Impedance spectroscopy, coating

Impedance spectroscopy This technique is essentially the extension of polarization resistance measurements into low-conductivity environments, including those listed above. The technique can also be used to monitor atmospheric corrosion, corrosion under thin films of condensed liquid and the breakdown of protective paint coatings. Additionally, the method provides mechanistic data concerning the corrosion processes, which are taking place. 

A very recent example of the first case is presented by Vilaseca et al. [71] where an LTA coating on a micromachined sensor made the sensor much more selective to ethanol than methane. Moos et al. [72, 73] report H-ZSM5 NH3 sensor based on impedance spectroscopy using the zeolite as active sensing material. At elevated temperatures (>673 K) NH3 still adsorbs significantly in contrast to CO2, NO,... 

Initially, cycling in the coin cells, and later, in full prismatic cells with rated capacity of 7 Ah were used in our investigations. Also, advanced impedance spectroscopy methods were used to evaluate the electrochemical properties of coated materials. 

DOPC) monolayer-coated mercury electrodes in contact with different electrolytes, using electrochemical impedance spectroscopy and a multivariate analysis of impedance data. Rueda et al. [181] have analyzed impedance spectra of DOPC-coated mercury electrodes. 

What can we do for reversible (non polarizable) electrodes In this case we use the fact that different processes occur at different timescales. Instead of the relatively slow change of the voltage in cyclic voltametry, AC potentials with varying frequencies are applied and the current is detected. The method is called impedance spectroscopy. Using impedance spectroscopy, even semiconducting [100] or insulating materials can be analysed by coating them onto metallic electrodes. 

The conductivity of sintered pellets was obtained from two-probe impedance spectroscopy. Platinum electrodes were applied on both surfaces of pellets by coating platinum paste and then firing at 850°C for 0.5h. Measurements were made with an computer-interfaced impedance analyzer (GenRad 1689 Precision RLC Diglbridge) over a frequency range of 12-10 Hz in the temperature range of 500°C-800°C. Each sample was measured in air and H2 atmospheres, respectively. 

Electrochemical impedance spectroscopy (EIS) is a valuable method with which to study the barrier property and corrosion protection performance of polymer-coated metals it has been widely used in this field in recent years [11-15]. Many examples can be found in the literature, which illustrate the performance deterioration of different coatings on metals as well as pretreatment effects on the properties of... 

Cohen, S.M. Electrochemical impedance spectroscopy evaluation of various aluminum pretreatments painted with epoxy primer. J. Coatings Techn. 1996, 68 (859), 73. 

This book is intended to provide a background and training suitable for application of impedance spectroscopy to a broad range of applications, such as corrosion, biomedical devices, semiconductors and solid-state devices, sensors, batteries, fuel cells, electrochemical capacitors, dielectric measurements, coatings, elec-trochromic materials, analytical chemistry, and imaging. The emphasis is on generally applicable fundamentals rather than on detailed treatment of applications. The reader is referred to other sources for discussion of specific applications of impedance. ... 

The polyelectrolyte-tethered bilayers were investigated by means of time dependent surface plasmon spectroscopy, impedance spectroscopy, FRAP, as well as NR [27], The NR data given in Fig. 12 were first calculated based on a model that included the substrate and a box for the polyelectrolyte multilayer (A), and an additional box for the lipid bilayer (C). However, in order to fit the experimental NR curve, a top layer had to be added that was approximated by a uniform coating with average scattering length density b/V shown in the inset of Fig. 12. The thickness of... 

Kendig, M. et al. "The application of impedance spectroscopy to the evaluation of corrosion protection by inhibitors and polymer coatings", CORROSION 85. 1985, NACE, Houston, Texas, Paper 74. 

The nature and mobility of ions and solvent in zeolite cages will affect the ac-impedance of the material. This effect can be utilized for zeolite-based sensor concepts where a zeolite film is coated on interdigitated electrodes. For example, it was shown that the impedance of a film of proton-conducting H-ZSM-5 is influenced by the presence of ammonia (Figs. 15, 16).[126,127] The ammonia is protonated in the zeolite, thus producing much larger ammonium ions with different mobilities in the zeolite that can be detected by impedance spectroscopy. The detection of ammonia is of interest for automotive applications where the selective catalytic reduction of NOx by ammonia is envisioned. 

Piasecki, T., Nitsch, K., Pawlowski, L., and Jaworski, R. (2009) Impedance spectroscopy of suspension plasma sprayed hydroxyapatite coatings. Opt. AppL, 39 (4),... 

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