scholarly journals Role of Modern Localised Electrochemical Techniques to Evaluate the Corrosion on Heterogeneous Surfaces

10.5772/57204 ◽  
2014 ◽  
Author(s):  
Rafael Leiva-García ◽  
Rita Sánchez-Tovar ◽  
Clara Escrivà-Cerdán ◽  
José García-Antón
Keyword(s):  
Electrochemical Techniques ◽  
Heterogeneous Surfaces

scholarly journals On the Role of the Cathode for the Electro-oxidation of Perfluorooctanoic Acid

2020 ◽  
Author(s):  
Alicia Garcia-Costa ◽  
André Savall ◽  
Juan A. Zazo ◽  
Jose A. Casas ◽  
Karine Groenen Serrano
Keyword(s):  
Electrochemical Techniques ◽  
High Strength ◽  
Perfluorooctanoic Acid ◽  
Reduction Reaction ◽  
Adsorbed Hydrogen ◽  
Boron Doped Diamond ◽  
Bdd Anode ◽  
Boron Doped ◽  
Initial Ph

Perfluorooctanoic acid (PFOA), C7F15COOH, has been widely employed over the past fifty years, causing an environmental problem due to its dispersion and low biodegradability. Furthermore, the high stability of this molecule, conferred by the high strength of the C-F bond makes it very difficult to remove. In this work, electrochemical techniques are applied for PFOA degradation in view to study the influence of the cathode on defluorination. For this purpose, boron doped diamond (BDD), Pt, Zr and stainless steel have been tested as cathodes working with BDD anode at low electrolyte concentration (3.5 mM) to degrade PFOA at 100 mg/L. Among these cathodic materials, Pt improves the defluorination reaction. The electro-degradation of a PFOA molecule starts by a direct exchange of one electron at the anode and then follows a complex mechanism involving reaction with hydroxyl radicals and adsorbed hydrogen on the cathode. It is assumed that Pt acts as an electrocatalyst, enhancing PFOA defluorination by the reduction reaction of perfluorinated carbonyl intermediates on the cathode. The defluorinated intermediates are then more easily oxidized by HO• radicals. Hence, high mineralization (xTOC: 76.1%) and defluorination degrees (xF-: 58.6%) were reached with Pt working at current density j = 7.9 mA/cm2. This BDD-Pt system reaches a higher efficiency in terms of defluorination for a given electrical charge than previous works reported in literature. Influence of the electrolyte composition and initial pH are also explored.

scholarly journals On the Role of the Cathode for the Electro-Oxidation of Perfluorooctanoic Acid

Catalysts ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 902
Author(s):  
Alicia L. Garcia-Costa ◽  
Andre Savall ◽  
Juan A. Zazo ◽  
Jose A. Casas ◽  
Karine Groenen Serrano
Keyword(s):  
Electrochemical Techniques ◽  
High Strength ◽  
Perfluorooctanoic Acid ◽  
Reduction Reaction ◽  
Adsorbed Hydrogen ◽  
Boron Doped Diamond ◽  
Bdd Anode ◽  
Boron Doped ◽  
Initial Ph

Perfluorooctanoic acid (PFOA), C7F15COOH, has been widely employed over the past fifty years, causing an environmental problem because of its dispersion and low biodegradability. Furthermore, the high stability of this molecule, conferred by the high strength of the C-F bond makes it very difficult to remove. In this work, electrochemical techniques are applied for PFOA degradation in order to study the influence of the cathode on defluorination. For this purpose, boron-doped diamond (BDD), Pt, Zr, and stainless steel have been tested as cathodes working with BDD anode at low electrolyte concentration (3.5 mM) to degrade PFOA at 100 mg/L. Among these cathodic materials, Pt improves the defluorination reaction. The electro-degradation of a PFOA molecule starts by a direct exchange of one electron at the anode and then follows a complex mechanism involving reaction with hydroxyl radicals and adsorbed hydrogen on the cathode. It is assumed that Pt acts as an electrocatalyst, enhancing PFOA defluorination by the reduction reaction of perfluorinated carbonyl intermediates on the cathode. The defluorinated intermediates are then more easily oxidized by HO• radicals. Hence, high mineralization (xTOC: 76.1%) and defluorination degrees (xF−: 58.6%) were reached with Pt working at current density j = 7.9 mA/cm2. This BDD-Pt system reaches a higher efficiency in terms of defluorination for a given electrical charge than previous works reported in literature. Influence of the electrolyte composition and initial pH are also explored.

