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    New polysaccharide-g-polyacrylonitrile copolymers: synthesis and thermal characterization [electronic resource]

    , Article Polymers for Advanced Technologies ; Volume 14, Issue 7, pages 508–516, July 2003 Zohurian Mehr, M. J. (Mohammad Jalal) ; Pourjavadi, Ali ; Sharif University of Technology
    Abstract
    Various natural and modified polysaccharides (i.e. arabic gum, tragacanth gum, xanthan gum, sodium alginate, chitosan, sodium carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose) were modified using ceric-initiated graft polymerization of acrylonitrile under inert atmosphere. Grafting was confirmed using spectral (FT-IR) proofs. The grafting parameters were determined by conventional methods. Thermal characteristics of the homopolymer-free copolymers were studied using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) under nitrogen atmosphere. The major thermal transitions as well as the activation energy of the major decomposition stages were... 

    Synthesis and thermogravimetric analysis of inclusion complexes of O2N2-donor Aza-crown macrocyclic ligands with [60]fullerene

    , Article Journal of Thermal Analysis and Calorimetry ; Volume 118, Issue 3 , 2014 , pp 1631-1637 ; ISSN: 13886150 Ghanbari, B ; Gholamnezhad, P ; Hatami, M ; Sharif University of Technology
    Abstract
    A simple method for the formation of inclusion complex of [60]fullerene with two O2N2-donor aza-crown macrocyclic ligands was introduced. The products were characterized using UV-vis and IR spectroscopies as well as HPLC, and ESI mass spectrometry. The ESI mass and elemental analysis data revealed that the ratio of macroring:[60]fullerene were not the same. The binding capability of the macrorings as well as the number of the macroring addends to [60]fullerene were investigated using thermogravimetric analysis (TG) and differential scanning calorimetry (DSC). Considering percentage mass loss in different steps of TG and the enthalpy changes in DSC found for each of these products, the number... 

    New polysaccharide-g-polyacrylonitrile copolymers: Synthesis and thermal characterization

    , Article Polymers for Advanced Technologies ; Volume 14, Issue 7 , 2003 , Pages 508-516 ; 10427147 (ISSN) Zohuriaan Mehr, M. J ; Pourjavadi, A ; Sharif University of Technology
    2003
    Abstract
    Various natural and modified polysaccharides (i.e. arabic gum, tragacanth gum, xanthan gum, sodium alginate, chitosan, sodium carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose) were modified using cericinitiated graft polymerization of acrylonitrile under inert atmosphere. Grafting was confirmed using spectral (FT-IR) proofs. The grafting parameters were determined by conventional methods. Thermal characteristics of the homopolymer-free copolymers were studied using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) under nitrogen atmosphere. The major thermal transitions as well as the activation energy of the major decomposition stages were... 

    Study of thermal behavior of CrO3 using TG and DSC

    , Article Journal of Thermal Analysis and Calorimetry ; Vol. 116, Issue. 2 , 2014 , pp. 915-921 ; ISSN: 13886150 Sajadi, S. A. A ; Khaleghian, M ; Sharif University of Technology
    Abstract
    Using two techniques of thermogravimetry and differential scanning calorimetry under O2 and N2 gas atmosphere from 25 to 600 °C, the thermal behavior of chromium(VI) oxide CrO3 was investigated. The identity of products at different decomposition steps was confirmed by XRD technique. Both techniques produced similar results supporting the same steps for the compound. The received products were investigated by SEM electron microscope. The form and the size of crystals were investigated. Three distinct energy changes were observed, namely, two endothermic and one exothermic in DSC. The amount of ΔH for each peak is also reported  

    A novel phenolic ionic liquid for 1.5 molar CO2 capture: Combined experimental and DFT studies

    , Article RSC Advances ; Volume 5, Issue 71 , Jun , 2015 , Pages 58005-58009 ; 20462069 (ISSN) Vafaeezadeh, M ; Aboudi, J ; Mahmoodi Hashemi, M ; Sharif University of Technology
    Royal Society of Chemistry  2015
    Abstract
    A phenolic-based ionic liquid (IL), 1-(2-hydroxyethyl)-2,3-dimethylimidazolium phenoxide has been introduced for 1.5 molar carbon dioxide (CO2) absorption at ambient conditions without using special methodologies or precautions. The structure of the IL was characterized by various methods such as FT-IR, 1H NMR, 13C NMR, elemental analysis (EA) and thermogravimetric analysis (TGA). The ability of this IL for CO2 uptake reaches to its maximum value after 2 h. The IL has been reused fr several times with constant efficiency. Density functional theory (DFT) calculations at the B3LYP/6-311++G∗∗ level of calculation have been carried out to gain more structural knowledge... 

