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synthesis-and-characterizations
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Hydrothermal synthesis and characterization of titanium dioxide nanotubes as novel lithium adsorbents
, Article Materials Research Bulletin ; Vol. 61, issue , January , 2014 , p. 70-75 ; Hajipour, H ; Askari, M ; Nusheh, M ; Sharif University of Technology
Abstract
The ion exchange process is a promising method for lithium extraction from brine and seawater having low concentrations of this element. To achieve this goal, it is vital to use an effective adsorbent with maximum lithium adsorption potential together with a stable structure during extraction and insertion of the ions. In this study, titanium dioxide and then lithium titanate spinel with nanotube morphology was synthesized via a simple two-step hydrothermal process. The produced Li4Ti5O12 spinel ternary oxide nanotube with about 70 nm diameter was then treated with dilute acidic solution in order to prepare an adsorbent suitable for lithium adsorption from local brine. Morphological and...
Synthesis and characterization of salep sulfate and its utilization in preparation of heavy metal ion adsorbent
, Article Journal of Applied Polymer Science ; Volume 130, Issue 4 , 2013 , Pages 3001-3008 ; 00218995 (ISSN) ; Doulabi, M ; Alamolhoda, A. A ; Tavakkoli, E ; Amirshekari, S ; Sharif University of Technology
2013
Abstract
A multicomponent polysaccharide obtained from dried tubers of certain natural terrestrial orchids was chemically modified by sulfonation using chlorosulfonic acid-dimethylformamide (HClSO3-DMF) complex as a reagent. For a structural characterization of salep sulfate 1H nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) spectra, and Thermogravimetric analysis (TGA) curves were recorded. The sulfate content of modified salep was determined using elemental analysis. This modified biopolymer was used to prepare a new environment-friendly heavy metal ion adsorbent, salep sulfate-graft-polyacrylic acid hydrogel (SS-g-PAA). Swelling rate and equilibrium water absorbency in various...
Synthesis and characterization of TiO2-graphene nanocomposites modified with noble metals as a photocatalyst for degradation of pollutants
, Article Applied Catalysis A: General ; Volume 462-463 , 2013 , Pages 82-90 ; 0926860X (ISSN) ; Esfandiar, A ; Rahman Setayesh, S ; Habibi Yangjeh, A ; Iraji Zad, A ; Gholami, M. R ; Sharif University of Technology
2013
Abstract
TiO2-graphene (TiO2-GR) nanocomposites were synthesized using photocatalytic reduction method. TiO2-GR nanocomposites were thereafter doped with noble metals (Pt and Pd) by chemical reduction of the corresponding cations. The samples were characterized by different techniques. The addition of GR to TiO2 decreases the crystalline size of TiO2 due to the homogeneous dispersion of the TiO2 nanoparticles on GR sheets and prevention of coagulation of TiO2 nanoparticles during synthesis process. In addition, the surface area of TiO2 was increased by addition of GR and deposition of noble metals which helps to prevent agglomeration of graphene sheets and TiO 2 nanoparticles. Red shifts to the...
Synthesis and characterization of bioactive glass/forsterite nanocomposites for bone and dental implants
, Article Ceramics - Silikaty ; Volume 56, Issue 4 , 2012 , Pages 331-340 ; 08625468 (ISSN) ; Yazdanpanah, A ; Moztarzadeh, F ; Ravarian, R ; Moztarzadeh, Z ; Tahmasbi, M ; Mozafari, M ; Sharif University of Technology
2012
Abstract
In this research, bioactive glass (BG) of the type CaO-P2O 5-SiO2 and nanocrystalline forsterite (NF) bioceramic were successfully synthesized via sol-gel processing method. Heat-treatment process was done to obtain phase-pure nanopowders. After characterization of each sample, the nanocomposite samples were prepared by cold pressing method and sintered at 1000°C. The samples were fully characterized by X-ray powder diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR) analyses. The average nanocrystallite size was determined using the Debye-Scherrer's formula 19.6 nm. The bioactivity was examined in vitro...
