Search for: electrochemical-corrosion
0.006 seconds
Total 59 records

    Fabrication of self-organised highly ordered titanium oxide nanotube arrays by anodic oxidation and characterisation

    , Article International Journal of Nanomanufacturing ; Volume 5, Issue 3-4 , 2010 , Pages 297-309 ; 17469392 (ISSN) Mohammadpour, R ; Ahadian, M. M ; Iraji Zad, A ; Taghavinia, N ; Dolati, A. G ; Sharif University of Technology
    Self-organised and vertically oriented titanium oxide nanotube array (TNTA) has been synthesised by potentiostat anodisation of Ti foil in fluoride-based electrolyte. By varying the anodisation voltage from 8 V to 24 V it was possible to gradually change the topologies of nanotubes. The size of TNTAs was measured using SEM images and also determined based on a non-destructive optical method. In addition, photoelectrochemical properties of nanotubular TiO2/Ti electrodes were examined by anodic photocurrent response, potentiodynamic polarisation measurements and electrochemical impedance spectroscopy. A general equivalent circuit model was proposed for photoelectrochemical system consists of... 

    Modelling of carbon dioxide corrosion of steel with iron carbonate precipitation

    , Article Corrosion Engineering Science and Technology ; Volume 44, Issue 2 , 2009 , Pages 128-136 ; 1478422X (ISSN) Shayegani, M ; Ghorbani, M ; Afshar, A ; Rahmaniyan, M ; Sharif University of Technology
    Corrosion of mild steel in aqueous solutions containing carbon dioxide was modelled under condition that protective iron carbonate films formed on the steel surface. In this model, the film form on the steel surface due to precipitation of iron carbonate from saturated solution. The precipitation of iron carbonate produces a porous layer on the steel surface, reducing the diffusion of species toward the steel surface. If the precipitation rate is high, the porosity decreases and the mass transport becomes slower. Therefore, formation of protective layers on the steel surface reduces the corrosion rate. In this case, the corrosion processes are controlled with diffusion of species. The model... 

    Cluster/polarized continuum models for density functional theory investigations of benzimidazole corrosion inhibitors at metal/solution interface

    , Article Corrosion ; Volume 62, Issue 3 , 2006 , Pages 199-206 ; 00109312 (ISSN) Lashgari, M ; Arshadi, M. R ; Parsafar, Gh. A ; Sastri, U. S ; Sharif University of Technology
    National Assoc. of Corrosion Engineers International  2006
    The molecular behavior of some benzimidazole (C7H 6N2) derivatives as corrosion inhibitors ojiron in hydrochloric acid (HCl) solution was investigated quantum electrochemically via the inhibitors' chemical potential (μ), molecular softness (σ), and the extent of charge transfer from the inhibitor to the metal (ΔN). These quantities were obtained from density functional theory (DFT) calculations for three models, i.e., isolated inhibitors (in vacua), inhibitors in solution, and, finally, inhibitors in electrical double layer (EDL). In these models, the effects of solvent, substrate, and electric field were considered using a polarized continuum model, iron Fe13(9,4) cluster, and a... 

    Electrodeposition of Ni-Fe-Co alloy nanowire in modified AAO template

    , Article Materials Chemistry and Physics ; Volume 91, Issue 2-3 , 2005 , Pages 417-423 ; 02540584 (ISSN) Saedi, A ; Ghorbani, M ; Sharif University of Technology
    Anodic aluminum oxide (AAO) was used as a template to prepare highly ordered Ni-Fe-Co alloy nanowire arrays. This membrane was fabricated with two-step anodizing method. It is found that there is an optimum barrier thickness to obtain a successful electrodeposition in pores of AAO. The thickness of barrier layer can be modified by additional electrochemical process after completing the anodizing step. Barrier layer thinning can create a rooted structure at the bottom side of the AAO pores and the electrodeposited nanowire arrays. The triple Ni-Fe-Co alloy was deposited in AAO membrane by ac voltage in a simple sulfate bath. The composition of nanowires shows anomalous deposition features... 