    Polarity adjustment of a nanosilica-functionalized polyamine modified by ionic liquid for removal of Cu2+ from aqueous solutions

    , Article RSC Advances ; Volume 6, Issue 17 , 2016 , Pages 14128-14133 ; 20462069 (ISSN) Vafaeezadeh, M ; Mahmoodi Hashemi, M ; Ghavidel, N ; Sharif University of Technology
    Royal Society of Chemistry  2016
    Abstract
    The current work deals with modification of the surface of a silica-polyamine with amine-based ionic liquid (IL) and its application for removal of Cu2+ from an aqueous media. The absorbent is simply prepared from commercially available reagents. The material is characterized by FT-IR spectroscopy, thermogravimetric analysis (TGA), N2 adsorption-desorption, and transmission electronic microscopy (TEM). Effects of several parameters on absorption efficiency, as well as activity of the absorbent to other metals, are also investigated. Moreover, the reusability of the absorbent is studied at the optimized condition. © The Royal Society of Chemistry 2016  

    Investigation of thermal behavior of α-PbO and β-PbO IN O2 atmosphere

    , Article Metalurgija ; Volume 57, Issue 4 , 2018 , Pages 287-290 ; 05435846 (ISSN) Sajadi, S. A. A ; Nazari Alavi, A ; Mirzai, M ; Sharif University of Technology
    Faculty of Metallurgy  2018
    Abstract
    The compounds α-lead oxide (α-PbO) and β-lead oxide (β-PbO) were purchased from Merck co. and used for thermal investigations in laboratory. The compound was heated in a thermogravimeter at different temperature, from 25 to 400 °C. The used gas atmosphere was O2. The received products were investigated by X-ray diffraction (XRD) technique. The received product Pb3O4 was confirmed by XRD. The textures of two different morphologies of α-PbO, β-PbO and the product Pb3O4 is investigated by scanning electron microscope (SEM) and transmission electron microscope (TEM) techniques. © 2018, Faculty of Metallurgy. All rights reserved  

    Thermal behavior of alkaline lead acetate, a study of thermogravimetry and differential scanning calorimetry

    , Article Scientia Iranica ; Volume 15, Issue 4 , 2008 , Pages 435-439 ; 10263098 (ISSN) Sajadi, S. A. A ; Alamolhoda, A. A ; Hashemian, S. J ; Sharif University of Technology
    Sharif University of Technology  2008
    Abstract
    The compound, alkaline lead acetate, Pb(CH3COO)2·PbO·H2O (ALA), was purchased from the Fluka Company. The X-ray diffraction film and SEM electron microgaph of this compound were obtained and reported in this paper for the first time. The thermal behavior of alkaline lead acetate (ALA) was studied using thermogravimetery (TGA) and Differential Scanning Calorimetery (DSC) techniques under an O2 gas atmosphere from 25 to 600°C. Four distinct energy changes associated with weight changes were observed, all of them being exothermic in the DSC results. The amount of ΔH for each peak is reported. © Sharif University of Technology  

    An investigation into the structure and thermal properties of lead hydroxide

    , Article Scientia Iranica ; Volume 14, Issue 2 , 2007 , Pages 169-173 ; 10263098 (ISSN) Sajadi, S. A. A ; Alamolhoda, A. A ; Hashemian, S. J ; Sharif University of Technology
    Sharif University of Technology  2007
    Abstract
    The compound, lead hydroxide Pb6O4(OH)4, was prepared by a method used for the first time in the authors laboratory. The compound was identified by XRD and it's purity was determined by analytical methods (100%). The thermal characteristics of this compound were investigated by using a thermogravimetry (TGA). This compound was found to be stable at room temperature and at 160°C will decompose completely to produce lead (II) oxide. © Sharif University of Technology, April 2007  

    Novel sulfobetaine-sulfonic acid-contained superswelling hydrogels

    , Article Polymers for Advanced Technologies ; Volume 16, Issue 9 , 2005 , Pages 659-666 ; 10427147 (ISSN) Kabiri, K ; Faraji Dana, S ; Zohuriaan Mehr, M. J ; Sharif University of Technology
    2005
    Abstract
    Novel hydrogels based on zwitterionic monomer [3-(methacrylamido)propyl] dimethyl (3-sulfopropyl) ammonium hydroxide (MPDSAH) and a strong acid monomer (2-acrylamido-2-methylpropane sulfonic acid, AMPS) were synthesized through solution polymerization under normal conditions to achieve nearly quantitative gel yield. The structure of the gels was confirmed using infrared spectroscopy. Thermal properties were simultaneously studied by differential scanning calorimetry and thermogravimetric analysis (DSC/TGA). The effects of the polymerization variables on the swelling capacity of the products were investigated. It was found that, in a certain range of the monomers mol ratio, increase of AMPS... 