Synthesis and characterization of ultrasound assisted "graphene oxide-magnetite" hybrid, and investigation of its adsorption properties for Sr(II) and Co(II) ions
, Article Applied Surface Science ; Volume 353 , 2015 , Pages 350-362 ; 01694332 (ISSN) ; Outokesh, M ; Moradi, S ; Doram, A ; Sharif University of Technology
Elsevier
2015
Abstract
Magnetite nanoparticles with a size distribution of 15-21 nm were synthesized and decorated onto surface of graphene oxide by ultrasound assisted precipitation. Size and size distribution of the obtained M-GO hybrid were appreciably finer than the hybrids prepared by stirring method. M-GO is a superparamagnetic material with saturation magnetization of 31 emu g-1. The Langevin equation was successfully applied for estimation of size of Fe3 O4 nanoparticles in M-GO hybrid, with maximum error of 17.5%. The study put forward a formation mechanism for M-GO, based on instrumental analyses. Adsorption isotherms of Sr2+ and Co2+ ions, which were fitted by Langmuir monolayer...
Synthesis and characterization of novel 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazatetracyclo dodecane based nanopolymer-bonded explosives by microemulsion
, Article Journal of Molecular Liquids ; Volume 206 , June , 2015 , Pages 190-194 ; 01677322 (ISSN) ; Soleyman, R ; Zarandi, M ; Sharif University of Technology
Elsevier
2015
Abstract
2,4,6,8,10,12-Hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazatetracyclo dodecane (CL-20)-based polymer/plastic bonded explosives are used in propellant formulation. It can be predicted that CL-20-based nano-polymer/plastic bonded explosives are able to have reduced composite sensitivity and superior mechanical strength. In the current study, we have prepared two kinds of CL-20-based nano-polymer/plastic bonded explosives with ethylene-vinyl acetate copolymer and glycidyl azide polymer via the microemulsion method. Several visual techniques such as SEM/AFM/TEM techniques have been utilized for complete characterization of CL-20-based...
Hydrothermal synthesis and characterization of titanium dioxide nanotubes as novel lithium adsorbents
, Article Materials Research Bulletin ; Volume 61 , 2015 , Pages 70-75 ; 00255408 (ISSN) ; Hajipour, H ; Askari, M ; Nusheh, M ; Sharif University of Technology
Elsevier Ltd
2015
Abstract
The ion exchange process is a promising method for lithium extraction from brine and seawater having low concentrations of this element. To achieve this goal, it is vital to use an effective adsorbent with maximum lithium adsorption potential together with a stable structure during extraction and insertion of the ions. In this study, titanium dioxide and then lithium titanate spinel with nanotube morphology was synthesized via a simple two-step hydrothermal process. The produced Li4Ti5O12 spinel ternary oxide nanotube with about 70 nm diameter was then treated with dilute acidic solution in order to prepare an adsorbent suitable for lithium adsorption from local brine. Morphological and...
Synthesis and characterization of nanocrystalline barium strontium titanate
, Article Materials Science- Poland ; Volume 28, Issue 2 , 2010 , Pages 421-426 ; 01371339 (ISSN) ; Nemati, Z. A ; Faghihi Sani, M. A ; Sharif University of Technology
2010
Abstract
Barium strontium titanate (BST) was prepared via the simple sol-gel method by using tetrabutyl ti-tanate, ethanol, citric acid and ethylene glycol as starting materials. Thermogravimetry and differential thermal analysis were used to examine the behaviour of the xerogel. The particle size of BST was approximately 21 nm, as calculated by the X-ray diffraction and confirmed by transition electron microscopy for the calcination temperature of 750 °C. It was found that the particles of BST powders calcined at 750 °C were smaller and more homogeneous and uniform than those obtained at 800 °C
Synthesis and characterization of LiNiO2 nanopowder with various chelating agents
, Article Journal of Nanomaterials ; Volume 2010 , March , 2010 ; 16874110 (ISSN) ; Asgari, S ; Sharif University of Technology
2010
Abstract
LiNiO2 powders were synthesized with acrylic acid, citric acid, oxalic acid, and triethanolamine (TEA) as a chelating agent. Crystallized LiNiO2 was synthesized in air at a calcinations temperature of 500 °C for 12 hours, when the molar ratio of chelating agents to total metal ion (RPM) was 1.0. The TEA-assisted method had the highest intensity ratio of (003)/(104) peaks of X-ray diffraction (XRD) spectrum. The transmission electron microscopy (TEM) analysis indicates that the sample prepared with triethanolamine obtained the smallest particle size with average particle size of only 12nm. The results indicate that chelating agents have an important role in the intensity ratio of (003)/(104)...
