Influence of over-discharge on the lifetime and performance of LiFePO4/graphite batteries

In this study, the degradation of a LiFePO₄/graphite battery under an over-discharge process and its effect on further cycling stability are investigated.

Strychnos nuxvomica, Piper longum and Mucuna pruriens seed extracts as eco-friendly corrosion inhibitors for copper in nitric acid

The inhibitive effect of the Strychnos nuxvomica (SN), Piper longum (PL) and Mucuna pruriens (MP) seeds extract on the corrosion of copper in 3 M HNO₃ solution was studied using gravimetric and electrochemical techniques.

Corrosion Behavior of Cast Iron in Freely Aerated Stagnant Arabian Gulf Seawater

In this work, the results obtained from studying the corrosion of cast iron in freely aerated stagnant Arabian Gulf seawater (AGS) at room temperature were reported. The study was carried out using weight-loss (WL), cyclic potentiodynamic polarization (CPP), open-circuit potential (OCP), and electrochemical impedance spectroscopy (EIS) measurements and complemented by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) investigations. WL experiments between two and 10 days’ immersion in the test electrolyte indicated that the weight-loss the cast iron increases with increasing the time of immersion. CPP measurements after 1 h and 24 h exposure period showed that the increase of time decreases the corrosion via decreasing the anodic and cathodic currents, as well as decreasing the corrosion current and corrosion rate and increasing the polarization resistance of the cast iron. EIS data confirmed the ones obtained by WL and CPP that the increase of immersion time decreases the corrosion of cast iron by increasing its polarization resistance.

Evaluating two new Schiff bases synthesized on the inhibition of corrosion of copper in NaCl solutions

An AND or DSM organic film can be formed onto a copper surface in 3% NaCl solution and acts as a barrier to copper dissolution and O₂reduction.

Study on the efficiency of some amine derivatives as corrosion and scale inhibitors in cooling water systems

A study on the corrosion and scaling inhibition efficiencies of some amine derivatives for carbon steel.

Insights into the corrosion inhibition of copper in hydrochloric acid solution by self-assembled films of 4-octylphenol

4-Octylphenol was used to form self-assembled films on copper to inhibit its corrosion in 0.5 M HCl solution.

The corrosion inhibition effect of aryl pyrazolo pyridines on copper in hydrochloric acid system: computational and electrochemical studies

The inhibition effect of three aryl pyrazole pyridine derivatives (APPs) against the corrosion of copper in 0.5 M HCl has been investigated by electrochemical impedance, potentiodynamic polarization measurements and quantum chemical methods.

Hydroxyethylcellulose used as an eco-friendly inhibitor for 1018 c-steel corrosion in 3.5% NaCl solution

The inhibition effect of hydroxyethylcellulose (HEC) on 1018 c-steel corrosion in 3.5% NaCl solution was investigated by using potentiodynamic polarization, electrochemical frequency modulation (EFM) and electrochemical impedance spectroscopy (EIS) techniques. The potentiodynamic polarization studies suggested that HEC acts as a mixed-type inhibitor. Data obtained from EIS were analyzed to model the corrosion inhibition process through equivalent circuit. Results obtained from EFM technique were shown to be in agreement with potentiodynamic and EIS techniques. The adsorption behavior of HEC on steel surface follows the Langmuir adsorption isotherm. Thermodynamic parameter (ΔG°(ads)) and activation parameters (Ea(*), ΔH(*) and ΔS(*)) were calculated to investigate mechanism of inhibition. Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis system were performed to characterize the film formed on the metal surface. DMol(3) quantum chemical calculations were performed to support the adsorption mechanism with the structure of HEC molecule.

Some Thiophene Derivatives as Corrosion Inhibitors for Carbon Steel in Hydrochloric Acid

Corrosion inhibitive performance of some thiophene derivatives during the acidic corrosion of carbon steel surface in 1 M HCl was investigated by chemical technique (weight loss) and electrochemical techniques (potentiodynamic polarization, electrochemical frequency modulation, and electrochemical impedance spectroscopy). The effect of temperature on the corrosion rate was investigated by the weight loss method, and some thermodynamic parameters for corrosion and adsorption processes were determined and discussed. The results show that the inhibition efficiency increased with the increase in inhibitor concentration and temperature. The adsorption of thiophene derivatives on the carbon steel surface obeys Langmuir adsorption isotherm. The obtained results indicated that the investigated compounds are chemically adsorbed on the steel surface. Potentiodynamic polarization studies showed that these compounds are mixed-type inhibitors and the results obtained from the techniques are in good agreement.

