Loading...
Search for: sulfones
0.007 seconds
Total 64 records

    Natural gas hydrate promotion capabilities of toluene sulfonic acid isomers

    , Article Polish Journal of Chemical Technology ; Vol. 16, Issue. 1 , 2014 , pp. 97-102 ; ISSN: 1899-4741 Jarrahian, A ; Heidaryan, E ; Sharif University of Technology
    Abstract
    The purpose of this study was to investigate the natural gas hydrate promotion capabilities of the hydrotrope Toluene Sulfonic Acid (TSA) isomers as an additive. The capabilities of TSA isomers were measured with different concentrations. The optimum additive concentration for hydrate formation was determined for the given pressure, temperature, mixing condition, and cooling time. The natural gas hydrate promotability of para-TSA was found to be 20% and 35% more than meta-TSA and ortho-TSA respectively at the optimum concentration. Beyond the optimum TSA concentration, the hydrate formation declined as the ice formation reduced the overall gas-to-water volume ratio in the hydrates  

    The LiClO4-mediated synthesis of β-(dialkylamino) sulfoxides and β- (dialkylamino) sulfones by addition of α-lithiated salts of sulfoxides and sulfones to aldehydes and (trimethylsilyl)dialkylamines

    , Article European Journal of Organic Chemistry ; Issue 9 , 2000 , Pages 1735-1739 ; 1434193X (ISSN) Naimi Jamal, M. R ; Ipaktschi, J ; Saidi, M. R ; Sharif University of Technology
    Wiley-VCH Verlag  2000
    Abstract
    The LiClO4-mediated one-pot reaction of aldehydes with (trimethylsilyl)dialkyl amines and the lithium salt of sulfoxides or sulfones, affords the corresponding β-(dialkylamino) sulfoxides and β- (dialkylamino) sulfones in high yields. The aminosulfoxidation reaction of aliphatic or aromatic aldehydes lacks diastereoselectivity, but the diastereomeric sulfoxides can be separated by HPLC or column chromatography for further use  

    Extraction of Oxidized Sulfur Compounds of Gas Oil from Oxidation Desulfurization Reactor Products

    , M.Sc. Thesis Sharif University of Technology Heidari, Mahsa (Author) ; Sayf Kordi, Ali Akbar (Supervisor) ; Ghaedian, Maryam (Supervisor)
    Abstract
    It is well known that sulfur removal from petroleum is necessary for both industrial and environmental reasons. Sulfur in petroleum products corrodes parts of internal combustion engines and refineries due to the formation of sulfur oxyacids and causes major air pollution and acid rain due to exhaust from diesel engines and emission of sulfur oxides. Hydrodesulfurization (HDS), biodesulfurization (BDS), extraction by ionic-liquids (ILs), selective adsorption, alkylation desulfurization and oxidative desulfurization (ODS) are some methods, can be effective in removal of sulfur compounds. Among these new processes, ODS appears to be particularly promising and is currently receiving increasing... 

    Synthesis and characterization of novel water-soluble zinc(II) Schiff-base complexes derived from amino acids and salicylaldehyde-5-sulfonates

    , Article Journal of Coordination Chemistry ; Volume 60, Issue 3 , 2007 , Pages 339-346 ; 00958972 (ISSN) Boghaei, D. M ; Gharagozlou, M ; Sharif University of Technology
    2007
    Abstract
    New water-soluble zinc(II) Schiff-base complexes derived from amino acids (glycine, L-phenylalanine, and L-valine) and salicylaldehyde-5-sulfonates (sodium salicylaldehyde-5-sulfonate and sodium 3-methoxy-salicylaldehyde-5- sulfonate) have been synthesized. The complexes were characterized by elemental analysis, IR, electronic, 1H NMR, and 13C NMR spectra. In the IR spectra of the complexes, the large difference between the asymmetric νas(COO) and symmetric νs(COO) carboxylate stretch, Δν(νas(COO)-νs(COO)) of 199-247 cm-1, indicates monodentate coordination of the carboxylate group. Spectral data showed that in these complexes the ligand is a tridentate ONO moiety, coordinating to the metal... 

