Search for: room-temperature
Total 131 records
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...
Water repellent room temperature vulcanized silicone for enhancing the long-term stability of perovskite solar cells, Article Solar Energy ; Volume 218 , 2021 , Pages 28-34 ; 0038092X (ISSN) ; Heydari, M ; Mohammadi, M ; Parand, P ; Taghavinia, N ; Sharif University of Technology
Elsevier Ltd 2021
A key direction toward enhancing the long term and outdoor stability of the perovskite solar cells is encapsulation. As a result, a suitable encapsulation package is required to prevent moisture and oxygen penetration toward the perovskite solar cells. In this work, a low-cost commercially available bilayer structure of poly (methyl methacrylate)/ room-temperature vulcanizing silicone rubber (RTV) encapsulation package for enhancing the long term stability of the perovskite solar cells has been investigated. Encapsulated cells retained more than 80% of the initial efficiency at the environmental condition of 50% moisture, and room temperature after 1000 h, however reference cell efficiency...
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...
Microstructure-performance relationships in gas tungsten arc welded Hastelloy X nickel-based superalloy, Article Materials Science and Engineering A ; Volume 793 , 2020 ; Kolagar, A. M ; Pouranvari, M ; Sharif University of Technology
Elsevier Ltd 2020
This study aims at understanding the metallurgical and mechanical response of Hastelloy X nickel-based superalloy to the thermal cycle of gas tungsten arc welding (GTAW), post welding solution treatment (ST), and aging. In the as-weld condition, the weldment was characterized by the formation of the M6C carbide, sigma phase, and micro-solidification cracks in the interdendritic zones of the weld metal, and constitutional liquation of M6C carbide in the heat-affected zone. It is demonstrated that neither the weld metal nor the heat-affected zone could adversely affect mechanical properties of the welded joint in as-weld condition. However, to alleviate the microstructural heterogeneity,...
A new Mumm-type rearrangement with dithiocarbamates via isocyanide-based multicomponent reaction under ultrasound irradiation: synthesis of polysubstituted pyrrolidine compounds, Article New Journal of Chemistry ; Volume 44, Issue 23 , May , 2020 , Pages 9699-9702 ; Goudarzi, M ; Chamani, F ; Mohammadzadeh Dezag, H ; Sharif University of Technology
Royal Society of Chemistry 2020
A novel and efficient multicomponent reaction for the synthesis of polysubstituted pyrrolidine derivatives is described under catalyst-free conditions using ultrasonic irradiation. The reactions were performed via a one-pot four-component condensation of secondary amines, carbon disulfide, isocyanides, and gem-dicyano olefins at room temperature to afford polysubstituted pyrrolidines diastereoselectively in 56-96% yields. This is the first report of a Mumm-type rearrangement with dithiocarbamates followed by intramolecular cyclization, which leads to the preparation of the key structure of pyrrolidine. This journal is © The Royal Society of Chemistry and the Centre National de la Recherche...
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...
Sequential RTV/(TiO2/SiO2) nanocomposite deposition for suppressing the leakage current in silicone rubber insulators, Article Applied Physics A: Materials Science and Processing ; Volume 126, Issue 5 , 2020 ; Mohammadi, M ; Shayegani Akmal, A. A ; Samadpour, M ; dehghani, M ; Parvazian, E ; Sharif University of Technology
The sequential deposition method is introduced for suppressing the leakage current in silicone rubber insulators. Room temperature vulcanizing silicone and TiO2/silica nanocomposites are sequentially deposited on silicone insulators surface. TEM results showed that TiO2 nanoparticles size is about 20–30 nm, and the structural study revealed their anatase crystalline structure. Silica nanoparticles are deposited on the surface of insulators by spray deposition. The contact angle was enhanced from 104° to 149° after nanoparticles deposition, which confirms the hydrophobicity improvement. Results show that leakage current for nanocomposite samples in a contaminated environment reduced to about...
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...
Near-room-temperature spin caloritronics in a magnetized and defective zigzag MoS2 nanoribbon, Article Journal of Computational Electronics ; Volume 19, Issue 1 , 2020 , Pages 137-146 ; Fathipour, M ; Faez, R ; Darvish, G ; Sharif University of Technology
Using a tight-binding approach and first-principles calculations combined with the nonequilibrium Green’s function method, the thermal spin transport in a zigzag molybdenum disulfide (MoS 2) nanoribbon in the proximity of a ferromagnetic insulator that induces a local exchange magnetic field in the center of the nanoribbon is investigated. It is found that a pure spin current and perfect spin Seebeck effect with zero charge current can be generated by applying a thermal gradient and local exchange magnetic field without a bias voltage near room temperature. Furthermore, it is shown that this nanoscale device can act as a spin Seebeck diode for the control of thermal and spin information 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...
