Search for: metal-nanoparticle
0.009 seconds
Total 192 records

    The effect of protein corona on doxorubicin release from the magnetic mesoporous silica nanoparticles with polyethylene glycol coating

    , Article Journal of Nanoparticle Research ; Volume 17, Issue 4 , April , 2015 ; 13880764 (ISSN) Pourjavadi, A ; Tehrani, Z. M ; Mahmoudi, N ; Sharif University of Technology
    Kluwer Academic Publishers  2015
    In the present work, biocompatible superparamagnetic iron oxide nanoparticles coated by mesoporous silica were used as drug nanocarriers for doxorubicin (Dox; an anticancer drug) delivery. In biological media, the interaction of protein corona layer with the surface of nanoparticles is inevitable. For this reason, we studied the effect of protein corona on drug release from magnetic mesoporous silica nanoparticles (MMSNs) in human plasma medium. Besides, we used hydrophilic and biocompatible polymer, polyethylene glycol (PEG), to decrease protein corona effects. The results showed the increased Dox release from PEGylated MMSNs compared with bare MMSNs. This result indicated that the coating... 

    Colourimetric-based method for the diagnosis of spinal muscular atrophy using gold nanoprobes

    , Article IET Nanobiotechnology ; Volume 9, Issue 1 , Feb , 2015 , Pages 5-10 ; 17518741 (ISSN) Ahmadpour Yazdi, H ; Hormozi Nezhad, M. R ; Abadi, A. R ; Sanati, M. H ; Kazemi, B ; Sharif University of Technology
    Institution of Engineering and Technology  2015
    Although numerous molecular methods for spinal muscular atrophy (SMA) detection have been exploited, most of hem are laborious, time consuming and costly. Recently, gold nanoparticles (AuNPs) have attracted attention in the field of colourimetric bioanalysis, because AuNP aggregation can be tracked with the naked eye as well as ultraviolet-visible (UV-vis) peak analysis. Here, based on a non-cross linking platform, a colourimetric-based method was used to evaluate the capability of thiolated oligo-AuNPs (Au nanoprobes) to distinguish between normal individuals, carriers and those with SMA. In this platform, removal of the repulsive force of the Au nanoprobes using high salt concentration... 

    Fabrication and characterization and biosensor application of gold nanoparticles on the carbon nanotubes

    , Article Applied Surface Science ; Volume 355 , November , 2015 , Pages 1175-1179 ; 01694332 (ISSN) Ghodselahi, T ; Aghababaie, N ; Mobasheri, H ; Zand Salimi, K ; Akbarzadeh Pasha, M ; Vesaghi, M. A ; Sharif University of Technology
    Elsevier  2015
    Gold nanoparticles (Au NPs) were synthesized by co-deposition of RF-sputtering and RF-PECVD from acetylene gas and Au target on the carbon nanotubes (CNTs). The CNTs were prepared by thermal chemical vapor deposition (TCVD) and Pd nanoparticles catalyst. TEM image shows that high-density and uniform distribution of Au NPs were grown on the CNTs. XRD analysis indicates that Au NPs have fcc crystal structure and CNTs have a good graphite structure. Raman spectroscopy results suggest that our sample includes double-walled CNTs. It is resulted that intensity of D-band reduces and G-band intensity raises and radial breathing mode (RBM) is changed by immobilizing of Au NPs on the CNTs. Raman... 

    Protein corona composition of gold nanoparticles/nanorods affects amyloid beta fibrillation process

    , Article Nanoscale ; Volume 7, Issue 11 , Feb , 2015 , Pages 5004-5013 ; 20403364 (ISSN) Mirsadeghi, S ; Dinarvand, R ; Ghahremani, M. H ; Hormozi-Nezhad, M. R ; Mahmoudi, Z ; Hajipour, M. J ; Atyabi, F ; Ghavami, M ; Mahmoudi, M ; Sharif University of Technology
    Royal Society of Chemistry  2015
    Protein fibrillation process (e.g., from amyloid beta (Aβ) and α-synuclein) is the main cause of several catastrophic neurodegenerative diseases such as Alzheimer's and Parkinson diseases. During the past few decades, nanoparticles (NPs) were recognized as one of the most promising tools for inhibiting the progress of the disease by controlling the fibrillation kinetic process; for instance, gold NPs have a strong capability to inhibit Aβ fibrillations. It is now well understood that a layer of biomolecules would cover the surface of NPs (so called "protein corona") upon the interaction of NPs with protein sources. Due to the fact that the biological species (e.g., cells and amyloidal... 

