Impedance spectroscopy method

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. 

In this part we will describe recent achievements in the development of biosensors based on DNA/RNA aptamers. These biosensors are usually prepared by immobilization of aptamer onto a solid support by various methods using chemisorption (aptamer is modified by thiol group) or by avidin-biotin technology (aptamer is modified by biotin) or by covalent attachment of amino group-labeled aptamer to a surface of self-assembly monolayer of 11-mercaptoundecanoic acid (11-MUA). Apart from the method of aptamer immobilization, the biosensors differ in the signal generation. To date, most extensively studied were the biosensors based on optical methods (fluorescence, SPR) and acoustic sensors based mostly on thickness shear mode (TSM) method. However, recently several investigators reported electrochemical sensors based on enzyme-labeled aptamers, electrochemical indicators and impedance spectroscopy methods of detection. 

The impedance spectroscopy method in electrochemistry has been greatly developed in recent years by the availability of state-of-the-art frequency-response analyzers capable of measuring ac impedance over wide frequency... 

Fig. 6.13 Applied potential and resultant external current relative to the electrochemical impedance spectroscopy method...

Fie. 6.19 Electrochemical impedance spectroscopy method, Nyquist data-presentation format... 

Because of the resistance to ion flow at the electrode-electrolyte interface, normal measurement of total ionic conductivity is not possible in polymer electrolytes. In order to overcome this problem the conductivity measurements are carried out by the ac impedance spectroscopy method, which minimizes the effects of cell polarization. The measurements are often made with the electrolyte sandwiched between a pair of electrochemically inert electrodes made of platinum or stainless steel. The detailed methodology of impedance spectroscopy is reviewed thoroughly elsewhere [45-47]. 

Abstract The impedance spectroscopy method was used to study conductivity of a... 

A fragment of a tube with the wall 0.5 mm thick was cut for conductivity measurements. Large opposite surfaces had silver electrodes, which were fused at 700 °C for nearly 18 hours. Measurements were made using the two-probe impedance spectroscopy method on a lm6 instrument (Zahner-Elektrik) in air at frequencies from 10 to 8-10 Hz over the temperature interval of 220 to 700 °C with steps of 20-50 degrees. 

One can envision three types of perturbation an infinitesimally narrow light pulse (a Dirac or S-functional), a rectangular pulse (characteristic of chopped or interrupted irradiation), or periodic (usually sinusoidal) excitation. All three types of excitation and the corresponding responses have been treated on a common platform using the Laplace transform approach and transfer functions [170]. These perturbations refer to the temporal behavior adopted for the excitation light. However, classical AC impedance spectroscopy methods employing periodic potential excitation can be combined with steady state irradiation (the so-called PEIS experiment). In the extreme case, both the light intensity and potential can be modulated (at different frequencies) and the (nonlinear) response can be measured at sum and difference frequencies. The response parameters measured in all these cases are many but include... 

It is worth pointing out that, although DC measurements have the inherent advantages such as simple instruments and straightforward interpretation, the dynamics of transport processes are not readily accessible. Therefore, AC impedance spectroscopy methods have also been used. For example, a frequency range of 0.2-1000 kHz, a capacitance bridge is coupled to an external oscillator. Sometimes electrical connection to the aqueous solutions is made via two sheet Pt electrodes (1 cm ) coated with Pt black, or Ag/AgCl electrodes. Impedance spectroscopy, also referred to as EIS, is a well-established... 

E. Ivers-Tiffee, A. Weber, H. Schichlein, Electrochemical impedance spectroscopy (methods in electrocatalysis for fuel cells), in Handbook of Fuel Cells Fundamentals, Technology, Applications, ed. by W. Vielstich, A. Lamm, H. Gasteiger, vol. 2 (Wiley, Chichester, 2003), pp. 220-235... 

K. Bundy, M. Karlsson, G. Lindbergh, and A. Lundqvist [1998] An Electrochemical Impedance Spectroscopy Method for Prediction of the State of Charge of a Nickel-Metal Hydride Battery at Open Circuit and During Discharge, J. Power Sources 72, 118-125. 

Electrochemical Impedance Spectroscopy Method of Determining Lubricant Properties... 

Impedance is an essential characterization of the current intensity response of the corrosion system to the sinusoidal perturbation of the potential applied to the metal. The results of impedance measurements made in a suitably wide range of frequencies provide valuable information about the system and electrochemical corrosion occurring therein. The majority of electrochemical as well as physical processes can be interpreted within the impedance spectroscopy method as elements of electrical circuits with appropriate time constants. Thus, to interpret the results of electrochemical impedance measurements surrogate models of electrical circuits, known as Randles models, can be used. 

Electrochemical corrosion characteristics of nickel were carried out by potentiodynamic polarization and impedance spectroscopy methods. Corrosion tests of nickel produced by electrocrystallization were ap>plied to its micrometric (Nim) and nanometric (Ni ) crystalline structures and for NiP amorphous alloy of nickel with phosphorus at content of 10.7% by weight (Eftekhari, 2008), (Kowalewska Trzaska, 2006). 

The potential excitation and its current response are schematically shown in Figure 35 as sinusoidal excitations. The electrochemical impedance spectroscopy method is conducted according to the ASTM G-106 standard practice, in which a range of smaU-amphtude sinusoidal potential perturbation is applied to the electrode/sohition interface at discrete frequencies. These frequencies cause an out of phase current response with respect to the applied sinusoidal potential waveform. 

Journal of Polymers and the Environment 8, No.4, Oct. 2000, p. 167-74 SENSITIVE ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY METHOD FOR DETECTION OF POLYIMIDE DEGRADATION BY... 

This book incorporates the results of the last two decades of research on the theories and applications of impedance spectroscopy, including more detailed reviews of the impedance methods applications in industrial colloids, biomedical sensors and devices, and supercapacitive polymeric films. The book is organized so each chapter stands on its own. The book should assist readers to quickly grasp how to apply their new knowledge of impedance spectroscopy methods to their own research problems through the use of features such as ... 

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