Synthesis and evaluation of poly(Sodium 2-Acrylamido-2-Methylpropane Sulfonate-co-Styrene)/magnetite nanoparticle composites as corrosion inhibitors for steel

Self-stabilized magnetic polymeric composite nanoparticles of coated poly-(sodium 2-acrylamido-2-methylpropane sulfonate-co-styrene)/magnetite (PAMPS-Na-co-St/Fe3O4) were prepared by emulsifier-free miniemulsion polymerization using styrene (St) as a monomer, 2-acrylamido-2-methylpropane sulfonic acid sodium salt (AMPS-Na) as an ionic comonomer, N,N-methylenebisacrylamide (MBA) as crosslinker, hexadecane (HD) as a hydrophobic solvent, and 2,2-azodiisobutyronitrile (AIBN) as an initiator in the presence of hydrophobic oleic acid coated magnetite particles. Hydrophobic oleic acid coated magnetite particles with an average size of about 7-10 nm were prepared with the new modified water-based magnetite ferrofluid, synthesized by a chemical modified coprecipitation method. The morphology and the particle size distributions of the crosslinked PAMPS-Na-co-St/Fe3O4 composite were observed and analyzed by transmission electron microscopy (TEM). The average Fe3O4 content of PAMPS-Na-co-St/Fe3O4 was determined by thermogravimetric analysis (TGA). The inhibitory action of PAMPS-Na-co-St/Fe3O4 towards steel corrosion in 1 M HCl solutions has been investigated by polarization and electrochemical impedance spectroscopy (EIS) methods. Polarization measurements indicate that PAMPS-Na-co-St/Fe3O4 acts as a mixed type-inhibitor and the inhibition efficiency increases with inhibitor concentration. The results of potentiodynamic polarization and EIS measurements clearly showed that the inhibition mechanism involves blocking of the steel surface by inhibitor molecules via adsorption.

Synthesis and evaluation of poly(Sodium 2-Acrylamido-2-Methylpropane Sulfonate-co-Styrene)/magnetite nanoparticle composites as corrosion inhibitors for steel

Self-stabilized magnetic polymeric composite nanoparticles of coated poly-(sodium 2-acrylamido-2-methylpropane sulfonate-co-styrene)/magnetite (PAMPS-Na-co-St/Fe3O4) were prepared by emulsifier-free miniemulsion polymerization using styrene (St) as a monomer, 2-acrylamido-2-methylpropane sulfonic acid sodium salt (AMPS-Na) as an ionic comonomer, N,N-methylenebisacrylamide (MBA) as crosslinker, hexadecane (HD) as a hydrophobic solvent, and 2,2-azodiisobutyronitrile (AIBN) as an initiator in the presence of hydrophobic oleic acid coated magnetite particles. Hydrophobic oleic acid coated magnetite particles with an average size of about 7-10 nm were prepared with the new modified water-based magnetite ferrofluid, synthesized by a chemical modified coprecipitation method. The morphology and the particle size distributions of the crosslinked PAMPS-Na-co-St/Fe3O4 composite were observed and analyzed by transmission electron microscopy (TEM). The average Fe3O4 content of PAMPS-Na-co-St/Fe3O4 was determined by thermogravimetric analysis (TGA). The inhibitory action of PAMPS-Na-co-St/Fe3O4 towards steel corrosion in 1 M HCl solutions has been investigated by polarization and electrochemical impedance spectroscopy (EIS) methods. Polarization measurements indicate that PAMPS-Na-co-St/Fe3O4 acts as a mixed type-inhibitor and the inhibition efficiency increases with inhibitor concentration. The results of potentiodynamic polarization and EIS measurements clearly showed that the inhibition mechanism involves blocking of the steel surface by inhibitor molecules via adsorption.

