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    The application of Shannon's measure of information for a complex chemical system

    , Article Journal of Physical Chemistry B ; Volume 110, Issue 25 , 2006 , Pages 12815-12819 ; 15206106 (ISSN) Safinejad, F ; Shafiee, A ; Asghari Khiavi, M ; Sharif University of Technology
    American Chemical Society  2006
    Information theory and, specifically, Shannon's measure of information is used to compare the interaction parameters (β) in regular solution theory (RST) and Ingram's model for the mixture of cetyltrimethylammonium bromide (CTAB) and Triton X-100 (TX100). Results show that β values from regular solution theory are more accurate than those of Ingram's model. Additionally, the procedure applied in this paper for the calculation of uncertainties in the continuous case, prevents difficulties concerning differential entropy. © 2006 American Chemical Society  

    Mesoporous silica-functionalized dual Brønsted acidic ionic liquid as an efficient catalyst for thioacetalization of carbonyl compounds in water

    , Article Catalysis Communications ; Volume 41 , 2013 , Pages 96-100 ; 15667367 (ISSN) Vafaeezadeh, M ; Dizicheh, Z. B ; Hashemi, M. M ; Sharif University of Technology
    A novel silica-functionalized dual Brønsted acidic ionic liquid (ionic liquid with two Brønsted acidic species) has been reported as a highly efficient catalyst for thioacetalization of carbonyl compounds. The reaction was efficiently performed in water as an environmentally benign solvent with good to high yields. Thermal gravimetric analysis showed that the catalyst is stable at least up to 350 C. Furthermore, the catalyst can be recycled and reused for six runs of reaction without appreciable loss of activity. The structure of the catalyst is modelized to gain more realistic structural insight about the functionalized ionic liquid  

    Pd(OAc)2 without added ligand as an active catalyst for Mizoroki-Heck reaction in aqueous media

    , Article RSC Advances ; Volume 2, Issue 32 , 2012 , Pages 12091-12095 ; 20462069 (ISSN) Amini, M ; Bagherzadeh, M ; Moradi Shoeili, Z ; Boghaei, D. M ; Sharif University of Technology
    Conditions for an efficient ligand-free Heck C-C coupling reaction of aryl iodides and bromides with terminal olefins under aerobic conditions have been developed. Critical to the success of this new protocol is the use of palladium acetate as an extremely active catalyst for the Heck reaction in water and aqueous media. Both the base and the solvent were found to have a fundamental influence on the efficiency of the reaction, with K2CO3 and a mixture of (2:1) H2O/DMSO being the optimal base and solvent, respectively  

    A heterogeneous strong basic nanocrystalline copper(II) oxide catalyst for efficient synthesis of 4-keto-4,5,6,7-tetrahydrobenzofurans

    , Article Catalysis Communications ; Volume 10, Issue 10 , 2009 , Pages 1423-1426 ; 15667367 (ISSN) Ahmadi, S. J ; Sadjadi, S ; Hosseinpour, M ; Outokesh, M ; Hekmatshoar, R ; Sharif University of Technology
    An efficient synthesis of tetrahydrobenzofurans is carried out in one pot through the reaction of 1,3-diketone and phenacyl bromides compound using a heterogeneous basic nano particles copper oxide catalyst. The protocol offers advantages in terms of higher yields, short reaction times, and mild reaction conditions, with reusability of the catalyst. © 2009 Elsevier B.V. All rights reserved  

    Reducing ion migration in methylammonium lead tri-bromide single crystal via lead sulfate passivation

    , Article Journal of Applied Physics ; Volume 127, Issue 18 , April , 2020 Mahapatra, A ; Parikh, N ; Kumari, H ; Pandey, M. K ; Kumar, M ; Prochowicz, D ; Kalam, A ; Tavakoli, M. M ; Yadav, P ; Sharif University of Technology
    American Institute of Physics Inc  2020
    Surface passivation of organic-inorganic halide perovskites (OIHPs) is a crucial step to annihilate the surface defects and to control the deteriorated ion migration phenomenon. Here, we study the role of lead sulfate (PbSO4) as an effective passivator in OIHP single crystals (SCs). Using impedance spectroscopy, we evaluate the ion migration and electrical properties of lead sulfate-passivated methylammonium lead tri-bromide (MAPbBr3) SCs. We found that the low-frequency impedance response that is assigned to the ionic motion in the MAPbBr3 SC is strongly affected by the inorganic PbSO4 surface treatment. The activation energy corresponding to the ion migration of MAPbBr3 SC is increased... 