The role of chromogranins in the secretory pathway

2013 ◽  
Vol 4 (6) ◽  
pp. 605-609 ◽  
Author(s):  
Judith Estevez-Herrera ◽  
Marta R. Pardo ◽  
Natalia Dominguez ◽  
Daniel Pereda ◽  
Jose D. Machado ◽  
...  
Keyword(s):  
Chromaffin Cells ◽  
Secretory Pathway ◽  
Electrochemical Techniques ◽  
Mouse Strains ◽  
Secretory Vesicles ◽  
Functional Roles ◽  
Large Dense Core Vesicles ◽  
Soluble Species ◽  
Adrenal Chromaffin

AbstractChromogranins (Cgs) are acidic proteins implicated in several physiological processes, including the biogenesis and sorting of secretory vesicles, the generation of bioactive peptides, and the accumulation of soluble species inside large dense core vesicles (LDCV). Indeed, Cgs are the main protein component of the vesicular matrix in LDCV, and they are involved in the concentration of soluble species like neurotransmitters and calcium. Experiments using electrochemical techniques such amperometry, patch amperometry, and intracellular electrochemistry have clarified the functional roles of Cgs in the accumulation and release of catecholamines. We have focused this review at a single event of exocytosis of chromaffin cells from three mouse strains lacking Cgs. Accordingly, in this brief review, we will focus on the role of Cgs in maintaining the intravesicular environment of secretory vesicles and in exocytosis, bringing together the most recent findings from studies on adrenal chromaffin cells.

Electrochemical Kinetics Study of Electroless Copper Plating for Electronics Application

2004 ◽  
Vol 449-452 ◽  
pp. 393-396
Author(s):  
Dae Geun Kim ◽  
Jin Soo Bae ◽  
Jae Ho Lee ◽  
Yang Do Kim ◽  
Yoo Min Ahn
Keyword(s):  
Electrochemical Techniques ◽  
Deposition Process ◽  
Electrolyte Composition ◽  
Electrochemical Kinetics ◽  
Kinetics Study ◽  
Mixed Potential ◽  
Copper Plating ◽  
Electroless Copper Plating ◽  
Electroless Copper

Electroless copper plating was investigated for the electronics applications, such as a metallization for ULSI and MEMS etc. The role of electrolyte composition on the kinetics and mechanism of the electroless copper deposition process was described. Electrochemical techniques were employed for the investigations. The mixed potential and current were determined and then those were compared with experimental deposition rate. The kinetics is strongly influenced by the pretreatment and additive concentrations.

Leveraging electrochemistry to uncover the role of nitrogen in the biological reactivity of nitrogen-doped graphene

2019 ◽  
Vol 6 (12) ◽  
pp. 3525-3538 ◽  
Author(s):  
Yan Wang ◽  
Nathalia Aquino de Carvalho ◽  
Susheng Tan ◽  
Leanne M. Gilbertson
Keyword(s):  
Oxidative Stress ◽  
Active Site ◽  
Electrochemical Techniques ◽  
Nitrogen Doped ◽  
Nitrogen Doped Graphene ◽  
Doped Graphene

Electrochemical techniques are leveraged to probe the influence of N-bonding types on the bioactivity of nitrogen-doped graphene, with graphitic-N identified to be the active site for oxidative stress-related bioactivity.

Interfaces of Ionically Conducting Materials: Electrochemical Properties

1994 ◽  
Vol 357 ◽  
Author(s):  
Joachim Maier
Keyword(s):  
Atomic Force Microscopy ◽  
Solid State ◽  
Electrochemical Techniques ◽  
Two Dimensional ◽  
Ionic Conductors ◽  
Force Microscopy ◽  
Atomic Force ◽  
Solid State Ionics ◽  
Conducting Materials

AbstractThis contribution summarizes former results and presents recent findings concerning interfacial properties in solid state ionics but also stresses the model role of ionic conductors for typical ceramic problems. Moreover, recently developed and improved electrochemical techniques allowing spatial resolution are discussed, viz. a two-dimensional impedance spectroscopy as well as a combination of microelectrochemistry and atomic force microscopy.

scholarly journals Beneficial Effects of Vanadium Additions on the Corrosion of Ti6AlxV Alloys in Chloride Solutions

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 264 ◽  
Author(s):  
El-Sayed M. Sherif ◽  
Hany S. Abdo ◽  
Nabeel H. Alharthi
Keyword(s):  
Electron Microscopy ◽  
Immersion Time ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Test Medium ◽  
X Ray ◽  
Beneficial Effects ◽  
Cyclic Potentiodynamic Polarization ◽  
Scanning Electron

The beneficial effects of V addition on the corrosion of a newly manufactured Ti6AlxV (x = 2 wt %, 4 wt %, 6 wt %, and 8 wt %) alloys after various exposure periods in 3.5% NaCl solutions were reported. The Ti6AlxV were produced from their raw powders using mechanical alloying. Several electrochemical techniques such as electrochemical impedance spectroscopy, cyclic potentiodynamic polarization, and potentiodynamic current versus time at 300 mV experiments were conducted. The surface morphology and the elemental analysis were performed using scanning electron microscopy and energy dispersive X-ray analyses. All results were consistent with each other revealing that the increase of V content increases the resistance of the alloys against corrosion. The increase of corrosion resistance was achieved by the role of V in decreasing the rate of corrosion as a result of the formation of oxide films on the surface of the alloys. This effect was found to increase with prolonging the immersion time of the Ti6AlxV alloys in the test medium from 1 h to 24 h and further to 48 h.

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