    Application of the combined neuro-computing, fuzzy logic and swarm intelligence for optimization of compocast nanocomposites

    , Article Journal of Composite Materials ; Volume 49, Issue 13 , 2015 , Pages 1653-1663 ; 00219983 (ISSN) Tofigh, A. A ; Rahimipour, M. R ; Shabani, M. O ; Davami, P ; Sharif University of Technology
    SAGE Publications Ltd  2015
    In the last few years, an increasing attention has been paid to the issues of saving energy and reducing the manufacturing costs in the transport industry which necessitates further efforts to replace traditional materials like steel with lightweight materials such as plastics, aluminum, magnesium, and composites. Metal matrix nanocomposites have turned into an established material in today's industry with an ongoing expansion in their field of applications. In this study, the formation of nanoparticle-aluminum metal matrix composites is described by compocast processing from nanoparticle Al2O3 and the A356 aluminum alloy. In order to optimize the processing parameters, a novel approach is... 

    Reactive friction stir processing of AA 5052-TiO2 nanocomposite: Process-microstructure-mechanical characteristics

    , Article Materials Science and Technology (United Kingdom) ; Volume 31, Issue 4 , 2015 , Pages 426-435 ; 02670836 (ISSN) Khodabakhshi, F ; Simchi, A ; Kokabi, A. H ; Sadeghahmadi, M ; Gerlich, A. P ; Sharif University of Technology
    Maney Publishing  2015
    Friction stir processing (FSP) is a solid state route with a capacity of preparing fine grained nanocomposites from metal sheets. In this work, we employed this process to finely distribute TiO2 nanoparticles throughout an Al-Mg alloy, aiming to enhance mechanical properties. Titanium dioxide particles (30 nm) were preplaced into grooves machined in the middle of the aluminium alloy sheet and multipass FSP was afforded. This process refined the grain structure of the aluminium alloy, distributed the hard nanoparticles in the matrix and promoted solid state chemical reactions at the interfaces of the metal/ceramic particles. Detailed optical and electron microscopic studies showed that the... 

    ZnFe2O4 nanoparticles as radiosensitizers in radiotherapy of human prostate cancer cells

    , Article Materials Science and Engineering C ; Volume 46 , January , 2015 , Pages 394-399 ; 09284931 (ISSN) Meidanchi, A ; Akhavan, O ; Khoei, S ; Shokri, A. A ; Hajikarimi, Z ; Khansari, N ; Sharif University of Technology
    Elsevier Ltd  2015
    Nanoparticles of high-Z elements exhibit stronger photoelectric effects than soft tissues under gamma irradiation. Hence, they can be used as effective radiosensitizers for increasing the efficiency of current radiotherapy. In this work, superparamagnetic zinc ferrite spinel (ZnFe2O4) nanoparticles were synthesized by a hydrothermal reaction method and used as radiosensitizers in cancer therapy. The magnetic nanoparticles showed fast separation from solutions (e.g., ~ 1 min for 2 mg mL- 1 of the nanoparticles in ethanol) by applying an external magnetic field (~ 1 T). The ZnFe2O4 nanoparticles were applied in an in vitro radiotherapy of lymph node carcinoma of prostate cells (as high... 

    Surface free energy of platinum nanoparticles at zero pressure: A molecular dynamic study

    , Article Solid State Communications ; Volume 150, Issue 5-6 , February , 2010 , Pages 254-257 ; 00381098 (ISSN) Akbarzadeh, H ; Abroshan, H ; Parsafar, G. A ; Sharif University of Technology
    Metallic nanoparticles are interesting because of their use in catalysis and sensors. The surface energy of the FCC platinum nanoparticles are investigated via molecular dynamics simulation using Quantum Sutton-Chen (QSC) potential. We have calculated the Gibbs free energy for the FCC platinum bulk and also for its nanoparticle. All calculations have been carried out at zero pressure. We have used the thermodynamic integration method to obtain the Gibbs free energy. The total Gibbs free energy is taken as the sum of its central bulk and its surface free energy. We have calculated the free energy of a platinum nanoparticle as a function of temperature  

