scholarly journals Charge Transfer Resistance and Adsorption performance of a New Pyrrole Derivative on Mild steel in Acidic media: Antibacterial studies

2021 ◽  
Vol 37 (4) ◽  
pp. 779-790
Author(s):  
G. Pandimuthu ◽  
P. Muthukrishnan ◽  
S. Rameshkumar ◽  
K. Paramasivaganesh ◽  
A. Sankar

In the present work, Pyrrole derivatives containing oxygen, nitrogenand aromatic rings namely,N-(1H-Pyrrol-2-ylmethylidene)-2,3-dihydro-1,4-benzodioxin-6-amine (BPS) was synthesized and its anticorrosion potential was studied applying the gravimetric, polarization and AC impedance methods on the mild steel (MS) corrosion in corrodent (0.5M H2SO4 and 1 M HCl). It is observed that in the acidic environments, the inhibition efficiency (IE) of the BPS raised with the enhance in the concentration and it resulted in greater inhibition efficiency in1 M HCl solution than in 0.5M H2SO4 solution. The inhibition efficiency assessed by Electrochemical Impedance Spectroscopy reaches about 81.6% in 0.5 M H2SO4 and 84.2% in 1.0 M HCl solutions at 600 ppm of BPS.The studied BPS being mixed type inhibitor was shown by the Tafel polarization curves. And it was noticed that over the MS surface, the adsorption of the BPS obeyed Langmuirisotherm. In order to ascertain the inhibitor mechanism, the potential of zero charge (PZC) was measured. Electrochemical Impedance spectroscopy was applied to assess the influence of temperature on corrosion inhibition.The surface morphology of MS surface was analyzed using SEM and AFM techniques. The anti-bacterial activity for the BPS was studied as a divergent analysis.

2010 ◽  
Vol 64 (1) ◽  
Author(s):  
Niketan Patel ◽  
Smita Jauhari ◽  
Girishkumar Mehta

AbstractInhibition effect of imidazole derivative 1,7′-dimethyl-2′-propyl-1H,3′H-2,5′-bibenzo[d]imidazole (DPBI) against mild steel corrosion in 1 M HCl solutions was evaluated using the conventional mass loss method, potentiodynamic polarization, linear polarization, and electrochemical impedance spectroscopy. The mass loss results showed that DPBI is an excellent corrosion inhibitor; electrochemical polarizations data revealed the mixed mode of inhibition; and the results of electrochemical impedance spectroscopy showed that the change in the impedance parameters, charge transfer resistance, and double layer capacitance with the change in the concentration of the inhibitor is due to the adsorption of the molecule leading to the formation of a protective layer on the surface of mild steel. The inhibition action of this compound was assumed to occur via adsorption on the steel surface through the active centers of the molecule.


2021 ◽  
Vol 33 (12) ◽  
pp. 2953-2964
Author(s):  
Vikas Kalia ◽  
Pradeep Kumar ◽  
Suresh Kumar ◽  
Hariom Dahiya

The corrosion inhibition consequence of 5-(4-aminophenyl)-1,3,4-oxadiazole-2-thiol (APOT) and 5-(4-methylphenyl)-1,3,4-oxadiazole-2-thiol (MPOT) were accomplished by employing weight loss measurement, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization measurement and scanning electron microscope (SEM). An impact of immersion time 12.0 h and different temperatures (298, 308 and 318 K) with solution of 1.0 M HCl, which include various concentration of inhibitor at the corrosion of mild steel were designed. Weight loss measurement showed that with enhancing the concentration of these studied inhibitors the percentage inhibition efficiency (IE%) enhances, but corrosion rate (CR) diminishes while reverse condition in case of temperatures change. The electrochemical impedance spectroscopy examine pointed out that the charge transfer resistance (Rct) values enhances and consequently the double layer capacitance (Cdl) values diminishes with rising each inhibitor concentration in 1.0 M HCl and also there is a formation of adsorption coating at the metal surface. Polarization measurement showed that both APOT and MPOT perform as mixed type corrosion inhibitors. Furthermore, the adsorption behaviour on surface of mild steel for each studied inhibitor results the Langmuir adsorption isotherm. Surface conduct of mild steel also designed through the SEM and energy dispersive X-ray (EDX) analysis and concludes that there is evolution of inhibitive film of APOT and MPOT on the surface of mild steel.


Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 788
Author(s):  
Hien T. Ngoc Le ◽  
Sungbo Cho

Aggregation of amyloid-β (aβ) peptides into toxic oligomers, fibrils, and plaques is central in the molecular pathogenesis of Alzheimer’s disease (AD) and is the primary focus of AD diagnostics. Disaggregation or elimination of toxic aβ aggregates in patients is important for delaying the progression of neurodegenerative disorders in AD. Recently, 4-(2-hydroxyethyl)-1-piperazinepropanesulfonic acid (EPPS) was introduced as a chemical agent that binds with toxic aβ aggregates and transforms them into monomers to reduce the negative effects of aβ aggregates in the brain. However, the mechanism of aβ disaggregation by EPPS has not yet been completely clarified. In this study, an electrochemical impedimetric immunosensor for aβ diagnostics was developed by immobilizing a specific anti-amyloid-β (aβ) antibody onto a self-assembled monolayer functionalized with a new interdigitated chain-shaped electrode (anti-aβ/SAM/ICE). To investigate the ability of EPPS in recognizing AD by extricating aβ aggregation, commercially available aβ aggregates (aβagg) were used. Electrochemical impedance spectroscopy was used to probe the changes in charge transfer resistance (Rct) of the immunosensor after the specific binding of biosensor with aβagg. The subsequent incubation of the aβagg complex with a specific concentration of EPPS at different time intervals divulged AD progression. The decline in the Rct of the immunosensor started at 10 min of EPPS incubation and continued to decrease gradually from 20 min, indicating that the accumulation of aβagg on the surface of the anti-aβ/SAM/ICE sensor has been extricated. Here, the kinetic disaggregation rate k value of aβagg was found to be 0.038. This innovative study using electrochemical measurement to investigate the mechanism of aβagg disaggregation by EPPS could provide a new perspective in monitoring the disaggregation periods of aβagg from oligomeric to monomeric form, and then support for the prediction and handling AD symptoms at different stages after treatment by a drug, EPPS.