    Size-controlled synthesis of superparamagnetic iron oxide nanoparticles and their surface coating by gold for biomedical applications

    , Article Journal of Magnetism and Magnetic Materials ; Volume 324, Issue 23 , November , 2012 , Pages 3997-4005 ; 03048853 (ISSN) Maleki, H ; Simchi, A ; Imani, M ; Costa, B. F. O ; Sharif University of Technology
    The size mono-dispersity, saturation magnetization, and surface chemistry of magnetic nanoparticles (NPs) are recognized as critical factors for efficient biomedical applications. Here, we performed modified water-in-oil inverse nano-emulsion procedure for preparation of stable colloidal superparamagnetic iron oxide NPs (SPIONs) with high saturation magnetization. To achieve mono-dispersed SPIONs, optimization process was probed on several important factors including molar ratio of iron salts [Fe 3 and Fe 2], the concentration of ammonium hydroxide as reducing agent, and molar ratio of water to surfactant. The biocompatibility of the obtained NPs, at various concentrations, was evaluated via... 

    Polypyrrole nanowires network for convenient and highly efficient microextraction in packed syringe

    , Article Analytical Methods ; Volume 3, Issue 11 , 2011 , Pages 2630-2636 ; 17599660 (ISSN) Bagheri, H ; Ayazi, Z ; Sharif University of Technology
    A novel method based on microextraction in packed syringe (MEPS), as a sample preparation technique in combination with gas chromatography-mass spectrometry (GC-MS) was developed using a polypyrrole (PPy) nanowires network as the extracting medium. The PPy nanowires network was prepared using a soft template technique and its characterization was studied by scanning electron microscopy (SEM). The use of micelles in this methodology has an important role in the shape of the growing polymer. The pyrrole monomer was introduced into cetyltrimethylammonium bromide (CTAB) micelles and this has led to the formation of nanowires with diameters ranging from 30 to 60 nm. The bulk PPy prepared without... 

    Numerical modeling of incline plate LiBr absorber

    , Article Heat and Mass Transfer/Waerme- und Stoffuebertragung ; Volume 47, Issue 3 , November , 2011 , Pages 259-267 ; 09477411 (ISSN) Karami, S ; Farhanieh, B ; Sharif University of Technology
    Among major components of LiBr-H 2O absorption chillers is the absorber, which has a direct effect on the chillier size and whose characteristics have significant effects on the overall efficiency of absorption machines. In this article, heat and mass transfer process in absorption of refrigerant vapor into a lithium bromide solution of water-cooled incline plate absorber in the Reynolds number range of 5

    Polyrotaxane capped quantum dots as new candidates for cancer diagnosis and therapy

    , Article Journal of Nanostructured Polymers and Nanocomposites ; Volume 7, Issue 1 , 2011 , Pages 18-31 ; 17904439 (ISSN) Sarabi, R. S ; Sadeghi, E ; Hosseinkhani, H ; Mahmoudi, M ; Kalantari, M ; Adeli, M ; Sharif University of Technology
    Molecular self-assembly of cadmium selenide quantum dots-end-capped polyrotaxane hybrid nanostructures (PRCdSe QDs) was led to a new type of core-shell hybrid nanomaterials consisting of cadmium selenide quantum dot (CdSe QDs) core and polyrotaxane shell (PR@QDs). Structure of PR@QDs was characterized using various techniques. It has been observed that the size of PR@QDs was between 20-25 nm in which diameter of core and thickness of shell were between 15-20 and 2-3 nm, respectively. Short-term in vitro cytotoxicity tests, using MTT (3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, were conducted on mouse tissue connective fibroblast adhesive cell line (L929) in order to... 

