Search for: sulfide
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    Atmospheric corrosion evaluation of silver coating using simulating technique test

    , Article European Corrosion Conference: Long Term Prediction and Modelling of Corrosion, EUROCORR 2004, Nice, 12 September 2004 through 16 September 2004 ; 2004 Nasirpouri, F ; Afshar, A ; Sharif University of Technology
    A standard simulating technique test was investigated to assess the atmospheric corrosion behavior of silver coating. The rates of formation of corrosion products were measured in the simulating atmospheres of 100% humidity containing SO 2,H 2S and a complex atmosphere consist of SO 2,H 2S and NO 2 gases ,based on the mass increase method. The concentrations of corrosive gases were chosen according to real world conditions. XRD, SEM and EDS were used to examine the morphology and to determine the composition of the corrosion products under different experimental conditions. Results revealed the formation of Ag 2SO 4 and Ag 2S on the silver coating surfaces in the SO 2 and H 2S containing... 

    H2S Gas Sensing Characterization of Nano-Structured SnO2-CuO Multilayer Sensor

    , M.Sc. Thesis Sharif University of Technology Salehi, Farnaz (Author) ; Ghorbani, Mohammad (Co-Advisor)
    Hydrogen sulfide, H2S, is a toxic gas and has detrimental effects on human health and the oil and gas industry. Therefore, its identification is very important. According to the devastating effects of this gas, then, the general mechanisms have been studied for gas detection. In addition, by highlighting the benefits of the multilayer nanostructure electrochemical sensors, an applicable and efficient method for the industrial production of these sensors has been investigated. In this regard, the sol-gel method is used to prepare the SnO2-CuO multilayer thin film and the advantages of this method was compared to PVD method. Also sensor properties of both deposition methods have been... 

    Synthesis, Characterization and Catalytic Activity of Supported Vanadium Schiff Base Complex as a Magnetically Recoverable Nanocatalyst in Epoxidation of Alkenes and Oxidation Of Sulfides

    , M.Sc. Thesis Sharif University of Technology Bahjati, Mohammad (Author) ; Bagherzadeh, Mojtaba (Supervisor)
    In this project, a new magnetically recoverable nanocatalyst was developed by immobilizing of vanadyl acetylacetonate, [VO(acac)2], onto surface of silica coated magnetite nanoparticlest that modified by reaction between 3-aminopropylthriethoxy silane and 5-bromosalicylaldehyde. In the first step, magnetite cores were synthesized by co-precipitation method and coated by tetraethyl orthosilicate (TEOS) and modified by 3-aminopropyltriethoxy silane to provide a precursor for Schiff base condensation reaction. In the next step, amino-functionalized silica coated magnetite nanoparticles were reacted by 5-bromosalicylaldehyde to formation a Schiff base moiety onto surface of magnetite coated... 

    Enhancing bioleaching and iron oxidation efficiency of native strain of acidithiobacillus ferrooxidans, by optimizing the ambient growth conditions

    , Article Pollution Research ; Volume 28, Issue 3 , 2009 , Pages 329-336 ; 02578050 (ISSN) Arabian, D ; Nemati, F ; Roostaazad, R ; Shitole, M. G ; Gade, W. N ; Sharif University of Technology
    In this study, we have investigated the bioleaching potential of a native strain of Acidithiobacillus ferrooxidans isolated from zinc and lead sulfide mines under varied ambient conditions of growth and substrate consumption. In the process of standardizing growth conditions to improve iron oxidation, bioleaching of zinc and lead is also found to be enhanced. The effects of pH, temperature, initial inoculum, Fe2+ and ammonium sulphate concentration on growth and bio-oxidation efficiency of the bacteria have been evaluated. The results indicate that the optimum pH required for the growth of the bacterium is 1.8; however, the same for maximum efficiency is 1.5. It is also found that pH has a... 