Synthesis and characterization of alumina flakes/polymer composites
, Article Journal of Applied Polymer Science ; Volume 115, Issue 6 , 2010 , Pages 3716-3720 ; 00218995 (ISSN) ; Iraji Zad, A ; Jafar Tafreshi, M ; Salartayefeh, S ; Sharif University of Technology
Abstract
Alumina flakes were prepared by solution combustion method and milled to provide powder. XRD and SEM data exhibited microsized flakes with 100 nm thickness and nanosized grains. Then the powders were dispersed in polystyrene (PS) and poly methyl methacrylate (PMMA) matrixes and thin sheets of composites were produced by solution method. Mechanical properties of the composites were characterized using tensile test and their fracture surfaces, elemental composition and hydrophobic property were tested by SEM, EDX and contact angle techniques, respectively. The results exhibited better mechanical properties compared to pure polymer samples i.e. the elastic modulus in PMMA and PS composites,...
Effect of casting solvent on the characteristics of nafion/TiO2 nanocomposite membranes for microbial fuel cell application
, Article International Journal of Hydrogen Energy ; Volume 41, Issue 1 , 2016 , Pages 476-482 ; 03603199 (ISSN) ; Mousavi, S. A ; Sharif University of Technology
Elsevier Ltd
2016
Abstract
Synthesis and characterization of Nafion/TiO2 membranes (TiO2 1 wt%) with different solvents (DMF, DMAc, NMP) for proton exchange membrane operating at Microbial Fuel Cell (MFC) was investigated in this study. Nanocomposite membranes are studied due to their better physical properties and higher production voltage in comparison with Nafion 112 in MFC systems. Nafion/TiO2 nanocomposite membranes were prepared by solution casting Method. The structures of membranes were investigated by Scanning Electron Microscopy (SEM). In addition, water uptake, proton conductivity, and ion exchange capacity (IEC) of membranes were measured and compared with Nafion 112 in microbial fuel cell. The...
Synthesis and characterization of anatase-coated multiwall carbon nanotube for improvement of photocatalytic activity
, Article International Journal of Engineering, Transactions A: Basics ; Volume 30, Issue 4 , 2017 , Pages 543-550 ; 17281431 (ISSN) ; Sadrnezhaad, S. K ; Sharif University of Technology
Materials and Energy Research Center
2017
Abstract
Sol-gel technique was used to coat multiwall carbon nanotubes (MWCNTs) with anatase titania to increasing the surface area and improve the photocatalytic activity of TiO2. Room temperature ballistic conduct of MWCNT combined with semiconducting behavior of anatase brought about a photocatalytic improvement of ∼37 % with respect to the highest methyl orange decolorization flair. For characterization and photocatalytic efficiency determination, X-ray diffraction (XRD), field emission (FE) scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), diffuse reflectance spectroscopy (DRS) and ultraviolet visible (UV-vis) spectroscopy were rehearsed. Attachment of anatase...
