Search for: metal-nanoparticle
Total 192 records
Synthesis of pseudopolyrotaxanes-coated superparamagnetic Iron oxide nanoparticles as new MRI contrast agent, Article Colloids and Surfaces B: Biointerfaces ; Volume 103 , March , 2013 , Pages 652-657 ; 09277765 (ISSN) ; Panahifar, A ; Adeli, M ; Amiri, H ; Lascialfari, A ; Orsini, F ; Doschak, M. R ; Mahmoudi, M ; Sharif University of Technology
Superparamagnetic Iron Oxide Nanoparticles (SPIONs) were synthesized and coated with pseudopolyrotaxanes (PPRs) and proposed as a novel hybrid nanostructure for medical imaging and drug delivery. PPRs were prepared by addition of α-cyclodextrin rings to functionalized polyethylene glycol (PEG) chain with hydrophobic triazine end-groups. Non-covalent interactions between SPIONs and PPRs led to the assembly of SPIONs@PRs hybrid nanomaterials. Measurements of the 1H Nuclear Magnetic Resonance (NMR) relaxation times T1 and T2 allowed us to determine the NMR dispersion profiles. Comparison between our SPIONs@PRs hybrid nano-compound and the commercial SPION compound, Endorem®, showed a higher...
Fe 50Co 50 nanoparticles via self-propagating high-temperature synthesis during milling, Article Powder Technology ; Volume 208, Issue 3 , 2011 , Pages 623-627 ; 00325910 (ISSN) ; Yourdkhani, A ; Koohestani, H ; Sadrnezhaad, S. K ; Asmatulu, R ; Sharif University of Technology
Self-propagating exothermic reactions during mechanical milling of FeCl 3/CoCl 2 mixture together with sodium seeds resulted in formation of Fe 50Co 50 nanoparticles. Highly exothermic reactions resulted in temperature raise and formation of Fe 50Co 50 phase within the first 5min; however Fe 50Co 50 single-phase was obtained after 30min of milling. The products were characterized by XRD, SEM, EDS, TEM and VSM. Obtained results showed that both milling time and NaCl salt matrix affected the size, morphology, microstructure and magnetic properties of the produced particles
Sol-gel-based silver nanoparticles-doped silica - Polydiphenylamine nanocomposite for micro-solid-phase extraction, Article Analytica Chimica Acta ; Volume 886 , July , 2015 , Pages 56-65 ; 00032670 (ISSN) ; Banihashemi, S ; Sharif University of Technology
A nanocomposite of silica-polydiphenylamine doped with silver nanoparticles (Ag-SiO
2-PDPA) was successfully synthesized by the sol-gel process. For its preparation, PDPA was mixed with butanethiol capped Ag nanoparticles (NPs) and added to the silica sol solution. The Ag NPs were stabilized as a result of their adsorption on the SiO 2 spheres. The surface characteristic of nanocomposite was investigated using scanning electron microscopy (SEM). In this work the Ag-SiO 2-PDPA nanocomposite was employed as an efficient sorbent for micro-solid-phase extraction (μ-SPE) of some selected pesticides. An amount of 15 mg of the prepared sorbent was used to extract and...
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...
A colorimetric sensor array for detection and discrimination of biothiols based on aggregation of gold nanoparticles, Article Analytica Chimica Acta ; Volume 882 , July , 2015 , Pages 58-67 ; 00032670 (ISSN) ; Hormozi-Nezhad, M.R ; Mahmoudi, M ; Sharif University of Technology
Developments of sensitive, rapid, and cheap systems for identification of a wide range of biomolecules have been recognized as a critical need in the biology field. Here, we introduce a simple colorimetric sensor array for detection of biological thiols, based on aggregation of three types of surface engineered gold nanoparticles (AuNPs). The low-molecular-weight biological thiols show high affinity to the surface of AuNPs; this causes replacement of AuNPs' shells with thiol containing target molecules leading to the aggregation of the AuNPs through intermolecular electrostatic interaction or hydrogen-bonding. As a result of the predetermined aggregation, color and UV-vis spectra of AuNPs...
The effect of Au/Ag ratios on surface composition and optical properties of co-sputtered alloy nanoparticles in Au-Ag:SiO2 thin films, Article Journal of Alloys and Compounds ; Volume 486, Issue 1-2 , 2009 , Pages 22-28 ; 09258388 (ISSN) ; Akhavan, O ; Zaker Moshfegh, A. R ; Sharif University of Technology
Gold-silver alloy nanoparticles with various Au concentrations in sputtered SiO2 thin films were synthesized by using RF reactive magnetron co-sputtering and then heat-treated in reducing Ar + H2 atmosphere at different temperatures. The UV-visible absorption spectra of the bimetallic systems confirmed the formation of alloy nanoparticles. The optical absorption of the Au-Ag alloy nanoparticles exhibited only one plasmon resonance absorption peak located at 450 nm between the absorption bands of pure Au and Ag nanoparticles at 400 and 520 nm, respectively, for the thin films annealed at 800 °C. The maximum absorption wavelength of the surface plasmon band showed a red shift with increasing...
