scholarly journals Ashwagandha Extract as Green Sustainable Corrosion Inhibitor for Aluminum in Acidic Solutions

2020 ◽  
Vol 11 (2) ◽  
pp. 9719-9734
Keyword(s):  
Corrosion Inhibitor ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Effect Of Temperature ◽  
Aluminum Surface ◽  
Force Microscopy ◽  
Atomic Force ◽  
Hydrochloric Acid Solutions ◽  
Good Accord ◽  
Surface Examination

In this study, the employment of Ashwagandha extract (AE) as a green sustainable corrosion inhibitor for aluminum in one molar hydrochloric acid solutions was examined utilizing “mass loss (ML), electrochemical frequency modulation (EFM), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PP) measurements”. The surface examination was analyzed utilizing atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) analysis. The effect of temperature on corrosion demeanor with adding a different dose of AE was investigated within the temperature varieties of 25-45 ºC by ML strategy. The curves of polarization reveal that AE is considered as a mixed sort inhibitor. The performance of inhibition rises with raising the AE concentration and diminished with the temperature ascending. The adsorption of the inhibitor on aluminum surface complies with the Langmuir’s adsorption isotherm and is considered as physisorption. The outcomes attained from chemical and electrochemical methods are in good accord.

Synergistic effect of polyvinylpyrrolidone noncovalently modified graphene and epoxy resin in anticorrosion application

2020 ◽  
pp. 095400832094229
Author(s):  
Shifeng Wen ◽  
Jiacheng Ma
Keyword(s):  
Epoxy Resin ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Covalent Modification ◽  
Original Structure ◽  
Graphene Layers ◽  
Force Microscopy ◽  
Atomic Force ◽  
The Stability ◽  
Modified Graphene

In this article, polyvinylpyrrolidone (PVP) was used for the noncovalent modification on the surface of graphene. Compared with covalent modification, this method maintained the original structure of graphene layers, thereby maximizing the original properties of graphene. The π–π noncovalent bond was formed between PVP and graphene by X-ray photoelectron spectroscopy analysis, indicating that PVP successfully modified graphene. The thickness of graphene layer was measured by atomic force microscopy, which showed that the distance between graphene layers was increased by 5–6 nm, and the stability of the modified graphene in N, N-dimethylformamide was remarkably improved. The obtained composite coating by combination of the modified graphene and the epoxy resin was subjected to electrochemical impedance test to obtain the best anticorrosive effect of the coating with the graphene content of 0.3 wt%. The results showed that the addition of graphene to the epoxy resin could effectively improve the anticorrosive effect. Meanwhile, the good electrical conductivity allowed the electrons which lost from the substrate to led to air or saline rapidly, thereby reducing the combination of iron ions with oxygen and the generation of corrosion products (iron oxides).

scholarly journals Enhancing the corrosion resistance of reinforcing steel under aggressive operational conditions using behentrimonium chloride

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
A. Bahgat Radwan ◽  
Mostafa H. Sliem ◽  
Noor S. Yusuf ◽  
Nasser A. Alnuaimi ◽  
Aboubakr M. Abdullah
Keyword(s):  
Mechanical Properties ◽  
Corrosion Rate ◽  
Photoelectron Spectroscopy ◽  
Inhibition Efficiency ◽  
Electrochemical Impedance ◽  
Reinforcing Steel ◽  
Operational Conditions ◽  
Force Microscopy ◽  
Acidic Gases ◽  
Atomic Force

AbstractAggressive operational conditions e.g. saline media and acidic gases, e.g., CO2 can increase the corrosion rate of reinforcing steel. Accordingly, the necessity to protect the steel under the above conditions without affecting the mechanical properties of the concrete is growing. Herein, the inhibition efficiency of a new corrosion inhibitor, behentrimonium chloride (BTC, C25H54ClN), is explored in a simulated-concrete pore solution (SCP) with 3.5 wt.% NaCl at different pH using electrochemical impedance spectroscopy (EIS) and polarization methods. Using only a 50 μmol L−1 of BTC, we are able to measure an inhibition efficiency of 91, 79, and 71% in SCP solution with 3.5% NaCl at pH of 12.5, 10 and 7, respectively without showing any effect on the mechanical properties on the cured mortars. Temkin isotherm is used to describe the physisorption of BTC inhibitor on the steel surface. Also, the adsorption and influence of the inhibitor on the metal surface are characterized using the scanning electron microscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. In conclusion, this new inhibitor shows high corrosion inhibition efficiencies under different aggressive conditions and can be used in concrete to reduce the corrosion rate of reinforcing steel without decreasing the mechanical properties of the concrete.

