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Electrochemical oxidative polymerization of pyrrole on platinum electrode in acid medium was carried out. Different reaction parameters were investigated such as current density, acid concentration, monomer concentration, and temperature with duration of time. The orders of the electropolymerization reaction were found to be 1.3, 1.26, and 1.2 with respect to current density, acid concentration, and monomer concentration, respectively. The apparent activation energy was found to be 38.3 kJ mol Ϫ1 . The obtained polymer films were characterized by 1 H-NMR, elemental analysis, thermogravimetric analysis, and cyclic voltammetry. The mechanism of the electrochemical polymerization reaction was also discussed. The surface morphology of the obtained polymer film was characterized by X-ray diffraction and scanning electron microscopy.

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Electropolymerization of p-phenylenediamine (pPD) on Pt-electrode from a deoxygenated aqueous acid medium was carried out using cyclic voltammetry technique. The kinetic parameters were calculated by means of electrochemical data. The experimentally obtained kinetic equation was1.23 [acid] 1.24 [electrolyte] 0.94 from the value of the anodic current density. The apparent activation energy (E a ) is found to be 65.1 kJ mol À1. The obtained polymer films have been characterized by X-ray diffraction, elemental analysis, scanning electron microscopy, UV-vis, and IR spectroscopy. The conductivity of the polymer pellets is 6.3 Â 10 À7 S cmÀ1 . The mechanism of the electrochemical polymerization reaction has been discussed. TGA is used to confirm the proposed structure and determination of the number of water molecules in the polymeric chain unit. V C 2010Wiley Periodicals, Inc. J Appl Polym Sci 117: [943][944][945][946][947][948][949][950][951][952] 2010

The electrochemical and corrosion behaviour of Co 50 Ni 23 Ga 27Àx Al x (x ¼ 0 and 1.0 wt%) magnetic shape memory alloys (MSMAs) was studied in 0.5 M NaCl solutions using various electrochemical techniques.Results showed remarkable activation of the tested MSMA toward pitting corrosion upon alloying it with Al. XPS examination confirmed the activation influence of alloyed Al. It proved that the presence of Al in the alloy's matrix weakens its passivity, as manifested by a lower amount of gallium oxides and Cl and FE $ 100%). Our best catalyst also showed good stability and durability after 3000 cycles of cathodic polarization between the corrosion potential (E corr ) and À1.0 V vs. RHE, and 24 h of electrolysis at a high cathodic current density of 100 mA cm À2. Microstructure changes made by Al, together with findings obtained from SEM/EDX mapping and XPS studies, were used to interpret its activation influence towards the HER.