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
Ballistic molecular transport through two-dimensional channels, Article Nature ; Volume 558 , 20 June , 2018 , Pages 420-423 ; 00280836 (ISSN) ; Geim, A. K ; Janardanan, A ; Rooney, A. P ; Esfandiar, A ; Hu, S ; Dar, S. A ; Grigorieva, I. V ; Haigh, S. J ; Wang, F. C ; Radha, B ; Sharif University of Technology
Nature Publishing Group 2018
Gas permeation through nanoscale pores is ubiquitous in nature and has an important role in many technologies 1,2 . Because the pore size is typically smaller than the mean free path of gas molecules, the flow of the gas molecules is conventionally described by Knudsen theory, which assumes diffuse reflection (random-angle scattering) at confining walls 3-7 . This assumption holds surprisingly well in experiments, with only a few cases of partially specular (mirror-like) reflection known 5,8-11 . Here we report gas transport through ångström-scale channels with atomically flat walls 12,13 and show that surface scattering can be either diffuse or specular, depending on the fine details of the...
Synthesis of functionalized benzothiadiazine 1,1-dioxide derivatives via intramolecular C–H activation reactions of trichloroacetamidine and benzenesulfonyl chloride, Article Tetrahedron Letters ; Volume 59, Issue 21 , 23 May , 2018 , Pages 2054-2056 ; 00404039 (ISSN) ; Rezaee, E ; Jahani, M ; Tabatabai, S. A ; Sharif University of Technology
Elsevier Ltd 2018
The synthesis of functionalized benzothiadiazine 1,1-dioxide derivatives was achieved through a novel three-component intramolecular C–H activation reaction of trichloroacetonitrile, benzenesulfonyl chloride, and various primary amines. This reaction was performed in the presence of catalytic copper(I) and L-proline as the ligand in tetrahydrofuran at room temperature. © 2018 Elsevier Ltd
Palladium immobilized onto functionalized magnetic nanoparticles as robust catalysts for amination and room-temperature ullmann homocoupling of aryl halides: a walk around the C−F bond activation, Article Asian Journal of Organic Chemistry ; Volume 7, Issue 4 , 2018 , Pages 802-809 ; 21935807 (ISSN) ; Pourkaveh, R ; Karimi, A ; Ayati, E ; Sharif University of Technology
Wiley-VCH Verlag 2018
The first example of a heterogeneous catalytically active system for Buchwald–Hartwig and Ullmann homocoupling of unactivated aryl halides (fluorobenzene) is presented. The novel magnetic heterogeneous palladium catalyst was synthesized by immobilization of palladium ions onto an aminopyridine-functionalized Fe3O4. The catalyst was fully characterized by FTIR spectroscopy, temperature-programmed reduction, thermogravimetric analysis, CHN elemental analysis, transmission electron microscopy, field-emission scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, and atomic absorption spectroscopy. By using this catalyst system, various types of primary and...
Cobalt-copper ferrite nanoparticles catalyzed click reaction at room-temperature: green access to 1,2,3-triazole derivatives, Article ChemistrySelect ; Volume 3, Issue 9 , 2018 , Pages 2586-2593 ; 23656549 (ISSN) ; Pourkaveh, R ; Ahangarpour, M ; Sharif University of Technology
A typical Cobalt-Copper ferrite nanoparticles (CoCuFe2O4) was used as a catalyst for one-pot [3+2] cycloaddition of alkyl azides with alkynes at room temperature in green media. These nanoparticles were synthesized by using co-precipitation method and were fully characterized by physiochemical technique. By this catalyst system, various types of alkyl halides were coupled with alkynes efficiently to furnish 1,2,3 triazoles in excellent yields within short reaction time. The requirement on energy and time for the Click reaction extremely minimized in this method compared to previously reported reactions as an inevitable trend in development of green chemistry. Using green solvent, inexpensive...