2009 ◽  
Vol 2009 ◽  
pp. 1-15 ◽  
Author(s):  
Minna Toivola ◽  
Janne Halme ◽  
Lauri Peltokorpi ◽  
Peter Lund

Effects of aging and cyclically varying temperature on the electrical parameters of dye solar cells were analyzed with electrochemical impedance spectroscopy. Photoelectrode total resistance increased as a function of time due to increasing electron transport resistance in theTiO2film. On the other hand, photoelectrode recombination resistance was generally larger, electron lifetimes in theTiO2were film longer, and charge transfer resistance on the counter electrode was smaller after the temperature treatments than before them. These effects correlated with the slower deterioration rate of the temperature-treated cells, in comparison to the reference cells.


Chemosensors ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 27
Author(s):  
Georg Christoph Brunauer ◽  
Oliver Spadiut ◽  
Alfred Gruber ◽  
Christoph Slouka

Electrochemical impedance spectroscopy is a powerful tool in life science for cell and pathogen detection, as well as for cell counting. The measurement principles and techniques using impedance spectroscopy are highly diverse. Differences can be found in used frequency range (β or α regime), analyzed quantities, like charge transfer resistance, dielectric permittivity of double layer capacitance and in off- or online usage. In recent contributions, applications of low-frequency impedance spectroscopy in the α regime were tested for determination of cell counts and metabolic burden in Escherichia coli and Saccharomyces cerevisiae. The established easy to use methods showed reasonable potential in the lab scale, especially for S. cerevisiae. However, until now, measurements for cell counts in food science are generally based on Thoma cell counting chambers. These microscopic cell counting methods decelerate an easy and quick prediction of yeast viability, as they are labor intensive and result in a time delayed response signal. In this contribution we tested our developed method using low frequency impedance spectroscopy locally at an industrial brewery propagation site and compared results to classic cell counting procedures.


Energies ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 4507 ◽  
Author(s):  
Yusuke Abe ◽  
Natsuki Hori ◽  
Seiji Kumagai

Lithium-ion batteries (LIBs) using a LiFePO4 cathode and graphite anode were assembled in coin cell form and subjected to 1000 charge-discharge cycles at 1, 2, and 5 C at 25 °C. The performance degradation of the LIB cells under different C-rates was analyzed by electrochemical impedance spectroscopy (EIS) and scanning electron microscopy. The most severe degradation occurred at 2 C while degradation was mitigated at the highest C-rate of 5 C. EIS data of the equivalent circuit model provided information on the changes in the internal resistance. The charge-transfer resistance within all the cells increased after the cycle test, with the cell cycled at 2 C presenting the greatest increment in the charge-transfer resistance. Agglomerates were observed on the graphite anodes of the cells cycled at 2 and 5 C; these were more abundantly produced in the former cell. The lower degradation of the cell cycled at 5 C was attributed to the lowered capacity utilization of the anode. The larger cell voltage drop caused by the increased C-rate reduced the electrode potential variation allocated to the net electrochemical reactions, contributing to the charge-discharge specific capacity of the cells.


Soft Matter ◽  
2014 ◽  
Vol 10 (34) ◽  
pp. 6467-6476 ◽  
Author(s):  
Choonghyun Sung ◽  
Katelin Hearn ◽  
Jodie Lutkenhaus

Layer-by-layer assemblies exhibit increased conductivity and decreased charge transfer resistance upon heating through the thermal transition.


Author(s):  
Moussa Ouakki ◽  
Mouhsine Galai ◽  
Mohammed Cherkaoui ◽  
Mohamed Ebn Touhami ◽  
E. H. Rifi ◽  
...  

The corrosion inhibition of mild steel in hydrochloric, sulfuric, and phosphoric acids solutions containing a mineral compound-based phosphate (apatite) was evaluated by potentiodynamic polarization and electrochemical impedance spectroscopy. Potentio-dynamic polarization measurements reveal that the inhibition efficiency increased with the concentration of the apatite, which appears to be a cathodic type inhibitor in the three mediums. Electrochemical impedance spectroscopy confirms this result; indeed, the transfer resistance increases with apatite concentration. The authors note that the double layer capacitance decreases simultaneously suggesting the formation of an adsorbed layer on the mild steel surface. The inhibition mechanism has been elucidated by a thermodynamic study, which showed that the film was formed by physi-sorption. The adsorption model obeys to the Langmuir adsorption isotherm. The parameters of activation energy were evaluated and discussed.


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