    Partially aromatic polyamides based on tetraphenylthiophene diamine: synthesis and characterization

    , Article Journal of Applied Polymer Science, New York, NY, United States ; Volume 77, Issue 5 , 2000 , Pages 1144-1153 ; 00218995 (ISSN) Pourjavadi, A ; Zamanlu, M. R ; Zohuriaan Mehr, M. J ; Sharif University of Technology
    John Wiley & Sons Inc  2000
    Abstract
    Tetraphenylthiophene diamine (TPTDA) was prepared through a modified three-step route to achieve an improved overall yield. TPTDA reacted with succinic, adipic, suberic, sebasic, and fumaric acids via the Yamazaki phosphorylation method to yield novel partially aromatic polyamides (TPT series). A counterpart polyamide series based on p-phenylene diamine (Ph series) was also synthesized under the same conditions. All of the polymers were characterized by means of spectrochemical (Fourier transform infrared spectroscopy. 1H-nuclear magnetic resonance (NMR), and 13C-NMR) and thermal (differential scanning calorimetry and thermogravimetric) methods of analysis. Solubility of TPT polyamides was... 

    Pulsed laser irradiation for environment friendly reduction of graphene oxide suspensions

    , Article Applied Surface Science ; Vol. 301 , May , 2014 , pp. 183-188 ; ISSN: 01694332 Ghadim, E. E ; Rashidi, N ; Kimiagar, S ; Akhavan, O ; Manouchehri, F ; Ghaderi, E ; Sharif University of Technology
    Abstract
    Graphene oxide (GO) sheets were synthesized through a modified Hummers' method. Using high resolution transmission electron microscopy the thickness of the GO sheets in a multilayer structure of stacked GO sheets was found ∼0.8 nm. A nanosecond pulsed laser (with wavelength of 532 nm and average power of 0.3 W) was applied for effective and environment friendly reduction of the GO sheets in an ammonia solution (pH ∼9) at room temperature conditions. The deoxygenation of the GO sheets by the pulsed laser reduction method was confirmed by using UV-visible, Fourier transform infrared, X-ray photoelectron spectroscopy (XPS) and thermo gravimetric analysis. Based on XPS analysis, the O/C ratio of... 

    In situ preparation and property investigation of polypropylene/fumed silica nanocomposites

    , Article Polymer Composites ; Vol. 35, issue. 1 , January , 2014 , pp. 37-44 ; ISSN: 02728397 Azinfar, B ; Ahmad Ramazani, S. A ; Jafariesfad, N ; Sharif University of Technology
    Abstract
    We present the preparation of polypropylene (PP)/fumed silica (FS) nanocomposites via in situ polymerization in this article. The approach includes preparation and utilization of a bisupported Ziegler-Natta catalytic system in which magnesium ethoxide and FS are used as conjugate supports of the catalyst. Catalyst preparation and polymerization processes are carried out in the slurry phase and under argon atmosphere. Scanning electron microscopy images show a good dispersion of the FS throughout the PP matrix. Results from differential scanning calorimetry reveal that the crystallization temperature of prepared nanocomposites increases by increasing FS loading. Also, crystal content of... 

    Study on the catalytic activity and theoretical modeling of a novel dual acidic mesoporous silica

    , Article RSC Advances ; Volume 4, Issue 32, 2014 , 2014 , Pages 16647-16654 ; ISSN: 20462069 Vafaeezadeh, M ; Fattahi, A ; Sharif University of Technology
    Abstract
    A novel mesoporous silica-functionalized dual Brønsted acidic species has been introduced as an efficient catalyst for solvent-free esterification of fatty acids with ethanol. The structure of the catalyst has been characterized by FT-IR spectroscopy, thermal gravimetric analysis (TGA), TEM and N2 adsorption-desorption. TGA of catalyst 1 showed no weight loss before 200 °C, indicating a high degree of hydrophobicity of the surface of the mesoporous silica. TEM images and nitrogen adsorption-desorption showed no noticeable changes to the structure of the catalyst before and after acid treatment. pH metric analysis was performed for the catalyst to determine the loading of the acidic sites.... 