    Oxido-peroxido W(VI)-histidine–MgAl-layered double hydroxide composite as an efficient catalyst in sulfide oxidation

    , Article Applied Organometallic Chemistry ; Volume 32, Issue 6 , 2018 ; 02682605 (ISSN) Nikkhoo, M ; Amini, M ; Morteza, S ; Farnia, F ; Bayrami, A ; Bagherzadeh, M ; Gautam, S ; Chae, K. H ; Sharif University of Technology
    John Wiley and Sons Ltd  2018
    Oxido-peroxido W(VI)-histidine–MgAl-layered double hydroxide composite was prepared by using MgAl-layered double hydroxide as a host and oxido-peroxido W(VI)-histidine complex as a guest. The composite was characterized by XRD, IR, EDX,SEM and TEM techniques. This composite is tested for catalytic selective sulfoxidation reactions using hydrogen peroxide as oxidant showing good to moderate conversion along with high selectivity. Copyright © 2018 John Wiley & Sons, Ltd  

    Synthesis and Study of Catalytic Reactivity Oxo Vanadium (IV)& (V) Complexes with N,N'-Ethylenebis(Salicylimine)Ligand in Oxidation of Sulfides and Epioxidation of Olfins by Urea Hydrogen Peroxide (UHP) and Tert-Butyl Hydroperoxide (TBHP)

    , M.Sc. Thesis Sharif University of Technology Nadiri, Siheila (Author) ; Bagherzadeh, Mojtaba (Supervisor)
    The selective oxidation of sulfides to sulfoxides is an important method in organic synthesis because sulfoxides are useful synthetic intermediates for the construction of various chemically and biologically significant molecules. To date, the most important method of preparation involves the oxidation of sulfides. Various oxidizing agents are used for this purpose. Oxovanadium(IV)(Salen) and oxovanadium(V)(Salen)Cl were synthesised and screened in the vanadium-catalysed oxidation of sulfides to solfuxides with urea hydrogen peroxide(UHP) as terminal oxidant. Both complexes showed good activity and selectivity trough the catalytic reaction.characterized by elemental analyses, IR, 1H and 13C... 

    Synthesis of some Cu(II) - 2-(2'-hydroxyphenyl)-2-oxazoline and Mn(III) - 2-(2',4'-dihydroxyphenyl)-2-oxazoline Complexes and their Application as Catalysts in Sulfides and Alcohols Oxidations

    , M.Sc. Thesis Sharif University of Technology tahay moghadam, Pooya (Author) ; Bagherzadeh, Mojtaba (Supervisor)
    In this project two manganese(III) complexes with 2-(2',4'-dihydroxyphenyl)-2-oxazoline ligand, [Mn(4-OHphox)3], [Mn(4-OHphox)2(CH3OH)2]ClO4 and a copper(II) complex with 2-(2'-hydroxy)-2-oxazoline ligand have been synthesized. The complexes and the ligands were characterized by elemental analysis (CHN), FT-IR and 1HNMR spectroscopies. Oxidation of sulfides catalyzed by these complexes using urea-hydrogen peroxide (UHP) as oxidant within short reaction times (5 min) was investigated. The results showed that catalytic efficiency of [Mn(4-OHphox)3] complex was better than other complexes. Optimization of the catalyst system presented a high selectivity of sulfoxide (90-100%) in a few time (5... 

    Synthesis and Catalytic Activity of Mo(VI) Oxo-peroxo Complex in Selective Oxidation of Sulfides to Sulfoxides and Alkenes to Epoxides

    , M.Sc. Thesis Sharif University of Technology Atabaki, Behnam (Author) ; Bagherzadeh, Mojtaba (Supervisor) ; Jamali, Sirous (Co-Advisor)
    Considerable efforts have been directed in recent years towards the transition metal complex catalyzed oxidation of organic compounds. Among these, oxidation of sulfides to sulfoxides and alkenes to epoxides have specially been attended a lot, since sulfoxides and epoxides are important intermediates in organic synthesis. In this study [MoO(O2)(oxazine)2] complex has been synthesized and characterized by FT-IR and 1HNMR. This complex was found to be an efficient, selective catalyst for the oxidation of various sulfides to sulfoxides with urea hydrogen peroxide (UHP) in excellent yields (100% for dioctylsulfide) and short reaction times (20 min) at room temperature. Also this new efficient... 