    Synthesis of Nanoparticles and Application of the Prepared Catalyst for Some Organic Reactions, Efficient Synthesis of New Thiophene Derivatives and Asymmetric Synthesis of Sulfonic Acid Derivatives

    , Ph.D. Dissertation Sharif University of Technology Saeidian, Hamdollah (Author) ; Matloubi Moghaddam, Firouz (Supervisor)
    Abstract
    ZnO nanopowder has been successfully synthesized by a microwave-assisted solution approach using Zn(CH3CO2)2.2H2O and NaOH. The results obtained from XRD, SEM and TEM show that the mean particle size is 30 nm. SEM and TEM micrographs of ZnO nanopowder also reveal that nanoparticles have spherical shape. A convenient one-pot multi-component reaction of aromatic aldehydes, enolizable ketones or β-keto esters and acetonitrile in the presence of acetyl chloride and 10 mol % ZnO nanoparticles for the synthesis of β-acetamido ketones/esters at room temperature is described. Catalytic activity of ZnO nanopowder for o-acylation of alcohol and phenol has also been investigated. On the other hand,... 

    Cooperativity effects of intramolecular OH...O interactions on pK a values of polyolalkyl sulfonic acids in the gas phase and solution: A density functional theory study

    , Article Journal of Physical Organic Chemistry ; Vol. 27, issue. 7 , 2014 , p. 604-612 Najdian, A ; Shakourian-Fard, M ; Fattahi, A ; Sharif University of Technology
    Abstract
    Density functional theory method and B3LYP/6-311++G(d,p) level of theory were used to determine the acidity of alkyl sulfonic acids and polyolalkyl sulfonic acids in the gas and solution (H2O, DMSO, and CH 3CN) phase. Polarized continuum model was applied to calculate pKa values of alkyl sulfonic acids and polyolalkyl sulfonic acids. A comparison between acidity of alkyl sulfonic acids and polyolalkyl sulfonic acids in the gas and solution phase indicates that the acidity strength of polyolalkyl sulfonic acids enhances with the increase of the cooperativity effect of intramolecular hydrogen bonds in polyolalkyl sulfonic acids. Natural bond orbital and quantum theory of atoms in molecules... 

    Production of chlorosulfonated rubber from postconsumer polyethylene and evaluation of produced rubber properties

    , Article Polymer - Plastics Technology and Engineering ; Volume 47, Issue 5 , 2008 , Pages 508-514 ; 03602559 (ISSN) Moradi, A ; Ramazani, S. A. A ; Shahrokhi, M ; Sharif University of Technology
    2008
    Abstract
    In order to convert the postconsumer polyethylene to a valuable product, chlorosulfonation of virgin and highly degraded polyethylene has been carried out in the solution phase under atmospheric pressure. Produced chlorosulfonated polyethylene samples from virgin and degraded HDPE are compounded and cured at different temperatures and their mechanical properties are determined. The results show that degradation of used polyethylene does not have noticeable negative effects on the final mechanical properties of produced chlorosulfonated rubbers. Therefore, it can be concluded that chlorosulfonation can be considered as an effective new method for polyolefin recycling  

    Novel high-performance nanocomposite proton exchange membranes based on poly (ether sulfone)

    , Article Renewable Energy ; Volume 35, Issue 1 , 2010 , Pages 226-231 ; 09601481 (ISSN) Hasani-Sadrabadi, M.M ; Dashtimoghadam, E ; Ghaffarian, S.R ; Hasani Sadrabadi, M.H ; Heidari, M ; Moaddel, H ; Sharif University of Technology
    2010
    Abstract
    In the present research, proton exchange membranes based on partially sulfonated poly (ether sulfone) (S-PES) with various degrees of sulfonation were synthesized. It was found that the increasing of sulfonation degree up to 40% results in the enhancement of water uptake, ion exchange capacity and proton conductivity properties of the prepared membranes to 28.1%, 1.59 meq g -1, and 0.145 S cm -1, respectively. Afterwards, nanocomposite membranes based on S-PES (at the predetermined optimum sulfonation degree) containing various loading weights of organically treated montmorillonite (OMMT) were prepared via the solution intercalation technique. X-ray diffraction patterns revealed the... 