    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
    2013
    Abstract
    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  

    Novel cationic-modified salep as an efficient flocculating agent for settling of cement slurries

    , Article Carbohydrate Polymers ; Volume 93, Issue 2 , April , 2013 , Pages 506-511 ; 01448617 (ISSN) Pourjavadi, A ; Fakoorpoor, S. M ; Hosseini, S. H ; Sharif University of Technology
    2013
    Abstract
    A new cationic flocculant was synthesized by graft copolymerization of acrylamide (AM) and 3-(methacryloylamino)propyl]trimethylammonium chloride (MAPTAC) onto salep using free radical polymerization initiated by ammonium persulfate (APS) to produce cationic salep [S-g-P(AM-co-MAPTAC)]. Reaction parameters (monomers/salep ratio, concentration of reactants, MAPTAC/AM ratio, and APS) were optimized using a full factorial experimental design to obtain the highest settling rate for cement suspensions. The best performing product was characterized by gel permeation chromatography (GPC), FTIR, 1H NMR spectroscopy, and thermogravimetric analysis (TGA). The resulted cationic flocculant may be... 

    PEG-co-polyvinyl pyridine coated magnetic mesoporous silica nanoparticles for pH-responsive controlled release of doxorubicin

    , Article International Journal of Polymeric Materials and Polymeric Biomaterials ; Volume 64, Issue 11 , 2015 , Pages 570-577 ; 00914037 (ISSN) Pourjavadi, A ; Mazaheri Tehrani, Z ; Bennett, C ; Sharif University of Technology
    Taylor and Francis Inc  2015
    Abstract
    In the present work a pH responsive drug nanocarrier based on magnetic mesoporous silica nanoparticles (MMSN) and polyethylene glycol-co-polyvinyl pyridine (PEG-co-PVP) was prepared. The core-shell nanocarrier was formed due to electrostatic interaction between protonated polyvinyl pyridine and surface modified MMSN with carboxylate groups. This carrier was used for pH-controllable doxorubicin release. The maximum release was occurred at pH 5.5 (pH of endosomes). This carrier was characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, UV-Vis spectrophotometer, scanning electron microscope, and high-resolution transmission electron microscope techniques. Also the... 

    Comparison of microstructure and hydrogen permeability of perovskite type ACe0.9Y0.1O3-δ (A is Sr, Ba, La, and BaSr) membranes

    , Article International Journal of Hydrogen Energy ; Volume 40, Issue 20 , 2015 , Pages 6559-6565 ; 03603199 (ISSN) Heidari, M ; Safekordi, A ; Zamaniyan, A ; Ganji Babakhani, E ; Amanipour, M ; Sharif University of Technology
    Abstract
    Hydrogen permeation through ACe0.9Y0.1O3-δ (A = Sr, Ba, La, and BaSr) perovskite-type membranes was studied at high temperatures. X-ray diffraction (XRD) and thermogravimetric analysis (TGA) were used to characterize phase structure and phase stability of the membrane. The XRD results showed the formation of a single phase of perovskite structure with configuration orthorhombic for BCY and BSCY membranes. Based on the TGA results, it was found that the phase stability increases in the order of LCY < SCY < BCY < BSCY. The microstructure examinations of the synthesized membranes studied by scanning electron microscopy (SEM) showed the formation of a dense-like... 

    Thermogravimetric analysis and kinetic study of heavy oil pyrolysis

    , Article Petroleum Science and Technology ; Volume 34, Issue 10 , 2016 , Pages 911-914 ; 10916466 (ISSN) Motahari Nezhad, M ; Hami, M. R ; Sharif University of Technology
    Taylor and Francis Inc  2016
    Abstract
    ABSTRACT: Pyrolysis, so-called devolatilization, is one of the first steps of all thermochemical processes occurring in an inert atmosphere. The authors discuss the main kinetic features of heavy oil pyrolysis, on the basis of the data derived m from a TGA analysis and by using a kinetic model. The samples were heated over a range of temperature from 400 K to 430°C at various heating rates between 10 and 80°C/min. Experimental results showed that the effect of time is considerable in the case of tar conversion, compared to char and gases  

    The impact of morphology on thermal properties and aerobic biodegradation of physically compatibilized poly (lactic acid)/co-plasticized thermoplastic starch blends

    , Article Polymers for Advanced Technologies ; Volume 29, Issue 12 , 2018 , Pages 2880-2889 ; 10427147 (ISSN) Esmaeili, M ; Pircheraghi, G ; Bagheri, R ; Altstädt, V ; Sharif University of Technology
    John Wiley and Sons Ltd  2018
    Abstract
    Recently, the use of biodegradable polymers became the applicable solution to reduce the environmental concerns, which are created by plastic wastes as well as restrictions of petroleum-based synthetic polymers. By this point of view, polylactic acid (PLA) as a biodegradable and bio-based polymer is resolving both aforementioned issues. While, the high cost of PLA and its slow biodegradation rate make researchers to blend it with a faster one, for instance, thermoplastic starch (TPS). Adding TPS into PLA can influence on the morphological structure, thermal stability, and biodegradability. In this study, the well-tuned co-plasticized TPS via sorbitol/glycerol mixture was melt mixed with PLA...