    Studying and Synthesize of H2S Gas Sensors Based on Modified WO3 Nanostructure Thin Films

    , M.Sc. Thesis Sharif University of Technology Kashani, Shima (Author) ; Iraji zad, Aazam (Supervisor) ; Rahimi, Fereshte (Co-Advisor)
    H2S is a toxic gas used in chemical laboratories and industries. H2S is also liberated in nature due to biological processes and also from mines and petroleum fields. At some threshold level, exposure to concentrations over 10 ppm can result in headaches, irritability, dizziness and in some case leads to death. So that introducing sensors which sense H2S at ppm level with the low response time is so essential. The present work emphasizes on H2S resistance-sensing properties of pure and Pd doped WO3 films prepared by Arc discharge method. XRD, SEM, EDAX and XPS were applied to analyze crystal structure, morphology and chemical composition of the films. The analyzes results showed that films... 

    Synthesis, Characterization and Catalytic Activity of Vanadium(v) Complex with Tridentate Schiff Base Ligand N´-[1-(2-Hydroxynaphthyl) Methylene]-2-Hydroxy Benzohydrazide

    , M.Sc. Thesis Sharif University of Technology Mahmood Khanlu, Reza (Author) ; Bagherzadeh, Mojtaba (Supervisor) ; Mohammadi Boghaei, Davar (Supervisor)
    In this project a new dioxovanadium (V) complex of Schiff base ligand N`-[1-(2-hydroxynaphthyl)methylene]-2-hydroxy benzohydrazide was synthesized and fully characterized. This complex is a pentacoordinate one in which the dioxo groups are in cis form. For synthesis of this complex, first, the intermediate compound 2-hydroxy benzohydrazide was synthesized from hydrazine and methyl salicylate and condensed with 2-hydroxynaphthaldehyde to give the Schiff base ligand (H2NBD). Then from reaction of ligand and ammonium vanadate in DMF in 65 ̊C, the NH4[VO2(NBD)] was prepared. This complex was fully characterized by UV, NMR and IR spectroscopies and it’s application as catalyst in sulfoxidation... 

    Oxidation of sulfides with urea-hydrogen peroxide catalyzed by iron-salen complexes

    , Article Journal of Sulfur Chemistry ; Volume 32, Issue 4 , 2011 , Pages 335-343 ; 17415993 (ISSN) Bagherzadeh, M ; Zare, M ; Sharif University of Technology
    The oxidation of sulfides to sulfoxides with hydrogen peroxide in good yield and high selectivity has been catalyzed very effectively by a series of Schiff base salen-type iron complexes in a monophasic medium (CH 2Cl2/CH3OH) at ambient temperature. The results of the present study show that the reaction rate strongly depends on both catalyst steric effects and steric and electronic properties of sulfides. In the system, the electronic spectral studies are applied to explain the formation of a reactive (salen) Fe=O intermediate  

    Removal of hydrogen sulfide from methane using commercial polyphenylene oxide and Cardo-type polyimide hollow fiber membranes

    , Article Korean Journal of Chemical Engineering ; Volume 28, Issue 3 , March , 2011 , Pages 902-913 ; 02561115 (ISSN) Chenar, M. P ; Savoji, H ; Soltanieh, M ; Matsuura, T ; Tabe, S ; Sharif University of Technology
    The performance of commercially available poly (2,6-dimethyl-1,4-phenylene oxide) (PPO) and Cardotype polyimide (PI) hollow fiber membranes was investigated in removing hydrogen sulfide from methane in a series of bench-scale experiments. It was observed that in the concentration range of hydrogen sulfide in methane from 101 to 401 ppm, the methane permeability decreased in the presence of hydrogen sulfide for Cardo-type polyimide hollow fiber membranes, whereas the PPO membrane performance was not affected. The separation coefficients of hydrogen sulfide/methane were 6 and 4 for PI and PPO membranes, respectively. Effects of temperature on the performance of PI and PPO membranes were... 