Synthesis and characterization of supportless Ni-Pd-CNT nanocatalyst for hydrogen production via steam reforming of methane
, Article International Journal of Hydrogen Energy ; Volume 43, Issue 3 , 2018 , Pages 1319-1336 ; 03603199 (ISSN) ; Sadrnezhaad, S. K ; Malekjafarian, M ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
Supportless Ni-Pd-0.1CNT foamy nanocatalyst with specific surface area of 611.3 m2/g was produced by electroless deposition of nickel, palladium and multiwall carbon nanotube (MWCNT) on interim polyurethane substrate. Application of temperature programmed reduction (TPR) and temperature programmed oxidation (TPO) data into Kissinger (Redhead) kinetic model showed lessening of their activation energies due to Pd and CNT addition. Presence of foamy Ni/SiC caused 8% higher steam reforming of methane; while Ni-Pd-0.1CNT presence resulted in 22% higher methane conversion. The catalytic behavior of the samples was described by morphological and compositional studies which were carried out by...
Synthesis and characterization of photocatalytically active crumpled-shape nanocomposites of nitrogen and sulfur co-doped ZnO–CeO2
, Article Solar Energy Materials and Solar Cells ; Volume 203 , 2019 ; 09270248 (ISSN) ; Sabour Rouh Aghdam, A ; Nazari, M ; Bayat, A ; Saievar Iranizad, E ; Najafi Liavali, M ; Sharif University of Technology
Elsevier B.V
2019
Abstract
In this study, crumpled-shape nanocomposite of nitrogen and sulfur co-doped ZnO–CeO2 (NSZC) was deposited on FTO substrate using one-step ultrasonic spray pyrolysis. Zinc acetate, cerium nitrate, and thiourea were dissolved in deionized water and used as starting solution. The samples were characterized using FESEM, XRD, UV–vis spectroscopy, EIS, and PL. The as-prepared nitrogen and sulfur co-doped ZnO–CeO2 nanocomposites were evaluated as high photocatalysts for degradation of methyl orange. Nearly 100% photocatalytic degradation of methyl orange was achieved for 180 min. The photoluminescence and electrochemical impedance spectroscopy revealed that co-doping of nitrogen and sulfur could...
Synthesis and characterization of a new zwitterionic palladium complex as an environmentally friendly catalyst for the Heck-Mizoroki coupling reaction in GVL
, Article Molecular Catalysis ; Volume 474 , 2019 ; 24688231 (ISSN) ; Mahmoudi, H ; Ataie, S ; Bahjati, M ; Kia, R ; Raithby, P. R ; Vaccaro, L ; Sharif University of Technology
Elsevier B.V
2019
Abstract
A new zwitterionic Palladium (II) complex has been synthesized by the one-pot mixing of Pd(OAc)2, 2-aminophenol and (3-formyl-4-hydroxy-5-methylbenzyl) triphenylphosphonium chloride, in refluxing ethanol. The metal complex formed was characterized by 1H NMR, 13C NMR, 31P NMR and X-ray crystallographic technique and its efficiency tested as a homogeneous pre-catalyst in Heck-Mizoroki cross coupling reaction using γ-Valerolactone (GVL) as a biomass-derived green medium. All the products were obtained in good to excellent yields. © 2019
Hierarchical rutile/anatase TiO 2 nanorod/nanoflower thin film: Synthesis and characterizations
, Article Materials Science in Semiconductor Processing ; Volume 93 , 2019 , Pages 252-259 ; 13698001 (ISSN) ; Eslami Saed, A ; Sadrnezhaad, S. K ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
Hierarchical TiO 2 nanorod/nanoflower thin film was synthesized on fluorine doped tin oxide glass via hydrothermal and aqueous chemistry methods. According to field emission scanning electron microscopy results, the thin film was crack-free and uniform. Primary nanorods had an average diameter of 95 nm and a length of 2 µm. They were perpendicular to the substrate owing to the TiO 2 prenucleation. Growth of the nanoflowers on the nanorods could increase both the specific surface area and roughness. X-ray diffraction and Raman spectroscopy showed that the nanorods were rutile; while the nanoflowers were anatase. Efficient electron transfer from anatase to rutile could therefore occur....
