scholarly journals Electrochemical synthesis of poly(2-methyl aniline): electrochemical and spectroscopic characterization

2001 ◽  
Vol 66 (1) ◽  
pp. 27-37 ◽  
Author(s):  
Aleksandra Buzarovska ◽  
Irena Arsova ◽  
Ljubomir Arsov
Keyword(s):  
Raman Spectroscopy ◽  
Cyclic Voltammetry ◽  
Redox Reactions ◽  
Electrochemical Polymerization ◽  
Spectroscopic Characterization ◽  
Potential Range ◽  
Cyclic Voltammograms ◽  
Impedance Measurements ◽  
Order Of Magnitude ◽  
Poly Aniline

Poly(2-methyl aniline) or poly(ortho-toluidine), as ring substituted derivative of aniline, has been synthesized electrochemically in various concentrations of H2SO4 and HCl, and then characterized by cyclic voltammetry, as well as by impedance and Raman spectroscopy. The cyclic voltammograms of poly(o-toluidine) and poly(aniline) show that the electrochemical polymerization of these two polymers proceeds by almost identical mechanisms. The Raman spectroscopical measurements suggest that the redox reactions of poly(aniline) and poly(o-toluidine) are similar in the potential range between -0.2 and 0.7V vs. SCE. The impedance measurements showed that the conductivity of poly(o-toluidine) is an order of magnitude lower than that of the corresponding poly(aniline) form.

Polyaniline: Influence of Polymerization Current Density

1994 ◽  
Vol 369 ◽  
Author(s):  
Steen Skaarup ◽  
L.M.W.K. Gunaratne ◽  
Keld West ◽  
Birgit Zachau-Christiansen
Keyword(s):  
Cyclic Voltammetry ◽  
Current Density ◽  
High Current Density ◽  
Electrochemical Polymerization ◽  
Regular Structure ◽  
Spectral Lines ◽  
Complex Nature ◽  
Cyclic Voltammograms ◽  
Layer By Layer ◽  
Current Densities

AbstractPolyaniline has been synthesized in propylene carbonate by galvanostatic electrochemical polymerization at current densities between 16 and 1000 μA/cm2. Earlier results for polypyrrole have shown that low and high current density films have different properties: The films synthesized at low current density have a higher conjugation length and a more regular structure. The corresponding effect in PANI has been investigated by cyclic voltammetry and UV/visible spectroscopy. Simultaneous measurement of cyclic voltammograms and the absorbtion of selected spectral lines is used because of the complex nature of the PANI system which involves several redox systems as well as forms differing in the degree of protonation and morphology.The main result is that the method of galvanostatic synthesis at low current densities (-16 μA/cm2) produces polyaniline polymers of different, more conjugated and more regular structure than those prepared at higher current densities. The standard method of in situ layer-by-layer polymerization of conducting polymers during cyclic voltammetry often results in uncontrolled and unmeasured current densities of 0.5-2 mA/cm2 which produces a film that probably has a less regular structure containing more deviations from ideality.

Supramolecular hetero-porphyrin SWNT complexes

2011 ◽  
Vol 15 (04) ◽  
pp. 257-263 ◽  
Author(s):  
Ashley Brewer ◽  
Matthew Lacey ◽  
John R. Owen ◽  
Iris Nandhakumar ◽  
Eugen Stulz
Keyword(s):  
Carbon Nanotubes ◽  
Raman Spectroscopy ◽  
Cyclic Voltammetry ◽  
Elemental Analysis ◽  
Single Walled Carbon Nanotubes ◽  
High Adsorption ◽  
Single Walled Carbon ◽  
Order Of Magnitude ◽  
Walled Carbon Nanotubes

The complexation of single walled carbon nanotubes (SWNTs) with neutral, anionic and cationic porphyrins has been investigated under identical complex forming conditions. The determination of the porphyrin loading reveals large differences depending on the nature of the porphyrin used. Combinations of different porphyrins to form mixed hetero-porphyrin complexes shows that the mixture of a cationic and anionic porphyrin results in loading which is an order of magnitude larger than in all other complexes. This complex also exhibits high adsorption and emission intensities and can be regarded as an extended co-operative binary ionic (CBI) solid. The complexes were further studied using Raman spectroscopy, elemental analysis, AFM and cyclic voltammetry.