    Mathematical modeling and simulation of hollow fiber membranes for separation of gas mixtures: Case study with separation of H 2S/CH 4 by polyphenylene oxide (PPO) hollow fiber module

    , Article 19th International Congress of Chemical and Process Engineering, CHISA 2010 and 7th European Congress of Chemical Engineering, ECCE-7, Prague, 28 August 2010 through 1 September 2010 ; 2010 Niknejad, S. M. S ; Savoji, H ; Soltanieh, M ; Sharif University of Technology
    A mathematical model has been developed that is based the dual sorption in the dense layer and pore flow in the porous layer. In the porous layer a resistance model is applied where four mechanisms, i.e., Knudsen, Viscous, Slip, and Surface flows, are superimposed. Steady-state, constant pressure along the membrane and constant physical properties are assumed. Its application to the separation of H 2S/CH 4 gas mixtures as a sour gas in natural gas sweetening by using a PPO hollow fiber module is put forward. The Quasi Newton method is used to determine the parameters of membrane transport model for the case of H 2S/CH 4 separation. The H 2S and CH 4 permeances increased by increasing the... 

    Synthesis and characterization of two binuclear nickel(II) complexes of thiophenol-based "end-off" compartmental ligands and their application as catalysts for selective oxidation of sulfides

    , Article Journal of Coordination Chemistry ; Volume 69, Issue 1 , 2016 , Pages 103-111 ; 00958972 (ISSN) Khadir, N ; Amini, M ; Assoud, A ; Bagherzadeh, M ; Boghaei, D. M ; Sharif University of Technology
    Taylor and Francis Ltd  2016
    Reaction of the binucleating S-protected ligand precursors 2-(N,N-dimethylthiocarbamato)-5-methylisophthalaldehyde di-2′-hydroxy anil (I) and 2-(N,N-dimethylthiocarbamato)-5-methylisophthalaldehyde di-2′-hydroxy 5′-methyl anil (II) with nickel(II) acetate tetrahydrate in the presence of pyrazole afforded the binuclear nickel(II) complexes [LINi2(pz)] (1) and [LIINi2(pz)] (2), respectively. The complexes have been characterized by routine physicochemical studies as well as by X-ray single crystal structure analysis. In both complexes, Ni(II) ions are doubly bridged by the thiophenolic sulfur of the pentadentate Schiff base ligand and a pyrazolate group. Efficient protocols for the oxidation... 

    Synthesis, X-ray structure and study of a mixed ligand iron(III) complex with tridentate Schiff base as a homogeneous catalyst in the efficient oxidation of sulfides

    , Article Inorganic Chemistry Communications ; Volume 12, Issue 6 , 2009 , Pages 476-480 ; 13877003 (ISSN) Bagherzadeh, M ; Tahsini, L ; Latifi, R ; Amani, V ; Ellern, A ; Keith Woo, L ; Sharif University of Technology
    A mononuclear mixed ligand complex of iron, [FeIII(N-OPh-sal)(acac)EtOH], where Hacac and N-HOPh-Hsal denote acetylacetone and N-hydroxyphenyl-salicylideneamine, respectively, has been synthesized and characterized by elemental analysis, spectral studies and X-ray crystallography. The catalytic system containing this complex and urea hydrogen peroxide as oxidizing agent was used to selectively oxidize a range of sulfides to the corresponding sulfoxides in good yields under mild conditions. The electronic spectra of the catalytic system were applied to explore reactivity and stability of the catalyst during sulfide oxidation reactions and to examine the nature of active species, as well. ©... 

    Wide color-varying visualization of sulfide with a dual emissive ratiometric fluorescence assay using carbon dots and gold nanoclusters

    , Article Microchemical Journal ; Volume 157 , September , 2020 Farahmand Nejad, M. A ; Bigdeli, A ; Hormozi Nezhad, M. R ; Sharif University of Technology
    Elsevier Inc  2020
    Development of visual detection methods regarding water pollutants can effectively facilitate water resource monitoring programs. A wide color-varying ratiometric approach has been developed for sensitive determination of sulfide by mixing orange emissive glutathione stabilized gold nanoclusters (AuNCs) and blue emissive urea stabilized carbon dots (CDs) in an appropriate ratio. Under a single excitation wavelength of 365 nm, the ratiometric fluorescence (RF) probe exhibited two distinct emission bands at 452 and 607 nm corresponding to CDs and AuNCs, respectively. Owing to the high affinity of sulfide ions to AuNCs in alkaline medium, the fluorescence (FL) of AuNCs was turned-off while the... 

