Search for: room-temperature
Total 131 records
Preparation and biological evaluation of radiolabeled-folate embedded superparamagnetic nanoparticles in wild-type rats, Article Journal of Radioanalytical and Nuclear Chemistry ; Volume 287, Issue 1 , January , 2011 , Pages 119-127 ; 02365731 (ISSN) ; Hosseini Salekdeh, S. L ; Mahmoudi, M ; Yousefnia, H ; Majdabadi, A ; Pouladian, M ; Sharif University of Technology
In this study, superparamagnetic iron oxide nanoparticles (SPION) embedded by folic acid (SPION-folate) were prepared by a modified co-precipitation method. The structure, size, morphology, magnetic property and relaxivity of the SPION-folate were characterized systematically by means of XRD, VSM, HRSEM and TEM and the interaction between folate and iron oxide (Fe3O 4) was characterized by FT-IR. The particle size was shown to be ≈5-10 nm. To ensure biocompatibility, the interaction of these SPION with mouse connective tissue cells (adhesive) was investigated using an MTT assay. Consequently, gallium-67 labeled nanoparticles ([67Ga]-SPION-folate) were prepared using 67Ga with a high labeling...
Efficient and green oxidative degradation of methylene blue using Mn-doped ZnO nanoparticles (Zn
Journal of Experimental Nanoscience
Volume 10, Issue 16
; Amini, M
; Boghaei, D. M
Sharif University of Technology
Taylor and Francis Ltd 2015
Mn-doped ZnO nanoparticles, Zn
1−xMn xO, were synthesised by a polyethylene glycol (PEG) sol–gel method and the physicochemical properties of compounds were characterised by atomic absorption spectroscopy (AAS), energy-dispersive X-ray analysis, X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The catalytic degradation of an organic dye, methylene blue (MB), in the presence of Zn 1−xMn xO as the catalyst and hydrogen peroxide (H 2O 2) as the oxidant at room temperature in water has been studied. Effects of oxidant, catalyst amount, catalyst composition, pH value of the solution and an OH-radical...
Microstructural study of a High Bainite Dual Phase (HBDP) steel austempered at different temperatures, Article Defect and Diffusion Forum ; Volume 297-301 , 2010 , Pages 62-67 ; 10120386 (ISSN); 3908451809 (ISBN); 9783908451808 (ISBN) ; Ekrami, A ; Sharif University of Technology
Trans Tech Publications Ltd 2010
4340 steel bars were austenitized at 850°C for 1 hour followed by heating at 700°C (ferrite and austenite region) for 90 min and quenching into a salt bath with different temperatures of 300, 350, 400 and 450°C. The steel bars were held for 1 hour at these temperatures before air cooling to room temperature. Various ferrite-bainite microstructures with 34% volume fraction of ferrite and different bainite morphologies were obtained. The results of SEM studies showed that by increasing the austempering temperature, the morphology of bainite varies from lower to upper bainite. According to the T-T-T diagram of the studied steel, the bainite transformation will not complete for the holding time...
The two-step thermochemical growth of ZnS:Mn nanocrystals and a study of luminescence evolution, Article Nanotechnology ; Volume 20, Issue 9 , 2009 ; 09574484 (ISSN) ; Marandi, M ; Taghavinia, N ; Houshiar, M ; Sharif University of Technology
In this work we report a new thermochemical method for the synthesis of ZnS:Mn nanocrystals. Zn(NO3)2 and Na2S 2O3 were used as the precursors and Mn(NO 3)2 was the source of impurity. Thioglycerol (TG,C 3H8O2S) was also used as the capping agent and the catalyst of the reaction. Na2S2O3 is a heat sensitive material which releases S species upon heating. Consequently, the reaction proceeds in temperatures higher than room temperature. The reaction was done in two steps. In the first step, the precursors were heated at 96 °C for an hour without TG. In the second step, TG was injected to the solution and the heating process was continued for longer heating durations. A fast growth occurred in...
Direct conversion of inorganic complexes to platinum/thin oxide nanoparticles decorated on MOF-derived chromium oxide/nanoporous carbon composite as an efficient electrocatalyst for ethanol oxidation reaction, Article Journal of Colloid and Interface Science ; Volume 555 , 2019 , Pages 655-666 ; 00219797 (ISSN) ; Rezaee, S ; Shahrokhian, S ; Amini, M. M ; Sharif University of Technology
Academic Press Inc 2019
In this work, we present the design and fabrication of a novel nanocomposite based on noble metal and metal oxide nanoparticles dispersed on highly porous carbon obtained via the pyrolysis of an inorganic complex and metal-organic frameworks. This nanocomposite is prepared by a two-step procedure: first, the composite support of nanoporous carbon (NPC) is obtained by the direct carbonization of the Cr-benzene dicarboxylic ligand (BDC) MOF in an Argon atmosphere at 500 °C (Cr2O3-NPC). A mixture containing Cr2O3-NPC and [PtCl(SnCl3)(SMe2)2] is then prepared, and underflow of Argon is heated to 380 °C. Finally, Pt-SnO2 nanoparticles are loaded on the Cr2O3-NPC support, and the obtained...