scholarly journals Plantago Major Extract as an Environmentally Friendly Inhibitor for the Corrosion of L-80 Carbon Steel in 0.5 M H2SO4 Media

2021 ◽  
Vol 11 (4) ◽  
pp. 12186-12201
Keyword(s):  
Carbon Steel ◽  
Electrochemical Impedance ◽  
Plantago Major ◽  
Force Microscopy ◽  
Atomic Force ◽  
Good Accord ◽  
Ft Ir ◽  
Ir Analysis ◽  
Loss Method ◽  
Increasing Temperature

The inhibition impact of Plantago major leaves extract on carbon steel (CS) which immersed in 0.5 M H2SO4 media was ‎investigated by several methods such as mass loss method (ML), electrochemical impedance spectroscopy (EIS), potentiodynamic ‎polarization (PDP), and electrochemical frequency modulation‎ (EFM). Data obtained from different measurements was showed that %IE enhanced with added the Plantago major extract doses also increased with increasing temperature degree. Thermodynamic adsorption and kinetic parameters of the system were also measured and studied. The ‎adsorption of the Plantago major extract on CS is, according to Temkin isotherm. The ‎ curves from PDP explained that the Plantago major extract is considered as a mixed-type inhibitor. The EIS technique's acquired data verified that the studied extract produced a thin layer that covers and protects the CS surface. Atomic ‎Force Microscopy (AFM) and Fourier Transform Infrared (FT-IR) analysis conformed that Plantago major extract was adsorbed on CS surface. The data obtained from unlike measurements were in good accord.

scholarly journals Chemical, electrochemical and surface morphology investigation of Cichorium intybus extract (CIE) as beneficial inhibitor for Al in 2 M HCl acid

2020 ◽  
Vol 9 (2) ◽  
pp. 1064-1073
Keyword(s):  
Surface Morphology ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Inhibition Mechanism ◽  
X Ray ◽  
Force Microscopy ◽  
Tafel Polarization ◽  
Atomic Force ◽  
Chemical Strategies ◽  
Hcl Medium

The inhibiting activity of CIE(CIE) to the dissolution of Al in 2M HCl medium was carried out by chemical strategies (mass loss and gasometry) and electrochemical systems, for example, tafel polarization (TP), electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM). Surface morphology was examined utilizing atomic force microscopy (AFM) and x-ray photoelectron spectroscopy (XPS). Fourier transform infrared spectroscopy (FTIR) outcomes indicated that the inhibition mechanism was by adsorption process through the functional groups that exist in the investigated extract. The results demonstrated that the inhibiting efficiency expanded with expanding amounts of the extract. Polarization information demonstrated that CIE goes about as an inhibitor of mixed type. The procedure of adsorption on Al surface ascribed to Langmuir isotherm. All thermodynamic calculations were determined and discussed. The inhibitive efficiencies obtained from all utilized procedures have acceptable values.

scholarly journals Experimental and Theoretical Study of the Covalent Grafting of Triazole Layer onto the Gold Surface

Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2927
Author(s):  
Nimet Orqusha ◽  
Sereilakhena Phal ◽  
Avni Berisha ◽  
Solomon Tesfalidet
Keyword(s):  
Photoelectron Spectroscopy ◽  
Density Functional ◽  
Electrochemical Impedance ◽  
Gold Surface ◽  
Covalent Attachment ◽  
Force Microscopy ◽  
Atomic Force ◽  
Covalent Grafting ◽  
Before And After

Finding novel strategies for surface modification is of great interest in electrochemistry and material sciences. In this study, we present a strategy for modification of a gold electrode through covalent attachment of triazole (TA) groups. Triazole groups were electrochemically grafted at the surface of the electrode by a reduction of in situ generated triazolediazonium cations. The resulting grafted surface was characterized before and after the functionalization process by different electrochemical methods (cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS)) confirming the presence of the grafted layer. The grafting of TA on the electrode surface was confirmed using analysis of surface morphology (by atomic force microscopy), the thickness of the grafted layer (by ellipsometry) and its composition (by X-ray photoelectron spectroscopy). Density functional theory (DFT) calculations imply that the grafted triazole offers a stronger platform than the grafted aryl layers.

scholarly journals Towards Understanding the Role of Surface Gas Nanostructures: Effect of Temperature Difference Pretreatment on Wetting and Flotation of Sulfide Minerals and Pb-Zn Ore

Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1362
Author(s):  
Yuri Mikhlin ◽  
Anton Karacharov ◽  
Sergey Vorobyev ◽  
Alexander Romanchenko ◽  
Maxim Likhatski ◽  
...  
Keyword(s):  
Temperature Difference ◽  
Photoelectron Spectroscopy ◽  
Sessile Drop ◽  
Surface Composition ◽  
Cold Water ◽  
Contact Angles ◽  
Effect Of Temperature ◽  
Force Microscopy ◽  
Atomic Force ◽  
Composition Of Minerals

Surface nanobubbles at hydrophobic interfaces now attract much attention in various fields but their role in wetting-related phenomena is still unclear. Herein, we report the effect of a preliminary contact of “hot” solids with cold water previously proposed for generation of surface nanobubbles, on wettability of compact materials and flotation of particulate galena (PbS), sphalerite (ZnS), and Pb-Zn sulfide ore. Atomic force microscopy was applied to visualize the nanobubbles at galena crystals heated in air and contacted with cold water; X-ray photoelectron spectroscopy was used to characterize the surface composition of minerals. Contact angles measured with the sessile drop of cold water were found to increase when enhancing the support temperature from 0 to 80 °C for sphalerite and silica, and to pass a maximum at 40–60 °C for galena and pyrite (FeS2) probably due to oxidation of sulfides. The temperature pretreatment depressed the recovery of sulfides in collectorless schemes and improved the potassium butyl xanthate-assisted flotation both for single minerals and Gorevskoye Pb-Zn ore. The results suggest that the surface nanobubbles prepared using the temperature difference promote flotation if minerals are rather hydrophobic and insignificantly oxidized, so the addition of collector and activator (for sphalerite) is necessary.

Investigation of the Effect of Uv-Assisted Oxidation and Nitridation of Hafnium Metal Films

2003 ◽  
Vol 780 ◽  
Author(s):  
C. Essary ◽  
V. Craciun ◽  
J. M. Howard ◽  
R. K. Singh
Keyword(s):  
Uv Radiation ◽  
Photoelectron Spectroscopy ◽  
Grazing Angle ◽  
X Ray Diffraction ◽  
Metal Thin Films ◽  
X Ray ◽  
Force Microscopy ◽  
Si Substrates ◽  
Atomic Force ◽  
Silicon Interface

AbstractHf metal thin films were deposited on Si substrates using a pulsed laser deposition technique in vacuum and in ammonia ambients. The films were then oxidized at 400 °C in 300 Torr of O2. Half the samples were oxidized in the presence of ultraviolet (UV) radiation from a Hg lamp array. X-ray photoelectron spectroscopy, atomic force microscopy, and grazing angle X-ray diffraction were used to compare the crystallinity, roughness, and composition of the films. It has been found that UV radiation causes roughening of the films and also promotes crystallization at lower temperatures.Furthermore, increased silicon oxidation at the interface was noted with the UVirradiated samples and was shown to be in the form of a mixed layer using angle-resolved X-ray photoelectron spectroscopy. Incorporation of nitrogen into the film reduces the oxidation of the silicon interface.

scholarly journals Photocatalytic reduction of graphene oxide with cuprous oxide film under UV-vis irradiation

2020 ◽  
Vol 59 (1) ◽  
pp. 207-214 ◽  
Author(s):  
Yao Wang ◽  
Jianqing Feng ◽  
Lihua Jin ◽  
Chengshan Li
Keyword(s):  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Low Cost ◽  
Photocatalytic Reduction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Reduced Graphene ◽  
Reduction Efficiency ◽  
Metal Organic ◽  
Reduction Effect

AbstractWe have grown Cu2O films by different routes including self-oxidation and metal-organic deposition (MOD). The reduction efficiency of Cu2O films on graphene oxide (GO) synthesized by modified Hummer’s method has been studied. Surface morphology and chemical state of as-prepared Cu2O film and GO sheets reduced at different conditions have also been investigated using atomic force microscopy (AFM) and x-ray photoelectron spectroscopy (XPS). Results show that self-oxidation Cu2O film is more effective on phtocatalytic reduction of GO than MOD-Cu2O film. Moreover, reduction effect of self-oxidation Cu2O film to GO is comparable to that of environmental-friendly reducing agent of vitamin C. The present results offer a potentially eco-friendly and low-cost approach for the manufacture of reduced graphene oxide (RGO) by photocatalytic reduction.

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