    Copper nanoparticles supported on CeO2 as an efficient catalyst for click reactions of azides with alkynes

    , Article Catalysis Communications ; Volume 85 , 2016 , Pages 13-16 ; 15667367 (ISSN) Amini, M ; Hassandoost, R ; Bagherzadeh, M ; Gautam, S ; Chae, K. H ; Sharif University of Technology
    Elsevier  2016
    Readily prepared copper nanoparticles supported on CeO2 have been found to effectively catalyse the 1,3-dipolar cycloaddition (CuAAC) of a variety terminal alkynes and organic azides generated in situ from sodium azide and different organic halides furnishing the corresponding 1,2,3-triazoles in excellent yields. Cu nanoparticles supported on CeO2 have been characterized by X-ray diffraction analysis, energy dispersive X-ray analysis, scanning electron microscope and transmission electron microscope. The salient features of the present protocol are shorter reaction time, mild reaction conditions, reusability of the catalyst, and applicability to a wide range of substrates. © 2016 Elsevier... 

    α-Arylation of oxindoles using recyclable metal oxide ferrite nanoparticles: Comparison between the catalytic activities of nickel, cobalt and copper ferrite nanoparticles

    , Article Catalysis Communications ; Volume 75 , 2016 , Pages 37-41 ; 15667367 (ISSN) Matloubi Moghaddam, F ; Tavakoli, G ; Latifi, F ; Saeednia, B ; Sharif University of Technology
    Three different spinel metal oxide catalytic systems including NiFe2O4, CuFe2O4 and CoFe2O4 were synthesized using co-precipitation technique and their catalytic activities were compared to each other in α-arylation of oxindole derivatives under the optimized reaction conditions. Both nickel ferrite and copper ferrite magnetic nanoparticles show approximately the same behavior in these reactions but cobalt ferrite ones indicate slightly different properties and were not as good as the other two catalysts. These superparamagnetic catalysts allowed that α-arylation of different types of oxindoles will occur in high yields under mild conditions and at very short times  

    Supercritical synthesis of a magnetite-reduced graphene oxide hybrid with enhanced adsorption properties toward cobalt & strontium ions

    , Article RSC Advances ; Volume 6, Issue 17 , 2016 , Pages 13898-13913 ; 20462069 (ISSN) Tayyebi, A ; Outokesh, M ; Sharif University of Technology
    Royal Society of Chemistry  2016
    The current study presents a supercritical synthesis of magnetite-reduced graphene oxide (M-RGO) in methanol media, in which Fe3O4 nanoparticles are simultaneously formed, surface modified and decorated on the surface of the reduced graphene oxide. Simulations using density functional theory, which were performed using the M06-2x/cc-pVDZ level of theory, indicate that upon adsorption of a Fe3O4 cluster on the graphene, the overall charge on the graphene surface becomes about -0.0236e, indicating charge transfer from the Fe3O4 cluster to the graphene surface. Instrumental and chemical analyses exhibited the formation of strong bonds between Fe3O4 and graphene, through C-O-Fe and C-Fe bridges.... 

    Characterisation of nanocrystalline sulfated titania modified with transition metals and aluminum as solid acids for esterification

    , Article Progress in Reaction Kinetics and Mechanism ; Volume 41, Issue 1 , 2016 , Pages 57-66 ; 14686783 (ISSN) Rahman Setayesh, S ; Abolhasani, E ; Ghasemi, S ; Sharif University of Technology
    Science Reviews 2000 Ltd  2016
    TiO2, transition metal (Cr, Mn, Fe, Co, Ni, Cu, and Zn)- and aluminum-doped TiO2 nanoparticles were prepared by the sol-gel technique. The sulfated catalysts were prepared by the impregnation method with H2SO4 solution. The catalysts were characterised by X-ray diffraction (XRD), BET surface area measurement, diffuse reflectance spectroscopy (DRS), and Fourier transform infrared (FTIR) techniques. The sulfate content of the metal-incorporated samples was considerably higher than for SO4 2-/TiO2. The metal doping brought about a considerable reduction in the extent of sulfate loss from the catalyst surface due to the wide dispersion on the surface. The SO4 2-/TiO2 and SO4 2-/M/TiO2... 