    Electrochemical behavior of S-doped nanostructured TiO2 layer synthesized with PEO process for photocatalytic applications

    , Article Advanced Materials Research ; Volume 829 , 2014 , Pages 487-491 ; ISSN: 10226680 ; ISBN: 9783037859070 Ahmadzadeh, M ; Ghorbani, M ; Sharif University of Technology
    Sulfur doped and pure micro-nanoporous TiO2 film were synthesized with PEO method to produce a film with a high surface area for photocatalysis applications. The effect of applied voltage and electrolyte concentration on the microstructure and photocatalytic properties of the prepared layer were investigated via SEM, XRD, EIS and DRS studies. Electrochemical Impedance Spectroscopy (EIS) was carried out in order to determine the corrosion and electrochemical properties of the produced layer. It was found that although the barrier layer resistance decreases with the voltage, the layers porosity and consequently the surface area increases. Finally the XRD and DRS spectrums were correlated with... 

    A model for the evolution of concrete deterioration due to reinforcement corrosion

    , Article Mathematical and Computer Modelling ; Volume 52, Issue 9-10 , November , 2010 , Pages 1403-1422 ; 08957177 (ISSN) Shodja, H. M ; Kiani, K ; Hashemian, A ; Sharif University of Technology
    One of the most crucial factors affecting the service life of reinforced concrete (RC) structures attacked by aggressive ions is reinforcement corrosion. As the steel corrosion progresses, crack propagation in concrete medium endangers the serviceability and the strength of RC structural members. In this study, a nonlinear mathematical model for determining the displacement and stress fields in RC structures subjected to reinforcement corrosion is introduced. For corrosion products, a nonlinear stress-strain relation which has been previously confirmed by experimental data is incorporated in the present analysis. In formulation of the governing equations for steel-rust-concrete composite,... 

    Multistep reduction of oxygen on polycrystalline silver in alkaline solution

    , Article Cuihua Xuebao/Chinese Journal of Catalysis ; Volume 31, Issue 5 , 2010 , Pages 541-546 ; 02539837 (ISSN) Jafarian, M ; Gobal, F ; Mahjani, M. G ; Hosseini Aliabadi, M ; Sharif University of Technology
    Oxygen reduction on a polycrystalline silver electrode was studied by cyclic voltammetry and electrochemical impedance spectroscopy. The reaction occurred by a two-electron pathway. The steps in the mechanism were observed in the cyclic voltammograms recorded with different scan rates. The intermediates formed in the steps were detected by electrochemical impedance spectroscopy  

    Anodizing behavior and electrochemical evaluation of accumulative roll bonded Al and Al-SiC composite

    , Article Surface and Coatings Technology ; Volume 408 , 2021 ; 02578972 (ISSN) Ebadi, M ; Alishavandi, M ; Paydar, M. H ; Sharif University of Technology
    Elsevier B.V  2021
    Accumulative roll bonded (ARBed) AA1050 and Al-2 vol% SiCp (AMC) samples were anodized in an H2SO4 electrolyte to improve corrosion resistance. The SEM images revealed that the anodic oxide's morphology is significantly dependent on the microstructure of the ARBed bare samples, owing to high internal energy that accelerates Al consumption during anodizing process. Potentiodynamic polarization measurements and EIS evaluation showed that anodic oxide improves the corrosion resistance of both ARBed AA and AMC samples; however, the electrochemical behavior of the processed samples changed due to the formation of a complex oxide structure comprising of twisted pore channels and attack routes. ©... 