    Extraordinary swelling behavior of poly (AMPS) organogelin solvent/DMSO binary mixed media

    , Article Journal of Applied Polymer Science ; Volume 117, Issue 2 , July , 2010 , Pages 1127-1136 ; 00218995 (ISSN) Zohuriaan Mehr, M. J ; Kabiri, K ; Kheirabadi, M ; Sharif University of Technology
    2010
    Abstract
    The present article deals with super-swelling behavior of crosslinked homopolymer of 2-acrylamido-2-methylpropane sulfonic acid, poly(AMPS), in binary mixtures of dimethyl sulfoxide (DMSO) and various polar solvents including water, mono-, and polyhydric alcohols, and amide solvents such as N-methyl pyrrolidone. Extraordinary phase transition sequences including a new unusual swelling phenomenon, referred to as "overentrant" swelling, was observed for this polymeric organogel in the solvent/DMSO mixtures. The swelling behaviors were preliminarily explained based on the major interactions involved in the solvation process and dielectric constant of the swelling media. It was established that... 

    Thioamides, Quinolinium and Isoquinolinium Salts: Useful Synthons in the Synthesis of Heterocyclic Compounds and Asymmetric Synthesis of Sulfonic acid Derivatives

    , Ph.D. Dissertation Sharif University of Technology Mirjafary, Zohreh (Author) ; Matloubi Moghaddam, Firouz (Supervisor)
    Abstract
    We have reported a new and efficient synthesis of a broad spectrum of heterotetracyclic benzoxazocines via unique tandem 1,3-dinucleophilic addition of different bifunctional nucleophiles to quinolinium and isoquinolinium salts. The reaction generally involves the initial addition of nucleophiles to quinolinium salts to form enamine intermediate which can be trapped by intramolecular O/S-alkylation of nucleophiles. This protocol is a very mild and simple method for construction of eight-membered ring in fused heterocycles in a one-step process. We have also developed an efficient asymmetric synthesis of α,β-disubstituted γ-bisalkoxycarbonyl and α, β- disubstituted γ- phosphono sulfonates via... 

    Preparation of Polyethersulfone Membrane for Separation of Aroma Compounds in Grape Juice

    , M.Sc. Thesis Sharif University of Technology Ghadiri, Sama (Author) ; Roostaazad, Reza (Supervisor) ; Mousavi, Abbas (Co-Advisor)
    Abstract
    Many aroma compounds of fruit juice recovered by thermal processes like evaporation and distillation can lead to undesirable chemical changes and even their loss. Pervaporation is a promising process for the recovery of volatile organic compounds from their aqueous solutions. In the present work, pervaporation recovery of Butyl acetate as a model solution ofgrape juice aroma compoundwas evaluated with polyethersulfone (PES) and ethylvinylacetate (EVA) membranes. PES membrane generally showed better selectivity so that the separation factor at the concentration of 500 ppmand the temperature of 30°C for PES and EVA membranes, respectively, was 230.78 and 156.9. The effect of two operating... 

    Preparation of Membrane Contactor for H2S, CO2 and CH4 Separation

    , M.Sc. Thesis Sharif University of Technology Ashoubi, Farzad (Author) ; Roosta Azad, Reza (Supervisor) ; Moosavi, Abbas (Supervisor)
    Abstract
    Recently separation technology has been developed and engineers are trying to find more rapid and more economic ways in order to reach pure materials. One of the most important needs of human being is natural gas which has some impurities. Acid gases such as carbon dioxide and hydrogen sulfide must be separated from methane. This operation is called gas sweetening. Membrane contactors are equipments recently developed and may be used instead of packed towers for gas sweetening in the future. In this project we designed and made a membrane contacting unit to separate carbon dioxide and hydrogen sulfide from methane. This unit lets you to study the effect of many parameters such as gas and... 

