The Experts below are selected from a list of 1842 Experts worldwide ranked by ideXlab platform

Hidetaka Konno - One of the best experts on this subject based on the ideXlab platform.

  • Effects of pH and temperature on the deposition properties of stannate chemical conversion coatings formed by the Potentiostatic Technique on AZ91 D magnesium alloy
    Electrochimica Acta, 2008
    Co-Authors: Hassan H Elsentriecy, Kazuhisa Azumi, Hidetaka Konno
    Abstract:

    Abstract The effects of pH and temperature of a stannate bath on the quality of stannate chemical conversion coatings formed on AZ91 D magnesium alloy by using the Potentiostatic polarization Technique at E  = −1.1 V were investigated in order to improve uniformity and corrosion protection performance of the coating films. It was found that the uniformity and corrosion resistance of coating films deposited by Potentiostatic polarization were closely associated with pH and temperature of the coating bath. The pH and temperature to obtain the best coating film were investigated as a function of corrosion protection performance evaluated by curves of potentiodynamic anodic polarization conducted in borate buffer solution. Scanning electron microscope observation and electrochemical corrosion tests of the stannate-coated samples confirmed significant improvement in uniformity and corrosion resistivity of coating films deposited by the Potentiostatic Technique by modifying the pH and temperature of the coating bath. It was also found that uniformity and corrosion resistivity of the coating films deposited by the Potentiostatic Technique were considerably improved compared to those of coatings deposited by the simple immersion method at the best conditions of pH and temperature of the coating bath.

  • improvement in stannate chemical conversion coatings on az91 d magnesium alloy using the Potentiostatic Technique
    Electrochimica Acta, 2007
    Co-Authors: Hassan H Elsentriecy, Kazuhisa Azumi, Hidetaka Konno
    Abstract:

    The deposition of stannate chemical conversion coatings on AZ91 D magnesium alloy by using the Potentiostatic Technique was investigated to improve uniformity and corrosion protection performance of the coating film. It was found that anodic polarization during the stannate conversion process accelerated dissolution of magnesium ions and promoted deposition of the coating film. Optimal polarization potential was explored as a function of corrosion protection performance evaluated by potentiodynamic polarization curves in borate buffer solution. Scanning electron microscope observation and electrochemical corrosion tests of the stannate-coated samples confirmed significant improvement in uniformity and corrosion resistance of coatings deposited by the Potentiostatic Technique compared to those of coatings deposited by the simple immersion method.

Hassan H Elsentriecy - One of the best experts on this subject based on the ideXlab platform.

  • Effects of pH and temperature on the deposition properties of stannate chemical conversion coatings formed by the Potentiostatic Technique on AZ91 D magnesium alloy
    Electrochimica Acta, 2008
    Co-Authors: Hassan H Elsentriecy, Kazuhisa Azumi, Hidetaka Konno
    Abstract:

    Abstract The effects of pH and temperature of a stannate bath on the quality of stannate chemical conversion coatings formed on AZ91 D magnesium alloy by using the Potentiostatic polarization Technique at E  = −1.1 V were investigated in order to improve uniformity and corrosion protection performance of the coating films. It was found that the uniformity and corrosion resistance of coating films deposited by Potentiostatic polarization were closely associated with pH and temperature of the coating bath. The pH and temperature to obtain the best coating film were investigated as a function of corrosion protection performance evaluated by curves of potentiodynamic anodic polarization conducted in borate buffer solution. Scanning electron microscope observation and electrochemical corrosion tests of the stannate-coated samples confirmed significant improvement in uniformity and corrosion resistivity of coating films deposited by the Potentiostatic Technique by modifying the pH and temperature of the coating bath. It was also found that uniformity and corrosion resistivity of the coating films deposited by the Potentiostatic Technique were considerably improved compared to those of coatings deposited by the simple immersion method at the best conditions of pH and temperature of the coating bath.

