A Voltammetric Investigation of AC Corrosion Phenomena at an Aluminum Electrode in Hydrochloric Acid

CORROSION ◽  
1984 ◽  
Vol 40 (12) ◽  
pp. 644-649 ◽  
Author(s):  
W. Michael Moore ◽  
Chia-Tien Chen ◽  
George A. Shirn
Keyword(s):  
Cyclic Voltammetry ◽  
High Speed ◽  
Solution Temperature ◽  
Aluminum Electrode ◽  
Half Cycle ◽  
Potential Sweep ◽  
Cathodic Potential ◽  
Square Wave ◽  
Onset Potential ◽  
Hcl Concentration

Abstract The electrochemical behavior of Al in HCl has been studied by cyclic voltammetry, square-wave chronoamperometry, and square-wave chronopotentiometry. High speed cyclic voltammetry was studied thoroughly, and the effects of temperature, HCl concentration, potential sweep rate, and cathodic potential limit were examined. Relevant parameters that can be determined from the cyclic voltammetric i-V curve include the breakdown and protection potentials for Al, the onset potential for hydrogen evolution, and the magnitude of the anodic and cathodic currents. The degree of passivity, which is reflected in the anodic breakdown potential and the magnitude of the anodic current, decreased with increasing solution temperature and HCl concentration, and increased with higher sweep rates. The nature of the Al passivation that occurs during the cathodic half-cycle depends on the cathodic potential limit. These processes and their relationship to the voltammetric curves are discussed in detail.

scholarly journals Non-triangular potential sweep cyclic voltammetry of reversible electron transfer: Experiment meets theory

2018 ◽  
Vol 815 ◽  
pp. 24-29 ◽  
Author(s):  
Hatem M.A. Amin ◽  
Yuki Uchida ◽  
Christopher Batchelor-McAuley ◽  
Enno Kätelhön ◽  
Richard G. Compton
Keyword(s):  
Electron Transfer ◽  
Cyclic Voltammetry ◽  
Transfer Experiment ◽  
Potential Sweep ◽  
Reversible Electron Transfer

New PGE Modified Electrode Comprising Ni NPs/1,5-Diphenylcarbazide Film Capable for Analyzing Oxytocin

2020 ◽  
Vol 18 (11) ◽  
pp. 793-800
Author(s):  
Mahsa JaFari-Pouyani ◽  
Samineh Kaki ◽  
Arash Babakhanian
Keyword(s):  
Cyclic Voltammetry ◽  
Linear Response ◽  
Square Wave Voltammetry ◽  
Limit Of Detection ◽  
Nano Particles ◽  
Square Wave ◽  
Wave Voltammetry ◽  
Microscopy Techniques ◽  
Bare Surface ◽  
Human Blood Serum Sample

This study focuses on the compatibility of square wave voltammetry technique with new modified graphite pencil electrode to quantify Oxytocin. Ni-Nano particles and 1,5-diphenylcarbazide modifiers were quickly electro-deposited by cyclic voltammetry sweeping technique on the bare surface of a graphite pencil electrode. The electrochemical and morphological assessments were accomplished with cyclic voltammetry, square wave voltammetry and scanning electron microscopy techniques. The proposed electrochemical sensor revealed a good electro catalytic response to Oxytocin concerning the parameters α = 0.42, log Ks =3.44 and Γ = 8.72×10−10 in the optimized pH of 4 and the working potential of about 0.35 V. The new sensor also exhibited a linear response to Oxytocin over the concentration range of 125 to 350 nmolL−1 with the limit of detection of 41.53 nmolL−1. Moreover, the applicability of the proposed sensor was successfully examined and it became usable to determine Oxytocin accurately and precisely in real samples such as human blood serum sample without any serious side interference.

Voltammetric behavior and quantification of the anti-leukemia drug imatinib in bulk form, pharmaceutical formulation, and human serum at a mercury electrode

2004 ◽  
Vol 82 (7) ◽  
pp. 1203-1209 ◽  
Author(s):  
E Hammam ◽  
H S El-Desoky ◽  
A Tawfik ◽  
M M Ghoneim
Keyword(s):  
Cyclic Voltammetry ◽  
Human Serum ◽  
Electrochemical Behavior ◽  
Stripping Voltammetry ◽  
Pharmaceutical Formulation ◽  
Myelogenous Leukemia ◽  
Hanging Mercury Drop Electrode ◽  
Square Wave ◽  
Mercury Drop Electrode ◽  
Square Wave Stripping Voltammetry