    Epoxy nanocomposite coatings with enhanced dual active/barrier behavior containing graphene-based carbon hollow spheres as corrosion inhibitor nanoreservoirs

    , Article Corrosion Science ; Volume 185 , 2021 ; 0010938X (ISSN) Haddadi, S. A ; Ramazani Saadatabadi, A ; Mahdavian, M ; Arjmand, M ; Sharif University of Technology
    Elsevier Ltd  2021
    Graphene-based carbon hollow spheres (CHSs) fabrication, doped with 2-mercaptobenzimidazole (MBI) was successfully done in previous work. The active/barrier corrosion protection performance (CPP) of epoxy coatings was evaluated using salt spray test, electrochemical impedance spectroscopy (EIS), and scanning vibrating electrode technique (SVET). Results proved the active/barrier CPP enhancement of epoxy coatings in the presence of 3 wt. % MBI@CHSs. While the presence of MBI and empty CHSs in epoxy coatings did not further improve the active performance. An improvement in the adhesion loss of the epoxy coating, ca. 58 %, was observed in the presence of 3 wt. % MBI@CHSs. © 2021  

    Influence of annealing on the electrochemical behavior of finemet amorphous and nanocrystalline alloy

    , Article Journal of Materials Science ; Volume 45, Issue 2 , 2010 , Pages 546-551 ; 00222461 (ISSN) Asghari Shivaee, H ; Nozad Golikand, A ; Madaah Hosseini, H. R ; Asgari, M ; Sharif University of Technology
    The electrochemical corrosion behavior of finemet alloy at various heat treatment temperatures was investigated. Thermal behavior and structural changes were studied using differential scanning calorimetry and X-ray diffractometry, respectively. The electrochemical corrosion of amorphous and annealed samples was investigated in 0.10 M NaOH solution using electrochemical impedance spectroscopy and linear sweep voltammetery. Changes in morphology of the samples before and after corrosion were characterized using optical microscope. The results showed that structural relaxation and nanocrystallization during the heat treatment improved corrosion behavior of the alloy. The heat-treated alloy at... 

    A comparative investigation of the electrocatalytic oxidation of methanol on poly-NiTCPP and poly-TCPP/Ni modified glassy carbon electrodes

    , Article Journal of Electroanalytical Chemistry ; Volume 663, Issue 1 , December , 2011 , Pages 14-23 ; 15726657 (ISSN) Jafarian, M ; Haghighatbin, M. A ; Gobal, F ; Mahjani, M. G ; Rayati, S ; Sharif University of Technology
    Electro-oxidation of methanol in alkaline solution at a glassy carbon electrode electrochemically modified by a conductive polymeric meso-tetra(4-carboxyphenyl)porphyrinato nickel(II), abbreviated as poly-NiTCPP and also meso-tetra(4-carboxyphenyl)porphyrin with incorporated nickel(II) cations, abbreviated as, poly-TCPP/Ni, were investigated and compared. Both films were prepared by oxidative electro-polymerization of complexes by repetitive cyclic voltammetry (RCV) in 0.1 M NaOH aqueous solution. The electrochemical properties and behaviors and also kinetic values of both films have been characterized and compared using cyclic voltammetry (CV), chronoamperometry (CA) and electrochemical... 

    Prediction of the penetrated rust into the microcracks of concrete caused by reinforcement corrosion

    , Article Applied Mathematical Modelling ; Volume 35, Issue 5 , 2011 , Pages 2529-2543 ; 0307904X (ISSN) Kiani, K ; Shodja, H. M ; Sharif University of Technology
    Consider a steel-rust-concrete composite consisting of a circular cylindrical concrete cover and a coaxial uniformly corroding steel reinforcement. Prediction of the amount of rust penetrated into the microcracks of concrete cover from a set of data measured at the surface of the concrete is of particular interest. The steel is assumed to be linear isotropic and rust follows a power law stress-strain relation. For the concrete, anisotropic behavior and post-cracking softening model is employed. The formulations lead to a nonlinear boundary value problem which is solved analytically. A key parameter β, defined as the ratio of the volume of corrosion products inside the cracks to the volume of... 

