Polyaniline (PANI) enzyme electrode was formed by immobilisation of Glucose oxidase (GOx) via glutaraldehyde into electrochemically polymerised PANI on graphite electrode. Electrochemical ...polymerisation of PANI on graphite was performed from aqueous solution of 1.0
mol
dm
−3 HCl and 0.25
mol
dm
−3 aniline at constant current density of 2.0
mA
cm
−2. Hronopotentiometric curves of the PANI enzyme electrode obtained at current density of 10
μA
cm
−2 were recorded in different glucose concentrations. The linearity response range was between 1.0 and 5.0
mmol
dm
−3 of glucose concentration. The estimated apparent Michaelis–Menten constant, was
K
m
′
=
0.30
mmol
dm
−3, which is significantly lower than that of free enzyme.
•Polyaniline in the form of base and salt was prepared chemically and electrochemically.•Corrosion of mild steel with different composite coatings were investigated.•Chemically prepared emeraldine ...salt posses good anticorrosion properties.•Anticorrosion properties were connected with the content of oligomers in the samples.•It was proposed that polyaniline acts as active barriers.
The protective abilities of composite coatings based on electrochemically and chemically formed polyaniline powder against the corrosion of mild steel were investigated. A polyaniline powder has been prepared in the form of an emeraldine base and benzoate salt through chemical dedoping and doping. The composite coatings using polyaniline powders, which were obtained through different routes, and base coatings, which were not corrosion-resistant, with different formulations were prepared and applied on mild steel samples. The corrosion was investigated using an electrochemical impedance technique in 3% NaCl, and the atmospheric corrosion was assessed in a humidity chamber. Emeraldine–benzoate salts, which are a chemically synthesized polyaniline, offer the best protection with an optimal polyaniline concentration of approximately 5wt%. The different corrosion behaviors were assessed relative to the presence of aniline oligomers in the samples after characterization using UV–vis spectrophotometry. Upon comparison between the corrosion behavior in 3% NaCl with commercial primer paint for iron and that with a paint containing 5wt% PANI, the composite coating has superior anticorrosion characteristics. The mechanism for the protection of mild steel from corrosion through composite polyaniline coatings was also considered.
Polypyrrole (PPy) thin film electrode was galvanostatically synthesized and characterized in 0.1
M HCl on graphite electrode as cathode materials for the aqueous-based rechargeable zinc batteries. ...The charge/discharge characteristics of PPy and zinc electrode in 0.1
M ammonium chloride and in the 0.1
M ammonium chloride with addition of 0.1
M sodium citrate were investigated. Electrochemical characteristic of possible Zn|PPy cell in chloride/citrate containing electrolyte was discussed and simulated.
Zinc Polypyrrole-air Sea Water Battery Al-Eggiely, A.H.; Alguail, A.A.; Gvozdenović, M.M. ...
International journal of electrochemical science,
12/2016, Letnik:
11, Številka:
12
Journal Article
Recenzirano
Odprti dostop
An environmentally friendly cell using polypyrrole-air regenerative cathode and zinc as anode, is investigated in the 3.5% sodium chloride solution for the possible applications as the sea water ...cell. It is shown that cell can deliver constant current in the range of tens of milliamps per gram of polypyrrole, and in the range of hundreds of milliamps under impulse discharge mod, with the cell voltage above 0.8 V, over significant period of time. It is suggested that cell could be considered, at least as a secondary power in a remote sensor buoy system for the monitoring shallow marine environments.
Electrochemically formed thin film polyaniline (PANI) anode and lead dioxide (PbO
2) cathode, obtained from sulfuric acid solution, for potential applications as electrode materials in PANI|H
2SO
...4|PbO
2 aqueous based rechargeable power sources, have been studied using cyclic voltammetry and galvanostatic techniques. Based on the investigations of half cell reactions, the simulation of the charge/discharge characteristic of the possible cell has been done.
Electrochemical behavior of zinc and polyaniline (PANI) electrode polymerized from 0.1
M HCl and 0.1
M aniline on graphite electrode, in 0.2
M ZnCl
2 and 0.50
M NH
4Cl (chloride electrolyte) and with ...addition of 0.33
M Na-citrate (chloride/citrate electrolyte) were investigated. In the chloride/citrate comparing with chloride containing electrolyte for the zinc electrode negative shift of the open circuit potential of 150
mV, decreases of exchange current density for more than order of magnitude and increase of cathodic Tafel slope, due to the zinc ions complexation, were observed. In citrate/chloride electrolyte zinc dendrite formation were completely suppressed. PANI electrodes show better discharge characteristic in chloride/citrate electrolyte with determined maximum discharge capacity of 164
mAh
g
−1.