    A novel binuclear iron(III)-salicylaldazine complex; synthesis, X-ray structure and catalytic activity in sulfide oxidation

    , Article Polyhedron ; Volume 183 , June , 2020 Mesbahi, E ; Bagherzadeh, M ; Amini, M ; Akbari, A ; Ellern, A ; Woo, L. K ; Sharif University of Technology
    Elsevier Ltd  2020
    A novel binuclear iron(III)-salicylaldazine complex has been synthesized and characterized by various techniques such as IR and UV–Vis spectroscopy and X-ray crystallography. The catalytic oxidation of sulfides in the presence of the aforementioned complex was explored at room temperature using urea hydrogen peroxide (UHP) as an oxidant. Effects of different reaction conditions consisting catalyst and oxidant amount, solvent effect and reaction time on the catalytic activity and selectivity in the reaction of methylphenylsulfide oxidation has been surveyed. Perfect selectivity toward sulfoxide was achieved after 15 min in CH3CN by choice of a properly optimized reaction condition. © 2020... 

    Hybrid supercapacitors constructed from double-shelled cobalt-zinc sulfide/copper oxide nanoarrays and ferrous sulfide/graphene oxide nanostructures

    , Article Journal of Colloid and Interface Science ; 2020 Shahi, M ; Hekmat, F ; Shahrokhian, S ; Sharif University of Technology
    Academic Press Inc  2020
    Evolution of renewable energies in the era of the modernized world has been strongly tied up to the incessant development of high-performance energy storage systems benefiting from both high energy and power densities. In the present work, binder-free positive electrodes are fabricated via a facile electrochemical deposition route in which copper oxide nanorods (CuO NRs) directly grown onto the copper foam (CF) are decorated with bimetallic cobalt-zinc sulfide nanoarrays (Co-Zn-S NAs). The fabricated Co-Zn-S@CuO-CFs represent promising specific capacity of 317.03 C.g−1 at 1.76 A.g−1, along with superior cyclic stability (113% retention after 4500 cycles). Negative electrodes were further... 

    Sulfide removal by natural mix of chemotrophic sulfide oxidizing bacteria in anaerobic conditions

    , Article CHISA 2006 - 17th International Congress of Chemical and Process Engineering, Prague, 27 August 2006 through 31 August 2006 ; 2006 ; 8086059456 (ISBN); 9788086059457 (ISBN) Amirfakhri, J ; Vossoughi, M ; Soltanieh, M ; Rizi, Z. T ; Sharif University of Technology
    Most sulfide oxidizing bioreactors are based on pure cultures or artificial mixes of microorganisms with strict requirements for growth, which make the system unstable and do not guarantee their long term performance. The ultimate goal of this study is to develop a natural mix of chemotrophic bacteria that may be applied anaerobically for the treatment of sour gas. Activated sludge from local municipal wastewater treatment plant that was maintained in endogenous anaerobic conditions for one year was used in this study. Total suspended solids (TSS) and volatile suspended solids (VSS) of the sludge was 22 gl-1 and 14.3 gl-1, respectively. A glass culture vessel had a volume of 0.65 L was used... 

    LiClO4 • 3H2O promoted highly regioselective ring-opening of epoxides with thiols under neutral conditions

    , Article Catalysis Communications ; Volume 7, Issue 4 , 2006 , Pages 224-227 ; 15667367 (ISSN) Azizi, N ; Saidi, M. R ; Sharif University of Technology
    A simple, rapid, atom economy and highly efficient procedure has been developed for thiolysis of epoxides by aromatic and aliphatic thiols under solvent-free conditions. A high regioselectivity in favor of nucleophilic attack at the benzylic carbon atom of aromatic epoxides, such as styrene oxide, is observed. However, aliphatic unsymmetrical alkenyl oxides undergo selective nucleophilic attack at the sterically less hindered carbon atom. A variety of β-hydroxy sulfides were obtained in short reaction time and excellent yields with nearly complete regioselectivity. © 2005 Elsevier B.V. All rights reserved