Imatinib (GleevecTM, ST1571) exemplifies the successful development of a rationally designed molecularly targeted therapy for treatment of a specific cancer. It is a highly promising new drug for the treatment of chronic myelogenous leukemia in blast crisis, in the accelerated or chronic phase after interferon failure or intolerance. The electrochemical behavior of imatinib was studied in Britton–Robinson (B–R) buffers of pH 2 to 11 by means of cyclic voltammetry at a hanging mercury drop electrode. The voltammograms showed a single 2-electron irreversible cathodic peak, which may be attributed to reduction of the C=O double bond of the imatinib molecule. Imatinib exhibited a strong adsorption onto the electrode surface especially in B–R buffers of pH 6 and 7. The adsorptive response of the drug was optimized with respect to the pH of the electrolysis medium, accumulation variables, and instrumental parameters using a square-wave stripping voltammetry technique. A fully validated, simple, sensitive, precise, and selective square-wave adsorptive cathodic stripping voltammetric procedure is described for trace determination of imatinib. The limits of detection (LOD) and quantitation (LOQ) of the bulk imatinib, following preconcentration for 150 s onto the hanging mercury drop electrode, were found to be 2.6 × 10–10 and 8.7 × 10–10 mol/L, respectively. The proposed procedure was successfully applied for quantitation of imatinib in pharmaceutical formulation (Glivec®) and spiked human serum, without the necessity for sample pretreatment or time-consuming extraction or evaporation steps prior to analysis of the drug. LOD and LOQ of 4.6 × 10–10 and 1.5 × 10–9 mol/L, respectively, were achieved after 120 s of preconcentration of the drug spiked in human serum.Key words: imatinib, GleevecTM, Glivec®, ST1571, cyclic voltammetry, square-wave stripping voltammetry, electrochemical behavior, quantification, pharmaceutical formulation, human serum.

scholarly journals Fe2O3 Blocking Layer Produced by Cyclic Voltammetry Leads to Improved Photoelectrochemical Performance of Hematite Nanorods

Surfaces ◽  
2019 ◽  
Vol 2 (1) ◽  
pp. 131-144 ◽  
Author(s):  
Mahshid Poornajar ◽  
Nhat Nguyen ◽  
Hyo-Jin Ahn ◽  
Markus Büchler ◽  
Ning Liu ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Bulk Material ◽  
Anodic Oxide ◽  
Photocurrent Density ◽  
Iron Film ◽  
Blocking Layer ◽  
Photoelectrochemical Performance ◽  
Onset Potential ◽  
Surface And Interface ◽  
Sputter Deposited

Hematite is a low band gap, earth abundant semiconductor and it is considered to be a promising choice for photoelectrochemical water splitting. However, as a bulk material its efficiency is low because of excessive bulk, surface, and interface recombination. In the present work, we propose a strategy to prepare a hematite (α-Fe2O3) photoanode consisting of hematite nanorods grown onto an iron oxide blocking layer. This blocking layer is formed from a sputter deposited thin metallic iron film on fluorine doped tin oxide (FTO) by using cyclic voltammetry to fully convert the film into an anodic oxide. In a second step, hematite nanorods (NR) are grown onto the layer using a hydrothermal approach. In this geometry, the hematite sub-layer works as a barrier for electron back diffusion (a blocking layer). This suppresses recombination, and the maximum of the incident photon to current efficiency is increased from 12% to 17%. Under AM 1.5 conditions, the photocurrent density reaches approximately 1.2 mA/cm2 at 1.5 V vs. RHE and the onset potential changes to 0.8 V vs. RHE (using a Zn-Co co-catalyst).

1,2-Dicyanoferrocene: synthesis and characterization

2016 ◽  
Vol 94 (6) ◽  
pp. 547-551 ◽  
Author(s):  
Mohammad A. Abdulmalic ◽  
Steve W. Lehrich ◽  
Heinrich Lang ◽  
Tobias Rüffer
Keyword(s):  
Cyclic Voltammetry ◽  
Solid State ◽  
Single Crystal ◽  
Square Wave Voltammetry ◽  
Molecular Structures ◽  
Synthesis And Characterization ◽  
X Ray ◽  
Square Wave ◽  
Wave Voltammetry ◽  
Convenient Synthesis

A convenient synthesis of 1,2-dicyanoferrocene (3) was developed by using 2,4-dinitrofluorobenzene as a dehydrating agent for the treatment of 1,2-ferrocenedicarbaldehyde dioxime (2) to give 3 in yields exceeding 80%. Compounds 2 and 3 have been characterized by IR and NMR (1H, 13C{1H}) spectroscopy and by electrochemistry (cyclic voltammetry and square-wave voltammetry). Furthermore, the molecular structures of 2 and 3 in the solid state have been determined by single-crystal X-ray crystallographic studies.

