, one could envisage more than 100 times improvement in the corrosion resistance especially for polyaniline prepared with 4.18 wt% nano-TiO2. The exceptional improvement of performance of these coatings has been associated with the increase in barrier to diffusion, prevention of charge transport by the nanosize TiO2, redox properties of polyaniline as well as very large surface area available for the liberation of dopant due to nano-size additive. (C) 2008 Elsevier Ltd. All rights reserved.

10aAnticorrosion10aCoating10aconducting polymer10aNano-composite10aTitanium dioxide1 aRadhakrishnan, S.1 aSiju, C., R.1 aMahanta, Debajyoti1 aPatil, Satish1 aMadras, Giridhar uhttp://library.ncl.res.in/content/conducting-polyaniline-nano-tio2-composites-smart-corrosion-resistant-coatings-001965nas a2200241 4500008004100000022001400041245005800055210005800113260006900171300001200240490000800252520118600260653002701446653002001473653002001493653001601513100002301529700002301552700002201575700002101597700001801618856008701636 2011 eng d a0379-677900aPolyaniline modified electrodes for detection of dyes0 aPolyaniline modified electrodes for detection of dyes aPO BOX 564, 1001 LAUSANNE, SWITZERLANDbELSEVIER SCIENCE SAcMAY a659-6640 v1613 a

Polyaniline (PANI) is one of the most extensively used conjugated polymers in the design of electrochemical sensors. In this study, we report electrochemical dye detection based on PANI for the adsorption of both anionic and cationic dyes from solution. The inherent property of PANI to adsorb dyes has been explored for the development of electrochemical detection of dye in solution. The PANI film was grown on electrode via electrochemical polymerization. The as grown PANI film could easily adsorb the dye in the electrolyte solution and form an insulating layer on the PANI coated electrode. As a result, the current intensity of the PANI film was significantly altered. Furthermore, PANI coated stainless steel (SS) electrodes show a change in the current intensity of Fe(2+)/Fe(3+) redox peaks due to the addition of dye in electrolyte solution. PANI films coated on both Pt electrodes and non-expensive SS electrodes showed the concentration of dye adsorbed is directly proportional to the current intensity or potential shift and thus can be used for the quantitative detection of textile dyes at very low concentrations. (C) 2011 Elsevier B.V. All rights reserved.

10aElectrochemical sensor10aEmeraldine base10aEmeraldine salt10apolyaniline1 aMahanta, Debajyoti1 aMunichandraiah, N.1 aRadhakrishnan, S.1 aMadras, Giridhar1 aPatil, Satish uhttp://library.ncl.res.in/content/polyaniline-modified-electrodes-detection-dyes-0