  • improvement in stannate chemical conversion coatings on az91 d magnesium alloy using the Potentiostatic Technique
    Electrochimica Acta, 2007
    Co-Authors: Hassan H Elsentriecy, Kazuhisa Azumi, Hidetaka Konno
    Abstract:

    The deposition of stannate chemical conversion coatings on AZ91 D magnesium alloy by using the Potentiostatic Technique was investigated to improve uniformity and corrosion protection performance of the coating film. It was found that anodic polarization during the stannate conversion process accelerated dissolution of magnesium ions and promoted deposition of the coating film. Optimal polarization potential was explored as a function of corrosion protection performance evaluated by potentiodynamic polarization curves in borate buffer solution. Scanning electron microscope observation and electrochemical corrosion tests of the stannate-coated samples confirmed significant improvement in uniformity and corrosion resistance of coatings deposited by the Potentiostatic Technique compared to those of coatings deposited by the simple immersion method.

Alexander Milchev - One of the best experts on this subject based on the ideXlab platform.

  • Studies of electrochemical nucleation by means of standard and modified pulse Potentiostatic Techniques
    Electrochemistry Communications, 2000
    Co-Authors: Alexander Milchev, E. Michailova
    Abstract:

    This report compares experimental data for the overpotential dependence of the stationary nucleation rate Ist and of the induction time to obtained in two different ways: (i) by varying the potential En of the working electrode at a constant concentration of metal ions (standard pulse Potentiostatic Technique), and (ii) by varying the concentration of metal ions at a constant electrode potential En (modified pulse Potentiostatic Technique). It is shown that the latter experimental method allows us to fix the surface state of the working electrode and to create well-defined conditions for nucleus formation. Information is obtained on the rate-determining step of the nucleation process.

  • Electrochemical nucleation on active sites—what do we measure in reality? Part II
    Journal of Electroanalytical Chemistry, 1998
    Co-Authors: Alexander Milchev
    Abstract:

    This paper considers the process of electrochemical nucleation in the general case when active sites may appear and disappear from the electrode surface simultaneously with the nuclei of the new phase. In this case it is impossible to distinguish between the actual nucleation rate and the rate of appearance and disappearance of active sites, especially if the nucleation experiments are carried out by means of the standard pulse Potentiostatic Technique. To surmount this difficulty we propose a modified potential step method which allows one to fix the energetic state of the electrode surface.

Yaoming Xiao - One of the best experts on this subject based on the ideXlab platform.

  • dye sensitized solar cells with high performance polyaniline multi wall carbon nanotube counter electrodes electropolymerized by a pulse Potentiostatic Technique
    Journal of Power Sources, 2013
    Co-Authors: Yaoming Xiao, Jengyu Lin, Shengyen Tai, Gentian Yue, Tsungwu Lin
    Abstract:

    Abstract Strong scientific interests focus on the investigation of Pt-free counter electrodes (CEs) for their application in dye-sensitized solar cells (DSCs). Here we demonstrate the synthesis of a high-performance polyaniline/multi-wall carbon nanotube (PANI/MWCNT) nanocomposite CE via electrophoresis of MWCNTs onto a fluorinated tin oxide (FTO) substrate and then subjected to PANI electropolymerization by using the pulse Potentiostatic method. The resultant rough PANI thin film around the MWCNT is ∼45 nm in thickness. Cyclic voltammetry, electrochemical impedance spectroscopy, and Tafel polarization measurements reveal that PANI/MWCNT CE possesses an enhanced electrocatalytic activity for I 3 − reduction compared to PANI and MWCNT CEs due to its intrinsic superior electrocatalytic activity of the PANI material and high surface area of the MWCNTs. The DSC assembled with the pulsed PANI/MWCNT CE exhibits the superior photovoltaic conversion efficiency of 6.24% (compared to 5.18% for DSCs with PANI CE or 6.05% for DSCs with Pt CE) under full sunlight illumination (100 mW cm −2 , AM1.5 G). Therefore, the high-performance PANI/MWCNT can be considered as a cost-effective CE alternative for DSCs.

E. Michailova - One of the best experts on this subject based on the ideXlab platform.