    Effects of alumina nanoparticles concentration on microstructure and corrosion behavior of coatings formed on titanium substrate via PEO process

    , Article Ceramics International ; Volume 42, Issue 7 , May , 2016 , Pages 8789–8797 ; 02728842 (ISSN) Sarbishei, S ; Faghihi Sani, M. A ; Mohammadi, M. R ; Sharif University of Technology
    Elsevier Ltd  2016
    Plasma electrolytic oxidation (PEO) process was employed to create ceramic coatings on titanium substrate by using silicate-based electrolytes containing different concentrations of alumina nanoparticles (0, 3, 6, and 10. g/lit). The effect of alumina nanoparticles concentration on the morphology, chemical and phase composition of the PEO coatings was investigated by scanning electron microscope, energy dispersive spectrometer, and X-ray diffractometer, respectively.The corrosion behavior of samples was studied by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) tests. SEM, EDS, and XRD analyses illustrated that alumina nanoparticles incorporated into the... 

    Mechanical and electrochemical properties of ultrasonic-assisted electroless deposition of Ni-B-TiO2 composite coatings

    , Article Journal of Alloys and Compounds ; Volume 633 , 2015 , Pages 127-136 ; 09258388 (ISSN) Niksefat, V ; Ghorbani, M ; Sharif University of Technology
    Elsevier Ltd  2015
    Nickel-Boron-Titania (Ni-B-TiO2) composite coatings were successfully obtained on mild steel (St-37) by simultaneous electroless deposition. TiO2 particles were dispersed in a suspension by ultrasonic irradiation. The surface morphology, particle size, elemental composition and phase analysis of the coatings were characterized by scanning electron microscopy (SEM), inductively coupled plasma (ICP) and X-ray diffraction (XRD). The hardness and friction coefficient of as- plated and heat treated Ni-B and Ni-B-TiO2 composite coatings were determined by Vickers diamond indentation and indentation scratch tests and compared with Ni-B coatings. As a result, the hardness (1263 HV) of the as-plated... 

    Synergistic inhibition effect of zinc acetylacetonate and benzothiazole in epoxy coating on the corrosion of mild steel

    , Article Journal of Materials Engineering and Performance ; Volume 24, Issue 6 , 2015 , Pages 2464-2472 ; 10599495 (ISSN) Amoozadeh, S. M ; Mahdavian, M ; Sharif University of Technology
    Springer New York LLC  2015
    The corrosion inhibition effect of zinc acetylacetonate (ZAA) and benzothiazole (BTH) mixture was evaluated for mild steel in 3.5% NaCl solution. To this end, ZAA:BTH mixtures ranged from 6:1 to 1:6 mol ratios were examined by weight loss and open circuit potential to obtain optimal mole ratio. The optimal mixture of ZAA:BTH at 1:5 mol ratio showed a significant corrosion inhibition efficiency proved by electrochemical impedance spectroscopy and polarization studies. The addition of the optimal mixture of ZAA:BTH to epoxy coating showed a considerable increase of corrosion protection evaluated by salt spray exposure  

    Evaluation of the corrosion protection properties of an epoxy coating containing sol-gel surface modified nano-zirconia on mild steel

    , Article RSC Advances ; Volume 5, Issue 36 , Mar , 2015 , Pages 28769-28777 ; 20462069 (ISSN) Haddadi, S. A ; Mahdavian, M ; Karimi, E ; Sharif University of Technology
    Royal Society of Chemistry  2015
    In this study, the effect of surface modified nano-zirconia (nano-ZrO2) on the corrosion protection of epoxy coating on mild steel was investigated. An organosilane (trimethoxy methyl silane) was used as a surface modifier to improve the dispersability of the inorganic nanoparticles in the organic coating matrix. Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) were used to characterize the sol-gel surface modified nanoparticles. The dispersability of the modified and unmodified nano-zirconia in an epoxy coating was examined by field emission-scanning electron microscopy (FE-SEM). Electrochemical impedance spectroscopy (EIS) and salt spray were employed to... 