Corrosion and Corrosion Inhibition of High Strength Low Alloy Steel in 2.0 M Sulfuric Acid Solutions by 3-Amino-1,2,3-triazole as a Corrosion Inhibitor

The corrosion and corrosion inhibition of high strength low alloy (HSLA) steel after 10 min and 60 min immersion in 2.0 M H2SO4solution by 3-amino-1,2,4-triazole (ATA) were reported. Several electrochemical techniques along with scanning electron microscopy (SEM) and energy dispersive X-ray (EDS) were employed. Electrochemical impedance spectroscopy indicated that the increase of immersion time from 10 min to 60 min significantly decreased both the solution and polarization resistance for the steel in the sulfuric acid solution. The increase of immersion time increased the anodic, cathodic, and corrosion currents, while it decreased the polarization resistance as indicated by the potentiodynamic polarization measurements. The addition of 1.0 mM ATA remarkably decreased the corrosion of the steel and this effect was found to increase with increasing its concentration to 5.0 mM. SEM and EDS investigations confirmed that the inhibition of the HSLA steel in the 2.0 M H2SO4solutions is achieved via the adsorption of the ATA molecules onto the steel protecting its surface from being dissolved easily.

Spectral study of the interaction between 2-pyridinecarbaldehyde-p-phenyldihydrazone and ferric iron and its analytical application

The synthesis and spectral characterization of a schiff base, 2-pyridinecarbaldehyde-p-phenylenedihydrazone (short for 2PC-PPH), were described. It was found that ferric ion (Fe(3+)) could selectively quench the fluorescence of 2PC-PPH, whereas many other metal ions, such as Mn(2+), Zn(2+), Cu(2+), K(+), Al(3+), Ca(2+), Ni(2+), Co(2+), Cr(3+) and Fe(2+), could not quench its fluorescence. Based on this, a sensitive method for ferric ion selective detection was established. Under the optimum conditions, the decreasing fluorescence intensity of 2PC-PPH is proportional to the concentration of Fe(3+) within the range of 6.0×10(-7)-1.0×10(-5) mol L(-1). The detection limit (3σ) for Fe(3+) determination is 3.6×10(-7) mol L(-1). The proposed method was successfully applied to determine iron in tea and milk powder.

Corrosion resistant performances of alkanoic and phosphonic acids derived self-assembled monolayers on magnesium alloy AZ31 by vapor-phase method

Alkanoic and phosphonic acid derived self-assembled monolayers (SAMs) were formed on magnesium alloy by the vapor phase method. AFM and XPS studies showed that SAMs were formed on Mg alloy. The chemical and anticorrosive properties of the SAMs prepared on magnesium alloys were characterized using contact angle measurements, X-ray photoelectron spectroscopy (XPS), and electrochemical measurements. Water contact angle measurements revealed that, although SA and ISA have the same headgroup to anchor to the magnesium alloy surface, the packing density on the magnesium alloy surface could be considerably different. The contact angle hysteresis of SAMs with a carboxylate headgroup is much larger than that of SAMs with a phosphonic acid group. The XPS O 1s peaks indicated more likely a mix of mono-, bi-, or tridentate binding of phosphonic acid SAM to the oxide or hydroxide surface of the Mg alloy. The electrochemical measurements showed that the phosphonic acid derived SAM had better corrosion resistance compared to alkanoic acid derived SAM. The chemical stability of SAMs modified magnesium alloy was investigated using water contact angle and XPS measurements. The water contact angle and XPS measurements revealed that the molecular density of OP and PFEP on magnesium alloy would be higher than those of SA and ISA on magnesium alloy.

Electrochemical Study on Corrosion Inhibition of Copper in Hydrochloric Acid Medium and the Rotating Ring-Disc Voltammetry for Studying the Dissolution

Dissolution characteristics of copper in hydrochloric acid medium and the effect of 4-amino 1,2,4-triazole (ATA) on the corrosion process have been studied using conventional electrochemical techniques and rotating ring-disc electrodes (RRDEs). Corrosion potential () and corrosion current density () were obtained by Tafel extrapolation methods. Charge transfer resistance () and double-layer capacitance () were obtained from the electrochemical impedance spectroscopy (EIS). ATA was shown to be an effective inhibitor for the copper-corrosion inhibition in acid medium. The corrosion rate was retarded in presence of inhibitors mainly because of the adsorption of the inhibitor on the electrode surface. Adsorption of the inhibitor on the metal surface was found to follow the Langmuir adsorption isotherm. Standard free energy change of the adsorption process () was calculated to be −54.3 kJ mol−1; such a large negative value of suggests the prescence of a chemisorption process.