    Synthesis, structural characterization and alcohol oxidation activity of a new mononuclear manganese(II) complex

    , Article Transition Metal Chemistry ; Volume 35, Issue 3 , 2010 , Pages 297-303 ; 03404285 (ISSN) Najafpour, M. M ; Amini, M ; Bagherzadeh, M ; Boghaei, D. M ; McKee, V ; Sharif University of Technology
    A manganese(II) complex of 2,4,6-tris(2-pyridyl)-1,3,5-triazine (tptz) has been synthesized and characterized by single-crystal X-ray diffraction, elemental analyses, IR, and UV-Vis spectroscopic techniques. Oxidation of alcohols to their corresponding aldehydes and ketones was conducted by this catalyst using oxone (2KHSO5KH-SO4K2SO4) as an oxidant under biphasic reaction conditions (CH2Cl2/H 2O) and tetra-n-butylammonium bromide as phase transfer agent under air at room temperature. Easy preparation, mild reaction conditions, high yields of the products, short reaction times, no further oxidation to the corresponding carboxylic acids, high selectivity and inexpensive reagents make this... 

    Gold-Decorated 3D 2,6-diaminopyridine network: a robust catalyst for the bromination of aromatic compounds

    , Article Industrial and Engineering Chemistry Research ; Volume 57, Issue 37 , 2018 , Pages 12314-12322 ; 08885885 (ISSN) Pourjavadi, A ; Keshavarzi, N ; Hosseini, S. H ; Matloubi Moghaddam, F ; Sharif University of Technology
    American Chemical Society  2018
    This article reports the synthesis of a magnetic heterogeneous catalyst through the decoration of gold ions onto the cross-linked polymeric nanocomposite from 2,6-diaminopyridine. The activity of the resulting catalyst was then evaluated in the bromination of aromatic compounds. The nitrogen rich support showed a high affinity to gold ions, and the measured content of Au was 0.76 mmol g-1. The structure of the catalyst was fully characterized by using Fourier-transform infrared spectroscopy, thermogravimetric analysis, atomic absorption spectroscopy, transmission electron microscopy, scanning electron microscope, energy-dispersive X-ray spectroscopy, Brunauer-Emmett-Teller surface area... 

    Fabrication of novel Fe2O3/MoO3/AgBr nanocomposites with enhanced photocatalytic activity under visible light irradiation for organic pollutant degradation

    , Article Advanced Powder Technology ; Volume 31, Issue 1 , 2020 , Pages 493-503 Salari, H ; Kohantorabi, M ; Sharif University of Technology
    Elsevier B.V  2020
    In the present work, the novel ternary Fe2O3/MoO3/AgBr photocatalyst with different dosages of AgBr was successfully synthesized via a facile method. The physicochemical properties of the resultant catalyst were characterized by using various techniques such as XRD, SEM, EDX, BET, XPS, DRS, and VSM. The photocatalytic performance of as-prepared samples was evaluated by degradation of organic dye acid blue 92 (AB92) under visible light irradiation, and in dark. The impact of different operating parameters namely calcination temperature, amount of photocatalyst, dye concentration, and pH of solution were investigated in degradation reaction. Ternary nanocomposite exhibited the best... 

    Comparison between two different hemichromes of hemoglobins (HbA and HbS) induced by n-dodecyl trimethylammonium bromide: Chemometric study

    , Article Colloids and Surfaces B: Biointerfaces ; Volume 63, Issue 2 , 2008 , Pages 183-191 ; 09277765 (ISSN) Mojtahedi, M ; Parastar, H ; Jalali Heravi, M ; Chamani, J ; Chilaka, F. C ; Moosavi Movahedi, A. A ; Sharif University of Technology
    The interaction of n-dodecyl trimethylammonium bromide (DTAB) with oxyhemoglobin A and oxyhemoglobin S is investigated using UV-visible absorption spectra and chemometric resolution techniques. Oxyhemoglobins (A and S) induced to partial oxidized form (ferrihemoglobin) by DTAB and finally transform to fully oxidized hemichrome. Hemichrome mole fractions of HbS are more than HbA because of more hydrophobic interaction of DTAB-HbS in second set of binding site relative to DTAB-HbA. The visible spectra between 500 and 650 nm are used for identifying the present components in solution because each species of hemoglobin has a specific spectrum in this region. The number of components and mole... 

