0000000000807615
AUTHOR
Hisasi Takenouti
showing 3 related works from this author
Electrochemical impedance spectroscopy for studying passive layers on steel rebars immersed in alkaline solutions simulating concrete pores
2007
Present paper deals with the use of the electrochemical impedance spectroscopy to identify different processes in the passive layer growth over steel rebar surface immersed in an alkaline media simulating the concrete pore solution. Two cases have been considered: a passive layer spontaneously grown in a high alkaline media and a passive layer assisted by the application of an anodic potential in the same media. The application of electric equivalent circuits allows distinguishing between the different mechanisms occurring in this passive layer when grows in different conditions. An electric equivalent circuit with two RC loops connected in parallel is often used for fitting the EIS diagram…
An electrochemical quartz crystal microbalance study of lithium insertion into thin films of tungsten trioxide I. Modeling of the ionic insertion mec…
1995
A theoretical description of the mechanism of lithium insertion into amorphous thin films of tungsten trioxide (a-WO3) prepared by thermal vacuum evaporation of WO3 powder is presented. The model developed is based on the experimental results obtained by chronoamperometry and ac impedance spectroscopy associated with electrochemical quartz crystal microbalance (EQCM). The electrode mass change and the current flowing through the electrochemical cell during cathodic polarization are simulta neously recorded. As expected, it can be observed that the insertion process is associated with a gain of mass of the inserted electrode at long times (t > 1 s). On the other hand at short times (t < 1 s)…
Laser depassivation of a channel flow double-electrode: A new technique in repassivation studies
1993
Abstract A powerful tool for distinguishing between the different electrochemical steps involved during a depassivation-repassivation sequence was developed by combining the pulsed laser depassivation technique with an hydrodynamic electrochemical method: the channel flow double-electrode (CFDE). This experiment consisted of transporting the chemical species (Fe 2+ ) released by a depassivated iron electrode to a collecting electrode where these species were oxidized. A qualitative idea of the relative contribution of the anodic dissolution to the repassivation behavior was obtained. For a passive iron in acidic solution it was found that about 15% of the total charge is related to anodic d…