Synthesis and characterization of rGO/Fe2O3 nanocomposite as an efficient supercapacitor electrode material
, Article Journal of Materials Science: Materials in Electronics ; Volume 31, Issue 17 , 2020 , Pages 14998-15005 ; Nemati, A ; Malek Khachatourian, A ; Golmohammad, M ; Sharif University of Technology
Springer
2020
Abstract
The reduced graphene oxide-Fe2O3 (rGO-Fe2O3) nanocomposites were synthesized by a facile and low-cost hydrothermal method employing rGO and Iron (III) nitrate precursors. The synthesis parameters including the reduction time and presence of reduction aid are studied. The structural and morphological studies of the nanocomposites were investigated by using Raman spectra, Fourier transform infrared spectroscopy, X-ray diffraction, and field emission scanning electron microscopy. The results indicate that Fe2O3 nanoparticles with average particle size of 25 nm are well anchored on graphene sheets and the weight percent of the nanoparticles in the nanocomposites was influenced by the reduction...
Synthesis and characterization of 3D-printed functionally graded porous titanium alloy
, Article Journal of Materials Science ; Volume 55, Issue 21 , 22 April , 2020 , Pages 9082-9094 ; Farahmand, F ; Pourdanesh, F ; Torshabi, M ; Al Janabi, A. H ; Rasoulianboroujeni, M ; Tayebi, L ; Tabatabaei, F. S ; Sharif University of Technology
Springer
2020
Abstract
This study aims to 3D print titanium alloy constructs incorporating gradient of porosities, from the fully dense core to the porous outer surface. Gradient porous specimens were prepared using selective laser melting (SLM). Fully dense specimens fabricated by SLM were used as the control group. Characterization of samples was done using X-ray tomography, uniaxial compression testing, and optical and scanning electron microscopes. The biocompatibility of fabricated samples was investigated using human periodontal ligament stem cells via assessment of cell attachment, viability, and proliferation by direct and indirect assays. The data were analyzed using ANOVA and Tukey’s post hoc test....
Synthesis and characterization of multi stimuli-responsive block copolymer-silica hybrid nanocomposite with core-shell structure via RAFT polymerization
, Article Composites Science and Technology ; Volume 188 , 2020 ; Rahemipoor, S ; Kohestanian, M ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
A novel multi stimuli-responsive silica nanocomposite with a core-shell structure is synthesized using reversible addition-fragmentation chain transfer (RAFT) polymerization. The SiO2 nanoparticles are chemically modified via 3-(trimethoxylsilyl) propyl methacrylate (MPS) which they are used in the core of nanocomposite. The macro-RAFT agent is prepared by RAFT polymerization of N-isopropylacrylamide (NIPAM), spirooxazine acryloyl monomer (SOM), and 2-(dodecylthiocarbonothioylthio)-2-methylpropionic acid (DDMAT as a RAFT agent). Finally, the smart nanocomposite is prepared by reaction between the macro-RAFT agent and 2-(Dimethylamino) ethyl methacrylate (DMAEMA) as a monomer. SOM as a...
Synthesis and characterization of bagasse poly(methyl methacrylate) graft copolymer
, Article Macromolecular Symposia ; Volume 274, Issue 1 , 2008 , Pages 49-54 ; 10221360 (ISSN) ; Pourjavadi, A ; Noei Aghaei, M. A ; Sharif University of Technology
2008
Abstract
Graft copolymerization of methyl methacrylate (MMA) was carried out on bagasse fibers in an aqueous medium using eerie ammonium nitrate (CAN) as initiator under a neutral atmosphere. In order to obtain the optimum condition for graft copolymerization, the effects of initiator concentration, temperature, time of reaction, and monomer concentration were studied. The maximum grafting percent was found to be 122%. The bagasse grafted poly(methyl methacrylate) was characterized by FTIR and its thermal behavior was characterized by TGA. Copyright © 2008 WILEY-VCH Verlag GmbH & Co. KGaA