Synthesis and characterization of novel conducting homopolymers based on amino β-styryl terthiophene

2008 ◽  
Vol 86 (11) ◽  
pp. 1010-1018 ◽  
Author(s):  
Hakim Mehenni ◽  
Lê H Dao
Keyword(s):  
Cyclic Voltammetry ◽  
Photoelectron Spectroscopy ◽  
Square Wave Voltammetry ◽  
Covalent Bonding ◽  
Modified Glassy Carbon Electrode ◽  
X Ray ◽  
Square Wave ◽  
Wave Voltammetry ◽  
Amine Groups

Novel ECPs (electronic conducting polymers) based on amino β-styryl-substituted terthiophene (AST) were synthetized by direct electropolymerization. The ECPs were characterized by cyclic voltammetry, square-wave voltammetry, Fourier transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). The poly(amino β-styryl terthiophene) displayed cyclic and square-wave voltammograms with redox peaks that can be assigned to the aminophenyl moiety and the polyterthiophene backbone. The presence of free primary amine groups on the ECP film permitted further biological functionalization (i.e., covalent bonding of various bioreceptors on its surface). The electrochemical performance of Biotin grafted at the AST modified glassy carbon electrode was investigated to detect the Avidin protein in solution by cyclic voltammetry and square-wave voltammetry.Key words: electronic conducting polymer, electrode surface modification, biosensor, β-styryl-substitued terthiophene, functionalization, cyclic, square-wave voltammetry.

INVESTIGATION OF THE CAVITATION AND PRESSURE CHANGE OF BRAIN TISSUE BASED ON A TRANSPARENT HEAD MODEL IN ITS DECELERATING IMPACT

2010 ◽  
Vol 10 (02) ◽  
pp. 361-372 ◽  
Author(s):  
SHENGXIONG LIU ◽  
ZHIYONG YIN ◽  
HUI ZHAO ◽  
GUANGYU YANG
Keyword(s):  
Brain Tissue ◽  
Normal Level ◽  
High Speed ◽  
Pressure Change ◽  
Positive Pressure ◽  
Head Model ◽  
Air Bubbles ◽  
Half Cycle ◽  
Air Bubble ◽  
The Brain

In this paper, a transparent physical head model with air bubbles to simulate the brain cavitation phenomena in head decelerating impact is presented. The transparent skull model was generated based on a real human skull through the turnover formwork technique, and a transparent gel was used to substitute the brain tissue. Air bubbles were created in the gel at the representative sites such as coup site and contrecoup site. After this, the head model was made to free fall from a position and impact on a fixed platform. The decelerating impacting process was recorded by a high-speed video camera and an accelerometer system. Through analyzing the video, the volume change of the air bubbles, namely, the mean pressure change of the air bubbles were calculated and compared. This new method has an advantage in investigating the brain cavitation phenomena using a direct and visual technique. The results showed explicitly and effectively that during the decelerating impact the contrecoup site air bubble was exposed mainly to a negative pressure which value became smaller and smaller in the first half of the impacting cycle and then came near to the normal level in the second half of the cycle; contrarily, the coup site air bubble was exposed mainly to a positive pressure which value became greater and greater in the first half of the impacting cycle and then came near to the normal level in the second half cycle. The probable biomechanics of the cavitation phenomenon is also given in this paper.

scholarly journals Swimming in the Pteropod Mollusc, Clione Umacina: I. Behaviour and Morphology

1985 ◽  
Vol 116 (1) ◽  
pp. 189-204 ◽  
Author(s):  
RICHARD A. SATTERLIE ◽  
MICHAEL LABARBERA ◽  
ANDREW N. SPENCER
Keyword(s):  
Reynolds Number ◽  
High Speed ◽  
Half Cycle ◽  
Velocity Measurements ◽  
Wing Movement ◽  
Friday Harbor ◽  
Maximal Angle ◽  
Clione Limacina ◽  
Muscle Groups ◽  
Wing Tips

In the pteropod mollusc Clione limacina (Phipps), swimming is accomplished through alternate dorsal and ventral flexions of a pair of strongly muscularized wing-like parapodia (wings). Wing musculature is arranged in seven muscle groups. The two outer most dorsal and ventralgroups produce the bending movements of swimming. The three innermuscle groups include longitudinal and transverse wing retractors and dorsoventral muscles. The overall muscle arrangement is similar to that of the generalized mollusc foot. During hovering locomotion the wings pronate on downstroke and supinate on upstroke to produce a maximal angle of attack of 42° for both phases. Wing tips nearly touch or overlap in the saggital plane at the extreme of each half-cycle. High speed movie analysis of hovering swimming indicates that upstroke and downstroke are nearly symmetrical. It is suggested that wings produce lift in both wing phases. We estimate from wing dimensions and velocity measurements that the Reynolds number of the wings is approximately 200. A novel lift-generating mechanism, similar to the ‘clap-and-fling’ of insects, may be utilized by the Clione wing to generate lift throughout the wing cycle despite the reversal of wing movement in each half-stroke. Note: A significant portion of this work was conducted at Friday Harbor Laboratories, Friday Harbor, Washington.

Sign in / Sign up

Export Citation Format

Share Document