Effect of Electrochemical Synthesis Conditions on Capacitor Performance of Polyaniline Electrodes

2012 ◽  
Vol 560-561 ◽  
pp. 488-493
Author(s):  
Hua Wang
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Impedance ◽  
Electrochemical Polymerization ◽  
Monomer Concentration ◽  
Potential Range ◽  
Aniline Monomer ◽  
Doping Agent ◽  
Electrochemical Impedance Spectra ◽  
Cycle Number ◽  
Synthesis Conditions

Abstract: Polyaniline was electrochemically synthesized on stainless steel using sulfuric acid as the doping agent through cyclic voltammetry. The influences of the aniline monomer concentration and cycle number on electrochemical performance were investigated by cyclic voltammetry and the electrochemical impedance spectra. The results show that increasing aniline concentration leads to the increase of aniline electrochemical polymerization rate. The mass specific capacitance of polyaniline electrode increases with the increase of aniline concentration for 10 cycles and it reaches 769.55 F/g at the aniline concentration of 0.3mol/L. However, the capacitances of polyaniline prepared at different aniline concentrations display no apparent differences for 15 or 20 cycles. Furthermore, the capacitance decreases with the increase of cycling number. Electrochemical impedance spectroscopes show that the polyaniline keeps superior conducting performance in the potential range of 0.1V~0.4V

scholarly journals Screening Potential of Electrogenic Algae for Bio Power Production from Aquatic Habitats of Tamil Nadu

2021 ◽  
Vol 108 (june) ◽  
pp. 1-5
Author(s):  
Sikkandhar Wasimraja ◽  
◽  
Subburamu Karthikeyan ◽  
Kalyanasundaram Geetha Thanuja ◽  
◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Transport Process ◽  
Tamil Nadu ◽  
Power Production ◽  
Potential Range ◽  
Cyclic Voltammograms ◽  
Oxidation Peak ◽  
Aquatic Habitats ◽  
Anaerobic Conditions ◽  
Extracellular Electron Transport

This paper illustrates the potential ofmicroalgae in electricity production.The present study focuses on searching for, indigenous microalgal strains from various aquatic sources exhibiting electrogenic activity. Sixteen microalgal strains were obtained from the diverse water bodies and assessed for electron transfer ability between cell and electrode. Six algal strains were screened out of eighteen for potential electrogenicity, based on cyclic voltammetry assay. In contrast to other algal strains, the cyclic voltammograms of Hindakia sp. isolated from paddy fields displayed an oxidation peak under anaerobic conditions in the potential range of +100 to +200 mV, while no distinct peaks were observed in other strains. This research broadened the exoelectrogen and identified model microalgae for investigating the extracellular electron transport process.

Self-assembled molecular films of tetraamino metal (Co, Cu, Fe) phthalocyanines on gold and silver. Electrochemical and spectroscopic characterization

2002 ◽  
Vol 74 (9) ◽  
pp. 1609-1620 ◽  
Author(s):  
M. P. Somashekarappa ◽  
J. Keshavayya ◽  
S. Sampath
Keyword(s):  
Cyclic Voltammetry ◽  
Spectroscopic Characterization ◽  
Redox Couple ◽  
Cobalt Phthalocyanine ◽  
Molecular Films ◽  
Complete Coverage ◽  
Metal Phthalocyanines ◽  
Impedance Measurements ◽  
Ft Raman Spectroscopy ◽  
Ft Raman

The formation of molecular films of 2,9,16,23-tetraamino metal phthalocyanines [TAM(II)Pc; M (II) = Co, Cu, and TAM(III)Pc; M = Fe] by spontaneous adsorption on gold and silver surfaces is described. The properties of these films have been investigated by cyclic voltammetry, impedance, and FT-Raman spectroscopy. The charge associated with Co(II) and Co(I) redox couple in voltammetric data leads to a coverage of (0.35 ± 0.05) x 10-10 mol cm-2, suggesting that the tetraamino cobalt phthalocyanine is adsorbed as a monolayer with an almost complete coverage. The blocking behavior of the films toward oxygen and Fe(CN)63-/4- redox couple have been followed by cyclic voltammetry and impedance measurements. This leads to an estimate of the coverage of about 85% in the case of copper and the iron analogs. FT-Raman studies show characteristic bands around 236 cm-1 revealing the interaction between the metal substrate and the nitrogen of the -NH2 group on the phthalocyanine molecules.

scholarly journals Ultralong π-Conjugated Bis(terpyridine)metal Polymer Wires Covalently Bound to a Carbon Electrode: Fast Redox Conduction and Redox Diode Characteristics

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4267
Author(s):  
Kuo-Hui Wu ◽  
Ryota Sakamoto ◽  
Hiroaki Maeda ◽  
Eunice Jia Han Phua ◽  
Hiroshi Nishihara
Keyword(s):  
Metal Complex ◽  
Electrochemical Method ◽  
Redox Reactions ◽  
Cyclic Voltammograms ◽  
Wire Arrays ◽  
Reversible Redox ◽  
Complex Linear ◽  
Complex Polymer ◽  
Metal Polymer ◽  
Hclo4 Solution