    Encapsulation strategies for highly stable perovskite solar cells under severe stress testing: damp heat, freezing, and outdoor illumination conditions

    , Article ACS Applied Materials and Interfaces ; Volume 13, Issue 38 , 2021 , Pages 45455-45464 ; 19448244 (ISSN) Mohammadi, M ; Gholipour, S ; Malekshahi Byranvand, M ; Abdi, Y ; Taghavinia, N ; Saliba, M ; Sharif University of Technology
    American Chemical Society  2021
    A key direction toward managing extrinsic instabilities in perovskite solar cells (PSCs) is encapsulation. Thus, a suitable sealing layer is required for an efficient device encapsulation, preventing moisture and oxygen ingression into the perovskite layer. In this work, a solution-based, low-cost, and commercially available bilayer structure of poly(methyl methacrylate)/styrene-butadiene (PMMA/SB) is investigated for PSCs encapsulation. Encapsulated devices retained 80% of the initial power conversion efficiency (PCE) at 85 °C temperature and 85% relative humidity after 100 h, while reference devices without SB (only PMMA) suffer from rapid and intense degradation after only 2 h, under the... 

    Controlling aspect ratio of colloidal silver nanorods using response surface methodology

    , Article Colloids and Surfaces A: Physicochemical and Engineering Aspects ; Volume 393 , 2012 , Pages 46-52 ; 09277757 (ISSN) Hormozi Nezhad, M. R ; Jalali Heravi, M ; Robatjazi, H ; Ebrahimi Najafabadi, H ; Sharif University of Technology
    The properties of metallic nanorods vary due to changes in their composition, size and shape, which all depend on the aspect ratio of the nanorods. This work focuses on the optimization of the aspect ratio of silver nanorods using response surface methodology (RSM). Seed-mediated approach, which is the newest method with less difficulty, has been used for the synthesis of silver nanorods. First, silver ions were reduced with sodium borohydride in the presence of sodium citrate dehydrate, as stabilizer. Then, the prepared seeds were added to a solution containing more metal salts, a weak reducing agent (ascorbic acid) and a rod-like micellar template (cetyltrimethylammonium bromide, CTAB).... 

    Investigation on the solubility of SO2 and CO2 in imidazolium-based ionic liquids using NPT Monte Carlo simulation

    , Article Journal of Physical Chemistry B ; Volume 115, Issue 46 , 2011 , Pages 13599-13607 ; 15206106 (ISSN) Ghobadi, A. F ; Taghikhani, V ; Elliott, J. R ; Sharif University of Technology
    The solubility of sulfur dioxide (SO2) and carbon dioxide (CO2) at P = 1 bar in a series of imidazolium-based room-temperature ionic liquids (RTILs) is calculated by Monte Carlo simulation in NPT ensemble using the OPLS-UA force field and Widom particle insertion method. The studied ILs were 1-butyl-3-methylimidazolium ([bmim]+) tetrafluoroborate ([BF4]-), [bmim]+ hexafluorophosphate ([PF 6]-), [bmim]+ bromide ([Br]-), [bmim]+ nitrate ([NO3]-), [bmim]+ bis-(trifluoromethyl) sulfonylimide ([Tf2N]-), and 1-ethyl-3-methylimidazolium tetrafluoroborate ([emim][BF4]). To validate the simulations, the liquid density of studied ILs and the solubility of CO2 in [bmim][PF6] was compared with... 