    Estimation of the kinetic parameters of processes at the negative plate of lead-acid batteries by impedance studies

    , Article Journal of Power Sources ; Volume 195, Issue 17 , September , 2010 , Pages 5789-5793 ; 03787753 (ISSN) Rezaei Niya, S. M ; Hejabi, M ; Gobal, F ; Sharif University of Technology
    Impedance characteristics of the negative electrode of lead-acid battery were derived on the basis of fundamental interfacial processes occurring at the electrode. The solution of the governing equations was presented in terms of a simple equivalent circuit consisting of resistive and capacitive loops in which charge transfer and sulfate layer formation and also mass transfer (Warburg) elements are considered. The kinetic parameters were deduced by fitting the theoretically derived impedance to the experimental data. Impedance at various States of Charge (SoC) was also examined  

    Electrochemically Assisted Photocatalytic Oxidation of Methanol on TiO2 Nanotube Arrays

    , Article Journal of Materials Science and Technology ; Volume 26, Issue 6 , June , 2010 , Pages 535-541 ; 10050302 (ISSN) Mohammadpour, R ; Irajizad, A ; Taghavinia, N ; Rahman, M ; Ahadian, M. M ; Sharif University of Technology
    The influence of an externally applied bias on photocatalytic performance of crystallized TiO2/Ti nanotubular electrode formed by anodization in fluoride-based electrolyte were investigated and compared to the behavior of multiporous TiO2 electrode. The photoelectrocatalytic oxidation behavior of methanol over the nanotubular electrode has been studied by measuring photocurrent response, potentiodynamic polarization spectroscopy and using electrochemical impedance spectroscopy (EIS). It was found that the photoelectrocatalytic oxidation and the charge transfer rate constant of reaction on TiO2/Ti nanotubular electrode can significantly be increased by applying electrochemical bias. Moreover,... 

    Inhibitor-loaded conducting polymer capsules for active corrosion protection of coating defects

    , Article Corrosion Science ; Volume 112 , 2016 , Pages 138-149 ; 0010938X (ISSN) Pirhady Tavandashti, N ; Ghorbani, M ; Shojaei, A ; Mol, J. M. C ; Terryn, H ; Baert, K ; Gonzalez Garcia, Y ; Sharif University of Technology
    Elsevier Ltd 
    This work presents the synthesis of nanostructured hollow polyaniline (PANI) capsules and their application for encapsulation of corrosion inhibitor 2-Mercaptobenzothiazole (MBT). The pH-triggered release of MBT from the capsules was evidenced using UV–vis and Surface Enhanced Raman Spectroscopy (SERS). Incorporation of MBT loaded PANI capsules into epoxy ester coating on AA2024-T3 resulted in a protective system with self-healing ability confirmed by Electrochemical Impedance Spectroscopy (EIS) and Scanning Vibrating Electrode Technique (SVET). The results showed that the incorporation of MBT-loaded PANI capsules into the coating has significantly improved its corrosion protection... 

    PH responsive Ce(III) loaded polyaniline nanofibers for self-healing corrosion protection of AA2024-T3

    , Article Progress in Organic Coatings ; Volume 99 , 2016 , Pages 197-209 ; 03009440 (ISSN) Pirhady Tavandashti, N ; Ghorbani, M ; Shojaei, A ; Gonzalez Garcia, Y ; Terryn, H ; Mol, J. M. C ; Sharif University of Technology
    Elsevier  2016
    Cerium nitrate loaded polyaniline (PANI) nanofibers were synthesized in this work via a chemical route. PANI nanofibers act as a host structure for the corrosion inhibitor, forming a Ce(III)-PANI complex. This complex is pH sensitive, and a change of pH can cause breaking of the complex and releasing of Ce(III). The Ce(III) loaded PANI nanofibers were embedded into epoxy ester coating and the self-healing corrosion protection ability was investigated by Scanning Vibrating Electrode Technique (SVET) and Electrochemical Impedance Spectroscopy (EIS). The results showed that by embedding of Ce(III) loaded PANI nanofibers into the coatings a superior corrosion protection and self-healing...