Efficient synthesis of propargylamines in aqueous media catalyzed by au nanoparticles under ambient temperature, Article ChemistrySelect ; Volume 3, Issue 7 , 2018 , Pages 2053-2058 ; 23656549 (ISSN) ; Pourkaveh, R ; Sharif University of Technology
An eco-friendly gold-based catalyst supported on proline decorated montmorillonite was synthesized. The catalyst was characterized by combination of Fourier-transform infrared spectroscopy (FT-IR), Field Emission Scanning Electron Microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Brunauer–Emmett Teller (BET) surface area analysis, Ultraviolet–visible spectroscopy (UV-Vis), Energy-dispersive X-ray spectroscopy (EDX), thermo gravimetric analysis (TGA) and atomic absorption spectroscopy (AAS) techniques. The synthesized catalyst was found to be a highly efficient heterogeneous nanocatalyst for multi component A3 coupling reaction of aldehyde, amine and alkyne...
Long-term stability of dye-sensitized solar cells using a facile gel polymer electrolyte, Article New Journal of Chemistry ; Volume 42, Issue 16 , 2018 , Pages 13256-13262 ; 11440546 (ISSN) ; Asgari Moghaddam, H ; Nouri, E ; Mohammadi, M. R ; Sharif University of Technology
Royal Society of Chemistry 2018
Herein, we demonstrate a facile low temperature approach to prepare a gel polymer electrolyte (GPE) based on the triiodide/iodide redox couple in a quasi-solid-state dye-sensitized solar cell (DSSC). Only one polymeric agent (i.e., hydroxypropyl cellulose (HPC)) is used for the preparation of a non-volatile GPE system for the standard liquid electrolyte containing 1-methyl-3-propylimidazolium iodide (MPII). The prepared GPE completely penetrates into a TiO2 photoanode at room temperature due to the uniform distribution of Ti, Ru and I elements in the cross-section of the electrode, forming an interpenetrating GPE/TiO2 network to access all dye molecules. The GPE with the optimum HPC : MPII...
Inverted perovskite solar cells based on lithium-functionalized graphene oxide as an electron-transporting layer, Article Chemical Communications ; Volume 53, Issue 10 , 2017 , Pages 1630-1633 ; 13597345 (ISSN) ; Mohammadi, M. R ; Lianos, P ; Sharif University of Technology
Royal Society of Chemistry 2017
Perovskite solar cells with an inverted p-i-n architecture were constructed under ambient conditions by employing materials of lower cost than standard cells. Thus, graphene oxide was used as a hole transporting material and Li-modified graphene oxide as an electron transporting material, while Al was used as a counter electrode. A maximum solar conversion efficiency of 10.2% was achieved by adding a Ti-based sol on the top of the Li-modified graphene oxide layer. © The Royal Society of Chemistry
Catalyst-Free and Green Synthesis of Some Novel Benzamide Derivatives, Article Journal of Heterocyclic Chemistry ; Volume 52, Issue 6 , November , 2015 , Pages 1848-1857 ; 0022152X (ISSN) ; Rostami, M ; Mirkhani, V ; Moghadam, M ; Mohammadpoor Baltork, I ; Tangestaninejad, S ; Jamali Moghadam, A ; Kia, R ; Sharif University of Technology
In the present work, a simple, green, rapid, and catalyst-free procedure for the synthesis of benzamide derivatives by ring opening of azlactones with diamines such as ethylene diamine and 1,3-propylenediamine is described. The present method offers several advantages such as short reaction times, easy work-up, and mild reaction conditions in the absence of catalyst and any toxic solvent and material. In addition, the structure obtained by X-ray crystallography was compared with the theoretical results obtained by density functional theory using the B3LYP functional and cc-pVDZ basis sets
Ag3PO4/BiPO4 p-n heterojunction nanocomposite prepared in room-temperature ionic liquid medium with improved photocatalytic activity, Article Materials Science in Semiconductor Processing ; Volume 39 , 2015 , Pages 506-514 ; 13698001 (ISSN) ; Rahimi, E ; Gholami, M. R ; Sharif University of Technology
Elsevier Ltd 2015
Abstract A visible-light-active Ag3PO4/BiPO4 nanocomposite with a p-n heterojunction structure was fabricated via a co-precipitation hydrothermal process using 2-hydroxylethylammonium formate (RTIL) as a room-temperature ionic liquid. The resulting catalysts were characterized by various techniques. The photocatalytic activity of the photocatalysts was evaluated by the photodegradation of phthalocyanine Reactive Blue 21 (RB21) under both visible and UV light irradiations. The results reveal that the heterojunction composite prepared in RTIL noticeably exhibited an improvement in both efficiency and rate of RB21 photodegradation in comparison with pure Ag3PO4 and BiPO4. The enhanced...