    Plasmonic effects of infiltrated silver nanoparticles inside TiO2 film: Enhanced photovoltaic performance in DSSCs

    , Article Journal of the American Ceramic Society ; Volume 99, Issue 1 , 2016 , Pages 167-173 ; 00027820 (ISSN) Andaji Garmaroudi, Z ; Mohammadi, M. R ; Sharif University of Technology
    Blackwell Publishing Inc 
    The plasmonic effects of infiltrated silver (Ag) nanoparticles, with different contents, inside a nanostructured TiO2 film on the photovoltaic performance of dye-sensitized solar cells (DSSCs) are explored. The synthesized Ag nanoparticles are immobilized onto deposited TiO2 nanoparticles by a new strategy using 3-mercaptopropionic acid (MPA), a bifunctional linker molecule. Transmission electron microscope (TEM) images show that monodispersed Ag and polydispersed TiO2 nanoparticles have an average diameter of 12 ± 3 nm and 5 ± 1 nm, respectively. Moreover, Fourier transform infrared spectroscopy (FTIR) analysis reveals that Ag nanoparticles were successfully functionalized and capped with... 

    The effect of sol-gel surface modified silver nanoparticles on the protective properties of the epoxy coating

    , Article RSC Advances ; Volume 6, Issue 23 , 2016 , Pages 18996-19006 ; 20462069 (ISSN) Ghazizadeh, A ; Haddadi, S. A ; Mahdavian, M ; Sharif University of Technology
    Royal Society of Chemistry  2016
    In this study, the effect of surface modified silver nanoparticles on the corrosion protection of an epoxy coating on mild steel was studied. An organosilane (3-methoxy silyl propyl metacrylate) was used as a surface modifier to increase the dispersability of the inorganic nanoparticles in the organic epoxy coating matrix. Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) were used to characterize the surface modified nanoparticles. Differential scanning colorimetry (DSC) was employed to study the effects of modified and unmodified nano-silver on the curing heat and glass transition temperature of the epoxy coatings. Salt spray and electrochemical impedance... 

    Microstructure, mechanical analysis and optimal selection of 7075 aluminum alloy based composite reinforced with alumina nanoparticles

    , Article Materials Chemistry and Physics ; Volume 178 , 2016 , Pages 119-127 ; 02540584 (ISSN) Ezatpour, H. R ; Torabi Parizi, M ; Sajjadi, S. A ; Ebrahimi, G. R ; Chaichi, A ; Sharif University of Technology
    Elsevier Ltd  2016
    Aluminum metal-matrix nanocomposites (AMMNCs) fabricated by conventional stir-casting process usually show high porosity and poor distribution of nanoparticles within the matrix. In the current study, for the improvement of nanoparticles distribution in the aluminum matrix and enhancement of the mechanical properties, a mixture of Al/nano-Al2O3 powders were injected by pure argon gas into the molten 7075 aluminum alloy and this mixture was extruded at high temperature. Mechanical behavior of the final product was investigated by tensile and compression tests, hardness measurements, Scanning Electron Microscopy (SEM), High Resolution Transmission Electron Microscopy (HRTEM) and Optical... 

    Gold nanoparticles anchored onto the magnetic poly(ionic-liquid) polymer as robust and recoverable catalyst for reduction of Nitroarenes

    , Article Applied Organometallic Chemistry ; Volume 31, Issue 12 , 2017 ; 02682605 (ISSN) Matloubi Moghaddam, F ; Ayati, S. E ; Firouzi, H. R ; Hosseini, S. H ; Pourjavadi, A ; Sharif University of Technology
    Gold nanoparticles supported on poly ionic-liquid magnetic nanoparticles (MNP@PIL@Au) were synthesized by reduction of HAuCl4 with sodium borohydride. The synthesized catalyst was characterized using by AAS, TEM, FT-IR, EDS, TGA and XRD techniques. The performance of the synthesized catalyst was investigated in the reduction of nitroarenes with NaBH4. The reaction was carried out for various nitroarenes in water and mild conditions with high yields. The catalyst selectivity for the reduction of nitro group in the presences of other functional groups such as halides and alkynes was fairly well. The recycling of the catalyst was done 8 times without any significant loss of its catalytic... 