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...
Well-designed Ag/ZnO/3D graphene structure for dye removal: Adsorption, photocatalysis and physical separation capabilities, Article Journal of Colloid and Interface Science ; Volume 537 , 2019 , Pages 66-78 ; 00219797 (ISSN) ; Samadi, M ; Asadian, E ; Zhou, Y ; Dong, C ; Zhang, J ; Moshfegh Zaker, A. R ; Sharif University of Technology
Academic Press Inc 2019
In this research, adsorption and photocatalytic degradation process were utilized to remove organic dye from wastewater. To accomplish that, a newly-designed ternary nanostructure based on Ag nanoparticles/ZnO nanorods/three-dimensional graphene network (Ag NPs/ZnO NRs/3DG) was prepared using a combined hydrothermal-photodeposition method. The three-dimensional structure of graphene hydrogel as a support for growth of ZnO nanorods was characterized using field emission scanning electron microscopy (FESEM). In addition, diameter of silver nanoparticles grown on the ZnO nanorods with the average aspect ratio of 5 was determined in the range of 30–80 nm by using transmission electron microscopy...
Design and fabrication of an electrochemical aptasensor using Au nanoparticles/carbon nanoparticles/cellulose nanofibers nanocomposite for rapid and sensitive detection of Staphylococcus aureus, Article Bioelectrochemistry ; Volume 123 , 2018 , Pages 70-76 ; 15675394 (ISSN) ; Shahrokhian, S ; Sharif University of Technology
Elsevier B.V 2018
Since that pathogenic bacteria are major threats to human health, this paper describes the fabrication of an effective and durable sensing platform based on gold nanoparticles/carbon nanoparticles/cellulose nanofibers nanocomposite (AuNPs/CNPs/CNFs) at the surface of glassy carbon electrode for sensitive and selective detection of Staphylococcus aureus (S. aureus). The AuNPs/CNPs/CNFs nanocomposite with the high surface area, excellent conductivity, and good biocompatibility was used for self-assembled of the thiolated specific S. aureus aptamer as a sensing element. The surface morphology of AuNPs/CNPs/CNFs nanocomposite was characterized with field emission scanning electron microscopy...
An in vitro study of bare and poly(ethylene glycol)-co-fumarate-coated superparamagnetic iron oxide nanoparticles: A new toxicity identification procedure, Article Nanotechnology ; Volume 20, Issue 22 , 2009 ; 09574484 (ISSN) ; Simchi, A ; Imani, M ; Milani, A. S ; Stroeve, P ; Sharif University of Technology
As the use of superparamagnetic iron oxide nanoparticles (SPION) in biomedical applications increases (e.g. for targeting drug delivery and imaging), patients are likely to be exposed to products containing SPION. Despite their high biomedical importance, toxicity data for SPION are limited to date. The aim of this study is to investigate the cytotoxicity of SPION and its ability to change cell medium components. Bare and poly(ethylene glycol)-co-fumarate (PEGF)-coated SPION with narrow size distributions were synthesized. The particles were prepared by co-precipitation using ferric and ferrous salts with a molar Fe3+/Fe2+ ratio of 2. Dulbecco's modified Eagle's medium (DMEM) and primary...
Lasting antibacterial activities of Ag-TiO2/Ag/a-TiO2 nanocomposite thin film photocatalysts under solar light irradiation, Article Journal of Colloid and Interface Science ; Volume 336, Issue 1 , 2009 , Pages 117-124 ; 00219797 (ISSN) ; Sharif University of Technology
Photodegradation of Escherichia coli bacteria in presence of Ag-TiO2/Ag/a-TiO2 nanocomposite film with an effective storage of silver nanoparticles was investigated in the visible and the solar light irradiations. The nanocomposite film was synthesized by sol-gel deposition of 30 nm Ag-TiO2 layer on ∼200 nm anatase(a-)TiO2 film previously doped by silver nanoparticles. Both Ag/a-TiO2 and Ag-TiO2/Ag/a-TiO2 films were transparent with a SPR absorption band at 412 nm. Depth profile X-ray photoelectron spectroscopy showed metallic silver nanoparticles with diameter of 30 nm and fcc crystalline structure were self-accumulated on the film surface at depth of 5 nm of the TiO2 layer and also at the...
Ultrafast and simultaneous removal of anionic and cationic dyes by nanodiamond/UiO-66 hybrid nanocomposite, Article Chemosphere ; Volume 247 , May , 2020 ; Neshastehgar, M ; Shojaei, A ; Ghashghaeinejad, H ; Sharif University of Technology
Elsevier Ltd 2020
In this research, UiO-66 and its composite nanoparticles with thermally oxidized nanodiamond (OND) were synthesized via a simple solvothermal method and utilized as solid adsorbent for the removal of anionic methyl red (MR) dye and cationic malachite green (MG) dye from contaminated water. The synthesized adsorbents were analyzed by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), thermogravimetric analysis (TGA), N2 adsorption–desorption, and zeta potential analyzer. The influences of various factors such as initial concentrations of the dyes, adsorption process time, solution pH, solution temperature and ionic...