    Surface Modification of Ultrafiltration Membranes to Reduce Fouling in the Dairy Industry

    , M.Sc. Thesis Sharif University of Technology Jabari, Behnam (Author) ; Musavi, Abbas (Supervisor) ; Molaei Dehkordi, Asghar (Co-Supervisor)
    Abstract
    In the dairy industry, for the processing of raw milk, including the isolation of living bacteria and microorganisms from milk to increase the shelf life and improve the taste of milk, or the isolation of casein and whey proteins from milk for pHarmaceutical and medical purposes, as well as the production of low-lactose or lactose-free milk for patients with Digestive problems, use membrane processes, especially ultrafiltration and microfiltration, and the main problem in these methods is the fouling of the polymer membranes used, which results in the loss of flux or the reduction of product quality and system efficiency. With the help of bulk modification and surface modification of the... 

    Synthesis of Novel Bimetallic Nanocomposite of Copper and Silver Based on Metal Organic Frameworks and Investigation of Its Application as Catalyst in Sulfonation Reaction

    , M.Sc. Thesis Sharif University of Technology Yaghoubnejad Pazoki, Parisa (Author) ; Matloubi Moghaddam, Firouz (Supervisor)
    Abstract
    In recent years, bimetallic metal-organic frameworks have attracted the great attention of researchers due to their dual properties and synergistic effects. In this research and inspired by green chemistry, the synthesis of a magnetic nanocomposite of the defective green metal-organic framework was implemented, which carries metallic silver nanoparticles (Ag NPs@Cu-MOF). Then, the sulfonated compounds were synthesized with the prepared nanocomposite because of the importance and widespread medicinal use of sulfur-containing compounds especially sulfonated compounds, and the difficulty of their preparation methods. It is noteworthy to mention that the sulfonation reaction was done by... 

    One-pot reductive amination of aldehydes by the dihydropyridine in water

    , Article Scientia Iranica ; Volume 19, Issue 6 , December , 2012 , Pages 1591-1593 ; 10263098 (ISSN) Ghafuri, H ; Hashemi, M. M ; Sharif University of Technology
    2012
    Abstract
    An efficient, highly chemoselective and simple synthesis of secondary amines via reductive amination of aldehydes, aromatic amines and inexpensive and easily accessible Diethyl 2,6-dimethyl-1,4-dihydro-3,5-pyridinedicarboxylate (DHP) in the presence of catalytic amounts of p-toluenesulfonic acid (PTSA) in water in good to excellent yields is reported  

    Efficient diastereo- and enantioselective synthesis of α,β-disubstituted γ-phosphono sulfonates

    , Article Tetrahedron Asymmetry ; Volume 20, Issue 21 , 2009 , Pages 2429-2431 ; 09574166 (ISSN) Enders, D ; Mirjafary, Z ; Saeidian, H
    2009
    Abstract
    The first asymmetric synthesis of α,β-disubstituted γ-phosphono sulfonates is reported. The key step is the Michael addition of a lithiated enantiopure sulfonate bearing an inexpensive chiral sugar auxiliary to α,β-unsaturated phosphonates in good diastereoselectivities. After chromatographic purification, the cleavage of the chiral sugar auxiliary proceeds without any epimerization or racemization to form the corresponding isopropyl sulfonate in very good overall yield (75%) and excellent diastereomeric and enantiomeric excess (de, ee ≥ 95%). © 2009 Elsevier Ltd. All rights reserved  

    Quantitative determination of linear alkylbenzene sulfonate (LAS) concentration and simultaneous power generation in a microbial fuel cell-based biosensor