    Reactive friction-stir processing of nanocomposites: effects of thermal history on microstructure–mechanical property relationships

    , Article Materials Science and Technology (United Kingdom) ; Volume 33, Issue 15 , 2017 , Pages 1776-1789 ; 02670836 (ISSN) Khodabakhshi, F ; Kokabi, A. H ; Simchi, A ; Sharif University of Technology
    The effects of thermal history on the microstructure and mechanical properties of a friction-stir-processed Al–Mg–TiO2 (3 vol.-%, 20 nm) nanocomposite were studied. It is shown that, with increases in peak temperature, a more uniform distribution of nanoparticles in the metal matrix, and a refined grain structure, are attained. Transmission electron microscopy indicated that the mechanism of grain refinement is influenced by the hard inclusions, changing from discontinuous to continuous dynamic recrystallisation. A fine-grained nanocomposite (average grain size of 3 µm) with a uniform distribution of nanoparticles is obtained after four fully-overlapping passes at 1200 rev min−1 and 100 mm... 

    Determination of parabolic trough solar collector efficiency using nanofluid:a comprehensive numerical study

    , Article Journal of Solar Energy Engineering, Transactions of the ASME ; Volume 139, Issue 5 , 2017 ; 01996231 (ISSN) Khakrah, H ; Shamloo, A ; Hannani, S. K ; Sharif University of Technology
    Due to significant reduction in fossil fuel sources, several researches have been conducted recently to explore modern sources of renewable energy. One of the major fields in the category of renewable energy harnessing devices is parabolic trough solar collector (PTC). Several parameters have effect on the overall efficiency of the PTCs. As the effect of these parameters is coupled to each other, a comprehensive investigation is necessary. In the present study, a numerical analysis is performed to examine the efficiency of PTCs via variation of several governing parameters (e.g., wind velocity magnitude, nanoparticles volume fraction, inlet temperature, and reflector's orientation). A... 

    Switchable on/off drug release from gold nanoparticles-grafted dual light- and temperature-responsive hydrogel for controlled drug delivery

    , Article Materials Science and Engineering C ; Volume 76 , 2017 , Pages 242-248 ; 09284931 (ISSN) Amoli Diva, M ; Sadighi Bonabi, R ; Pourghazi, K ; Sharif University of Technology
    Elsevier Ltd  2017
    A switchable dual light- and temperature-responsive drug carrier using gold nanoparticles (Au NPs)-grafted poly(dimethylacrylamide-co-acrylamide)/poly acrylic acid [P(DMA-co-AAm)/PAAc] hydrogel was prepared by free radical polymerization procedure using N,N-methylenebisacrylamide as cross-linker and ammonium persulfate as initiator. Initial P(DMA-co-AAm) hydrogel and uniformly-distributed stable Au NPs, prepared by reduction of hydrogen tetrachloroaureate (III) hydrate in the presence of trisodium citrate, were synthesized separately. Then, the prepared P(DMA-co-AAm) and Au NPs were added to an acrylic acid solution along with the cross-linker and initiator to prepare PAAc hydrogel within... 

    Laser-assisted triggered-drug release from silver nanoparticles-grafted dual-responsive polymer

    , Article Materials Science and Engineering C ; Volume 76 , 2017 , Pages 536-542 ; 09284931 (ISSN) Amoli Diva, M ; Sadighi Bonabi, R ; Pourghazi, K ; Sharif University of Technology
    Elsevier Ltd  2017
    Laser assisted drug release from a synthesized plain polymer composed of poly (butyl methacrylate-co-acrylamide-co-methacrylic acid) [P(BMA-co-AAm-co-MAA)] and a metallo-polymer composed of silver nanoparticles (Ag NPs) grafted plain polymer (the nanocomposite) were studied to investigate their capability to serve as drug carriers. Positive temperature dependent swelling changes were observed for both carriers and their thermal sensitivity and thermal and optical switching properties were investigated in two buffered solutions. An acidic solution with pH = 1.2 to simulate stomach body condition and a neutral solution with pH = 7.4 to simulate intestine condition. Reversible phase transition...