Ag-doped magnetic metal organic framework as a novel nanostructured material for highly efficient antibacterial activity, Article Environmental Research ; Volume 188 , 2020 ; Abdi, J ; Vossoughi, M ; Alemzadeh, I ; Sharif University of Technology
Academic Press Inc 2020
In the last decades, numerous attempts have been made to prevent microbial pollution spreading, using antibacterial agents. Zeolitic imidazolate framework-8 (ZIF-8) belongs to a subgroup of metal organic frameworks (MOFs) merits of attention due to the zinc ion clusters and its effective antibacterial activity. In this work, Ag-doped magnetic microporous γ-Fe2O3@SiO2@ZIF-8-Ag (FSZ-Ag) was successfully synthesized by a facile methodology in room temperature and used as an antibacterial agent against the growth of the Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus bacteria. Several characterization methods were applied to analyze the properties of the materials, and the...
Improved green biosynthesis of chitosan decorated Ag- and Co3O4-nanoparticles: A relationship between surface morphology, photocatalytic and biomedical applications, Article Nanomedicine: Nanotechnology, Biology, and Medicine ; Volume 32 , 2021 ; 15499634 (ISSN) ; Rabiee, N ; Bagherzadeh, M ; Ghadiri, A.M ; Fatahi, Y ; Dinarvand, R ; Webster, T. J ; Sharif University of Technology
Elsevier Inc 2021
AgNPs@Chitosan and Co3O4-NPs@Chitosan were fabricated with Salvia hispanica. Results showed MZI values of 5 and 30 mm for Co3O4-NPs- and AgNPs@Chitosan against S. aureus, and 15 and 21 mm for Co3O4-NPs- and AgNPs@Chitosan against E. coli (24 h, 20 μg/mL), respectively. MTT assays showed up to 80% and 90%, 71% and 75%, and 91% and 94% mammalian cell viability for the green synthesized, chemically synthesized AgNPs and green synthesized AgNPs@Chitosan for HEK-293 and PC12 cells, respectively, and 70% and 71%, 59% and 62%, and 88% and 73% for the related Co3O4-NPs (24 h, 20 μg/mL). The photocatalytic activities showed dye degradation after 135 and 105 min for AgNPs@Chitosan and...
Novel one-pot synthesis of functionalized quinolines from isocyanides, aniline, and acetylene dicarboxylate via cu-catalyzed intramolecular C─H activation reactions, Article Journal of Heterocyclic Chemistry ; Volume 56, Issue 4 , 2019 , Pages 1254-1259 ; 0022152X (ISSN) ; Rezaee, E ; Jahani, M ; Tabatabai, S. A ; Sharif University of Technology
The one-pot synthesis of a novel class of substituted quinoline derivatives with good yields is achieved via the Cu-catalyzed intramolecular C─H activation reaction between isocyanides, aniline, and acetylene dicarboxylate in MeCN at room temperature. The existence of one-pot conditions, availability of a starting material-catalyst, the absence of column chromatography, and a high yield of products are among the advantages of this method. The structures are confirmed spectroscopically (1H NMR and 13C NMR, IR, and EI-MS) and through elemental analyses
Injectable in situ forming kartogenin-loaded chitosan hydrogel with tunable rheological properties for cartilage tissue engineering, Article Colloids and Surfaces B: Biointerfaces ; Volume 192 , 2020 ; Chen, Y ; Wang, D ; Bagheri, R ; Solouk, A ; Wu, H ; Sharif University of Technology
Elsevier B.V 2020
Limited regeneration capacity of cartilage can be addressed by tissue engineering approaches including localized delivery of bioactive agents using biomaterials. Although chitosan hydrogels have been considered as appropriate candidates for these purposes, however, their poor mechanical properties limit their real applications. Here, we develop in situ forming chitosan hydrogels with enhanced shear modulus by chemical modification of chitosan using N-(β-maleimidopropyloxy) succinimide ester (BMPS). Moreover, we utilize β-Glycerophosphate (β-GP) in the hydrogels for achieving thermosensitivity. We investigate the effects of BMPS, β-GP and chitosan concentration on rheological and swelling...
The geometrical characteristics of nickel-based metal organic framework on its entrapment capability, Article Journal of Chromatography A ; Volume 1610 , 2020 ; Abbasi, A ; Bagheri, H ; Sharif University of Technology
Elsevier B.V 2020
Here, a three dimensional nickel–based metal organic framework (MOF) was synthesized via solvothermal and room temperature protocols. In order to study the effects of the synthesis conditions on the physical properties such as pore sizes and shapes of the prepared MOFs, their extraction capabilities were examined. Both MOFs were characterized by Fourier transform infrared spectroscopy, powder X-ray diffraction, scanning electron microscopy, Brunauer–Emmett–Teller and thermogravimetric analyses. Brilliant properties such as porous structure, high surface area and considerable thermal stability make them reasonable candidates to be employed as efficient extractive phases. The efficiency of the...
Optical and electrical properties of the copper-carbon nanocomposites, Article Nanophotonics II, Strasbourg, 7 April 2008 through 9 April 2008 ; Volume 6988 , 2008 ; 0277786X (ISSN); 9780819471864 (ISBN) ; Vesaghi, M. A ; Shafiekhani, A ; Ahmadi, M ; Sharif University of Technology
We prepared copper-carbon nanocomposite films by co-deposition of RF-Sputtering and RF-PECVD methods at room temperature. These films contain different copper concentration and different size of copper nanoparticles. The copper content of these films was obtained from Rutherford Back Scattering (RBS) analyze. We studied electrical resistivity of samples versus copper content. A metal-nonmetal transition was observed by decreasing of copper content in these films. The electrical conductivity of dielectric and metallic samples was explained by tunneling and percolation models respectively. In the percolation threshold conduction results from two mechanisms: percolation and tunneling. In the...