    Multiresidue determination of pesticides from aquatic media using polyaniline nanowires network as highly efficient sorbent for microextraction in packed syringe

    , Article Analytica Chimica Acta ; Volume 740 , 2012 , Pages 43-49 ; 00032670 (ISSN) Bagheri, H ; Alipour, N ; Ayazi, Z ; Sharif University of Technology
    A simple, rapid and sensitive method based on microextraction in packed syringe (MEPS), in combination with gas chromatography-mass spectrometry (GC-MS) was developed. Polyaniline (PANI) nanowires network was synthesized and used as sorbent of MEPS for the multiresidue determination of selected analytes from triazine, organochlrorine and organophosphorous pesticides in aqueous samples. The PANI nanowires network was prepared using soft template technique and its characterization was studied by scanning electron microscopy (SEM). The presence of micelles in this methodology showed to be an important parameter in shaping the growing polymer. Hexadecyltrimethylammonium bromide (HTAB) was used... 

    Adsorption of petroleum monoaromatics from aqueous solutions using granulated surface modified natural nanozeolites: Systematic study of equilibrium isotherms

    , Article Water, Air, and Soil Pollution ; Volume 217, Issue 1-4 , 2011 , Pages 611-625 ; 00496979 (ISSN) Seifi, L ; Torabian, A ; Kazemian, H ; Bidhendi, G. N ; Azimi, A. A ; Charkhi, A ; Sharif University of Technology
    Petroleum monoaromatics including benzene, toluene, ethylbenzene, and xylenes (BTEX) are among the notorious volatile organic compounds that contaminate water and soil. In this study, a surfactant- modified natural zeolite and its relevant granulated nanozeolites were evaluated as potential adsorbents for removal of petroleum monoaromatics from aqueous solutions. All experiments performed in batch mode at constant temperature of 20°C and pH of 6.8 for 48 h. The results revealed that the amount of BTEX uptake on granulated zeolites nanoparticles were remarkably higher than the parent micron size natural zeolite (in the order of four times). The isotherms data were analyzed using five models... 

    Synthesis of new hybrid nanomaterials: Promising systems for cancer therapy

    , Article Nanomedicine: Nanotechnology, Biology, and Medicine ; Volume 7, Issue 6 , 2011 , Pages 806-817 ; 15499634 (ISSN) Adeli, M ; Kalantari, M ; Parsamanesh, M ; Sadeghi, E ; Mahmoudi, M ; Sharif University of Technology
    Polyrotaxanes consisting of cyclodextrin rings, polyethylene glycol axes and quantum dot (QD) stoppers were synthesized and characterized. The molecular self-assembly of polyrotaxanes led to spindlelike nano-objects whose shape, size and position were dominated by QD stoppers. Due to their well-defined molecular self-assemblies, carbohydrate backbone, high functionality and several types of functional groups together with the high luminescence yield, synthesized hybrid nanostructures were recognized as promising candidates for biomedical applications. The potential applications of the molecular self-assemblies as drug-delivery systems was investigated by conjugation of doxorubicin (DOX) to... 

    Reinforced polydiphenylamine nanocomposite for microextraction in packed syringe of various pesticides

    , Article Journal of Chromatography A ; Volume 1222 , January , 2012 , Pages 13-21 ; 00219673 (ISSN) Bagheri, H ; Ayazi, Z ; Es'haghi, A ; Aghakhani, A ; Sharif University of Technology
    Reinforced polydiphenylamine (PDPA) nanocomposite was synthesized by oxidation of diphenylamine in 4molL-1 sulfuric acid solution containing a fixed amount of carbon nanotubes (CNTs) in the presence of cetyltrimethylammonium bromide (CTAB). The surface characteristic of PDPA and PDPA/CNT nanocomposites was investigated using scanning electron microscopy (SEM). The prepared PDPA/CNT nanocomposite was used as an extraction medium for microextraction in packed syringe (MEPS) of selected pesticides from aquatic environment. The effect of CNT doping level and the presence of surfactant on the extraction capability of nanocomposite was investigated and it was revealed that when 4% (w/w) of CNT in...