scholarly journals In situ drug release measuring in α-TCP cement by electrochemical impedance spectroscopy

2021 ◽  
Vol 32 (4) ◽  
Author(s):  
Júnio Augusto Rodrigues Pasqual ◽  
Lucas C. Freisleben ◽  
Júlio Cesar Colpo ◽  
Jose Ramón Jurado Egea ◽  
Luis Alberto Loureiro dos Santos ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Drug Application ◽  
Chemical Mechanism ◽  
Before And After ◽  
Good Technique ◽  
The Right ◽  
Non Destructive

AbstractThe use of drug delivery systems is a good technique to leave the right quantity of medicine in the patient’s body in a suitable dose, because the drug application is delivered directly to the affected region. The current techniques such as HPLC and UV–Vis for the drug delivery calculation has some disadvantages, as the accuracy and the loss of the sample after characterization. With the aim of reducing the amount of material used during the characterization and have a non-destructive test with instantaneous results, the present paper shows the possibility of using electrochemical impedance spectroscopy (EIS) to have a drug delivery measurement during the release phenomena for a calcium phosphate cement (CFC) delivery system with gentamicin sulfate (GS) and lidocaine hydrochloride (LH), at a ratio of 1% and 2%, respectively. The equivalent circuit and the chemical mechanism involved during the measurements have been proposed as a tool to determine the drug delivery profile. The method has been compared with the UV–Vis technique. XRD was realized to verify conditions, before and after release. It was possible to verify the potential for using EIS as an instant technique to quantify drug delivery.

scholarly journals Degradation Phenomena of Bismuth-Modified Felt Electrodes in VRFB Studied by Electrochemical Impedance Spectroscopy

Batteries ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 16 ◽  
Author(s):  
Jonathan Schneider ◽  
Eduard Bulczak ◽  
Gumaa El-Nagar ◽  
Marcus Gebhard ◽  
Paul Kubella ◽  
...  
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Modified Electrodes ◽  
Impregnation Method ◽  
Carbon Felt ◽  
Half Cell ◽  
Negative Side ◽  
Prolonged Contact ◽  
Before And After

The performance of all-V redox flow batteries (VRFB) will decrease when they are exposed to dynamic electrochemical cycling, but also when they are in prolonged contact with the acidic electrolyte. These phenomena are especially severe at the negative side, where the parasitic hydrogen evolution reaction (HER) will be increasingly favored over the reduction of V(III) with ongoing degradation of the carbon felt electrode. Bismuth, either added to the electrolyte or deposited onto the felt, has been reported to suppress the HER and therefore to enhance the kinetics of the V(II)/V(III) redox reaction. This study is the first to investigate degradation effects on bismuth-modified electrodes in the negative half-cell of a VRFB. By means of a simple impregnation method, a commercially available carbon felt was decorated with Bi 2 O 3 , which is supposedly present as Bi(0) under the working conditions at the negative side. Modified and unmodified felts were characterized electrochemically using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) in a three-electrode setup. Surface morphology of the electrodes and composition of the negative half-cell electrolyte were probed using scanning electron microscopy (SEM) and X-ray fluorescence spectroscopy (TXRF), respectively. This was done before and after the electrodes were subjected to 50 charge-discharge cycles in a battery test bench. Our results suggest that not only the bismuth catalyst is dissolved from the electrode during battery operation, but also that the presence of bismuth in the system has a strong accelerating effect on electrode degradation.

scholarly journals Electrochemical Impedance Spectroscopy for the Measurement of the Corrosion Rate of Magnesium Alloys: Brief Review and Challenges

Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 775 ◽  
Author(s):  
Sebastián Feliu
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Corrosion Rate ◽  
Electrochemical Impedance ◽  
State Of The Art ◽  
Point Of View ◽  
Reliable Determination ◽  
Corrosion Rates ◽  
Non Destructive

From a technological point of view, measurement of the corrosion rate of magnesium (Mg) and its alloys is critical for lifetime predictions of Mg-based structures and for comparative assessments of their corrosion protection ability. Whilst weight loss, hydrogen evolution, and polarization curves methods are frequently used for measuring the corrosion rate, the determination of values by electrochemical impedance spectroscopy (EIS) is relatively scarce and has only been realized recently. This technique seems to be the most suitable for monitoring corrosion rate values due to its “non-destructive” character, its reproducibility, and its reliable determination of small corrosion rates, much lower than those measured by other techniques. This review aims to picture the state-of-the-art technique of using EIS for measuring the corrosion rate of Mg. This paper starts by introducing some fundamental aspects of the most widely used methods for monitoring the corrosion rate of Mg/Mg alloy and continues by briefly explaining some of the fundamental concepts surrounding EIS, which are essential for the user to be able to understand how to interpret the EIS spectra. Lastly, these concepts are applied, and different approaches that have been proposed to obtain quantitative values of corrosion rate since the 1990s are discussed.

scholarly journals Reducing the resistance for the use of electrochemical impedance spectroscopy analysis in materials chemistry

RSC Advances ◽  
2021 ◽  
Vol 11 (45) ◽  
pp. 27925-27936
Author(s):  
Nadia O. Laschuk ◽  
E. Bradley Easton ◽  
Olena V. Zenkina
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Intermediate Level ◽  
Materials Characterization ◽  
Electrochemical Technique ◽  
Materials Chemistry ◽  
Spectroscopy Analysis ◽  
Non Destructive ◽  
Impedance Spectroscopy Analysis

This manuscript highlights a beginner-to-intermediate level scope of electrochemical impedance spectroscopy (EIS), which is an indispensable, non-destructive electrochemical technique that can be applied for materials characterization.

Study on the Surface Fractures of Nanoparticle Silicon Anode for Lithium-Ion Batteries

2015 ◽  
Vol 1092-1093 ◽  
pp. 216-219
Author(s):  
Pan Li Ren ◽  
Xu Ma ◽  
Ling Long Kong
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Lithium Ion Batteries ◽  
Electrochemical Impedance ◽  
Specific Capacity ◽  
Lithium Ion ◽  
Silicon Anode ◽  
Cyclic Voltammograms ◽  
Capacity Curves ◽  
Before And After

In this paper the fractures appeared in the surface of nanoparticle silicon anode for lithium-ion batteries was explored. The changes of nanoparticle silicon anode before and after cycling were charactered using SEM, XRD,Cyclic voltammograms (CV) and electrochemical impedance spectroscopy (EIS). The result indicates that the electrode cracking occured in the cycling process , the CV, EIS and discharge specific capacity curves proved the fractures could lead to the degradation of the electrochemical performance.

Surface and Structure of Porous Silicon Layers

2007 ◽  
Vol 31 ◽  
pp. 170-172 ◽  
Author(s):  
Jing Mei Lu ◽  
Xuan Cheng
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Porous Silicon ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Surface Parameters ◽  
Electrolyte Interface ◽  
Before And After

The porous silicon (PS) layers were fabricated on n(100) and n(111) silicon by applying the constant and repeated currents in different HF solutions. The electrochemical impedance spectroscopy (EIS) was used to in-situ characterize the Si/electrolyte interface before and after the PS formations. The surface and structure of PS layers were examined in terms of electrochemical/surface parameters.

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