Electrochemical behavior of zinc and thin polyaniline (PANI) polymerized from 0.1
M HCl to 0.1
M aniline on graphite electrode, in 0.2
M ZnCl
2 and 0.50
M NH
4Cl (chloride electrolyte) and with ...addition of 0.33
M Na-citrate (chloride/citrate electrolyte) were investigated. In the chloride/citrate comparing with chloride containing electrolyte zinc electrode shows negative shift of the open circuit potential of ∼130
mV, decreases of exchange current density for more than order of magnitude and increase of cathodic Tafel slope, due to the zinc ions complexation. In citrate/chloride electrolyte zinc dendrite formation were suppressed. In the range of investigated charge/discharge current densities of 0.25–1
mA
cm
−2, initially obtained specific capacity was in the range of 140–85
mAh
g
−1, respectively. In cycling regime specific capacity and columbic efficiency were affected with anodic potential limits. For anodic potential limits of 0.32
V (SCE) citrate/chloride electrolyte shows better characteristic than chloride electrolyte, due to the influence of citrate ions on negative shift of doping reaction. Increasing anodic potential limit to 0.5
V (SCE), leads to faster decrease of specific capacity in citrate/chloride than in chloride electrolyte, which was. explained by higher hydrophilic effect of citrate anions.
Electrochemical polymerization of polyaniline (PANI) coating on copper electrode was performed galvanostatically in the current density range between 0.50 and 1.25
mA
cm
−2, from aqueous solution of ...0.3
mol
dm
−3 sodium benzoate and 0.2
mol
dm
−3 aniline. The corrosion behavior of PANI coated copper and copper electrode exposed to 0.5
mol
dm
−3 sodium chloride solution was investigated by potentiodynamic and electrochemical impedance spectroscopy techniques. It was observed that thin PANI (5
μm) coating had provided efficient protection (∼96%) to copper in 0.5
mol
dm
−3 sodium chloride solution. Unusual initial impedance behavior to that normally observed with conventional organic coatings was attributed to dedoping of benzoate anions from the polymer coating.
Polyaniline electrode (PANI) was formed electrochemically at graphite electrode. Electrochemical polymerization was performed at constant current density of 2.0
mA
cm
−2 from aqueous solution of 1.0
...mol
dm
−3 HCl with addition of 0.25
mol
dm
−3 aniline monomer. Electrochemical characterization of the PANI electrode in chloride and chloride/citrate electrolyte was performed using cyclic voltammetry and galvanostatic measurement in order to study the influence of citrate ions on charge/discharge capability and cycling efficiency. It was observed that, for anodic potential 0.32
V, higher electrode capacity of PANI electrode in chloride/citrate electrolyte was obtained, comparing to chloride electrolyte, indicating positive effect of citrate ions on cycling characteristics. On the other hand, for higher anodic potential limit of 0.50
V, faster decrease of the electrode capacity in chloride/citrate electrolyte was observed. It was suggested that influence of both chloride and citrate anions had exhibited influence on electrochemical behavior of PANI electrode in citrate containing electrolyte.
Electrochemical oxidation of iodide on DSA (Ti/RuO
2) anode was investigated in laboratory cell and semi-industrial electrochemical reactor. Anodic polarization curves in the laboratory cell were ...obtained in solutions contained 0.10, 0.25 and 0.40
mol
dm
−3 KI in order to determined current densities for electrolysis in the semi-industrial electrochemical reactor. Parameters of the electrolysis were estimated using semi-industrial electrochemical reactor in which concentration of KI and current density were varied. pH and reactor voltage, were measured as a function of time, as well. The electrolysis was carried out until stationary concentration of equivalent iodine was reached. It was concluded that optimal electrolysis conditions based on current efficiency, concentrations of equivalent iodine, and the other parameters, was achieved in solution contained 0.40
mol
dm
−3 KI and with current density of 10
mA
cm
−2. Based on the theoretical analysis of the iodine–iodide–water equilibria, it was concluded that at pH 11.6 main electrolysis products were triiodide, hypoiodite and IOH
2
−.
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