    , Article Journal of Cleaner Production ; Volume 294 , 2021 ; 09596526 (ISSN) Askari, A ; Vahabzadeh, F ; Mardanpour, M. M ; Sharif University of Technology
    Elsevier Ltd  2021
    Abstract
    Linear alkylbenzene sulfonate (LAS), one of the most widely used synthetic surfactants in laundry detergent industry, is considered a hazardous contaminant in wastewater. In the present study, a microbial fuel cell (MFC) based biosensor is developed to quantitively determine the LAS concentration in wastewater. To do so, the developed MFC is fed with LAS concentration of 60 mg l−1. Finally, a sustained biofilm is formed after almost 34 days and the highest open circuit potential of 425 mV is recorded. The maximum power and current densities of 75 mW m−3 and 663 mA m−3 are obtained, respectively; and the internal resistance of the MFC-based biosensor is calculated to be about 1 kΩ. After 98... 

    Simultaneous/sequential alkaline-surfactant-polymer flooding in fractured/non-fractured carbonate reservoirs

    , Article Canadian Journal of Chemical Engineering ; Vol. 92, issue. 5 , May , 2014 , p. 918-927 ; ISSN: 00084034 Sedaghat, M. H ; Ghazanfari, M. H ; Masihi, M ; Sharif University of Technology
    Abstract
    Alkaline-Surfactant-Polymer flooding is one of the most novel chemical enhanced oil recovery methods in the petroleum industry. This method has attracted interest due to its remarkable advantages. In this work, a series of ASP floods are conducted on fractured/non-fractured carbonate rocks. The performance of the tests was investigated by various ASP floods consisting of five types of polymers, two surfactants and one common alkaline. ASP was flooded simultaneously and sequentially in four defined scenarios after water flooding. The results showed that although using hydrolysed polymers increases the recovery factor in the fractured medium, sulfonated polymers increase oil recovery even more... 

    Super alcohol-absorbent gels of sulfonic acid-contained poly(acrylic acid)

    , Article Journal of Polymer Research ; Volume 18, Issue 3 , 2011 , Pages 449-458 ; 10229760 (ISSN) Kabiri, K ; Lashani, S ; Zohuriaan Mehr, M. J ; Kheirabadi, M ; Sharif University of Technology
    2011
    Abstract
    Alcohol-specific superabsorbing gels (superalcogels) based on non-neutralized acrylic acid (AA, 60-94 mol%) and 2-acrylamido-2-methylpropane sulfonic acid (AMPS) were prepared via solution polymerization in water. Polyethylene glycol dimethacrylate and potassium persulfate were used as crosslinker and initiator, respectively. Characterization of samples was performed using FTIR, 1H-NMR and thermomechanical analyses. Glass transition temperature and modulus of dried samples were found to be directly changed with their AA content. The gels exhibited enormous ability for absorbing and retaining a variety of mono- and poly-hydric alcohols. For example, in lieu of one gram of a typical sample... 

    Fabrication of MEA based on sulfonic acid functionalized carbon supported platinum nanoparticles for oxygen reduction reaction in PEMFCs

    , Article RSC Advances ; 2015 , Pages 85775-85784 ; 20462069 (ISSN) Gharibi, H ; Yasi, F ; Kazemeini, M ; Heydari, A ; Golmohammadi, F ; Sharif University of Technology
    Royal Society of Chemistry  2015
    Abstract
    The Nafion ionomer affects the efficiency of the platinum (Pt) catalyst by blocking the active sites thereby restricting the gas permeability of the catalyst layer; but, there is a limitation in the quantity of Nafion ionomer that needs to be added without affecting the cell performance. Sulfonation of carbon-supported catalysts as mixed electronic and protonic conductors has been reported to be an efficient way to increase the triple-phase boundaries. In order to improve the utilization and activity of cathodic catalysts in the oxygen reduction reaction (ORR), Pt nanoparticles were loaded on a mixture of Vulcan XC-72R and MWCNTs, which were functionalized in a mixture of 96% sulfuric acid...