We developed an efficient and convenient electrochemical method to synthesize π-conjugated redox metal-complex linear polymer wires composed of azobenzene-bridged bis(terpyridine)metal (2-M, M = Fe, Ru) units covalently immobilized on glassy carbon (GC). Polymerization proceeds by electrochemical oxidation of bis(4′-(4-anilino)-2,2′:6′,2″-terpyridine)metal (1-M) in a water–acetonitrile–HClO4 solution, affording ultralong wires up to 7400 mers (corresponding to ca. 15 μm). Both 2-Fe and 2-Ru undergo reversible redox reactions, and their redox behaviors indicate remarkably fast redox conduction. Anisotropic hetero-metal-complex polymer wires with Fe and Ru centers are constructed via stepwise electropolymerization. The cyclic voltammograms of two hetero-metal-complex polymer wires, GC/[2-Fe]–[2-Ru] (3) and GC/[2-Ru]–[2-Fe] (4), show irreversible redox reactions with opposite electron transfer characteristics, indicating redox diodelike behavior. In short, the present electrochemical method is useful to synthesize polymer wire arrays and to integrate functional molecules on carbon.

Cyclic Voltammetry, Impedance Measurements and In-Situ EPR Studies of Conjugated Polymers

1991 ◽  
Vol 21 ◽  
pp. 139-162 ◽  
Author(s):  
L. Wuckel ◽  
M. Schwarzenberg ◽  
A. Bartl ◽  
H.G. Döge
Keyword(s):  
Cyclic Voltammetry ◽  
Conjugated Polymers ◽  
Impedance Measurements

Real-time size tuning and measuring of silver nanoparticles by cyclic voltammetry and Raman spectroscopy

2021 ◽  
pp. 131420
Author(s):  
Shuo Wang ◽  
Xin Yan ◽  
Min Zhang ◽  
Gang Dong ◽  
Ramiro Moro ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Silver Nanoparticles ◽  
Cyclic Voltammetry ◽  
Real Time

scholarly journals Investigations on the Redox Characteristics and Hydrogen Evolution Efficiencies of Pd and Mo Deposited Pd Electrodes in Alkaline Electrolyte

1970 ◽  
Vol 43 (1) ◽  
pp. 103-116 ◽  
Author(s):  
M Ashraful Islam Molla ◽  
Mithun Sarker ◽  
AKM Fazle Kibria
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Adsorption ◽  
Stable Condition ◽  
Alkaline Electrolyte ◽  
Potential Range ◽  
Cyclic Voltammograms ◽  
Absorption Region ◽  
Potential Value ◽  
Density Values ◽  
Hydrogen Evolution Reactions

Redox behaviors and hydrogen evolution efficiencies of Pd and Mo deposited Pd electrodes have been investigated in 30wt.% KOH electrolyte by cyclic voltammetry. Cyclic voltammograms of Pd electrode in between the potential range - 1.05 V to + 0.75 V showed two couples of redox peaks for the transformations of Pd(0) ←→ Pd(OH)2 and Pd(OH)2 ←→ PdOOH, an anodic peak for the desorption of diffusional hydrogen (dH) and hydrogen and oxygen evolutions at the terminal potential regions. Hydrogen evolution efficiency found decreased with time and then reached to a stable condition after 35 minutes. In presence of deposited Mo, the electrode stable condition appeared after 10 minutes only. Pd found predominates over deposited Mo. Both the Pd(0) ←Pd(OH)2 and Mo(0) ← Mo(OH)2 transformations appeared at the same potential value. Mo stopped the movement of hydrogen adsorption and absorption region of Pd electrode towards negative potential direction. It increased the hydrogen evolution efficiency of Pd electrode remarkably. At the potentials - 1.1 V, - 1.2 V, - 1.25 V and - 1.3 V, currents for Pd + Mo system found 1.44, 1.25, 1.20, 1.23 times higher than those of Pd electrode. Mo also showed hydrogen migratory role to the fraction of Pd surface covered by it. Hydrogen evolution reactions (HER) over Pd and Pd + Mo surfaces seemed followed similar mechanisms. Tafel plots for the HER for both the systems showed two Tafel regions. Exchange current density values (io) for the low and high overpotential regions of Pd + Mo system showed 2.85 times and 1.29 times higher values than those of Pd electrode. Key words: Pd, Pd-Mo, Hydrogen evolution efficiency, Hydrogen evolution reactions (HER) DOI: 10.3329.bjsir.v43i1.861 Bangladesh J. Sci. Ind. Res. 43(1), 103-116, 2008

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