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    Molecular dynamics simulation of manipulation of metallic nanoclusters on stepped surfaces

    , Article Central European Journal of Physics ; Volume 9, Issue 2 , 2011 , pp 454-465 ; 1644-3608 Mahboobi, S. H ; Meghdari, A. (Ali) ; Jalili, N. (Nader) ; Amiri, F. (Farshid) ; Sharif University of Technology
    Abstract
    Molecular dynamics simulations are carried out to investigate the manipulation of metallic clusters on stepped surfaces. Five surface forms are considered in the simulations. The system parts are made of pure transition metals and Sutton-Chen many-body potential is used as interatomic potential. The conditions which are subjected to change in the tests include: materials used for particles and substrate, and surface step conditions. In addition to qualitative observations, two criteria which represent the particle deformation and substrate abrasion are utilized as evaluation tools and are computed for each case. Simulation results show the effect of the aforementioned working conditions on... 

    Molecular dynamics simulation of manipulation of metallic nanoclusters on double-layer substrates [electronic resource]

    , Article Physica E: Low-dimensional Systems and Nanostructures ; 2010, Vol. 42, No. 9, pp. 2364-2374 Mahboobi, H. (Hanif) ; Meghdari, Ali ; Jalili, Nader ; Amiri, Farshid ; Sharif University of Technology
    Abstract
    Molecular dynamics simulations are carried out to investigate the manipulation of metallic clusters on double-layer surfaces. The system parts are made of transition metals. The conditions which are subjected to change in the tests are material combinations for cluster, main substrate and lubricant layer (adlayer). In addition to qualitative observations, two criteria which represent the particle deformation and substrate abrasion are utilized as evaluation tools and are computed for each case. Obtaining this sort of knowledge is highly beneficial for further experiments in order to be able to plan the conditions and routines, which guarantee better success in the manipulation process  

    Molecular dynamics simulation of manipulation of metallic nanoclusters on stepped surfaces

    , Article Central European Journal of Physics ; Volume 9, Issue 2 , 2011 , Pages 454-465 ; 18951082 (ISSN) Mahboobi, S. H ; Meghdari, A ; Jalili, N ; Amiri, F ; Sharif University of Technology
    Abstract
    Molecular dynamics simulations are carried out to investigate the manipulation of metallic clusters on stepped surfaces. Five surface forms are considered in the simulations. The system parts are made of pure transition metals and Sutton-Chen many-body potential is used as interatomic potential. The conditions which are subjected to change in the tests include: materials used for particles and substrate, and surface step conditions. In addition to qualitative observations, two criteria which represent the particle deformation and substrate abrasion are utilized as evaluation tools and are computed for each case. Simulation results show the effect of the aforementioned working conditions on... 

    Molecular dynamic investigation of size-dependent surface energy of icosahedral copper nanoparticles at different temperature

    , Article Letters on Materials ; Volume 6, Issue 4 , 2016 , Pages 266-270 ; 22185046 (ISSN) Myasnichenko, V. S ; Razavi, M ; Outokesh, M ; Sdobnyakov, N. Y ; Starostenkov, M. D ; Sharif University of Technology
    Institute for Metals Superplasticity Problems of Russian Academy of Sciences  2016
    Abstract
    The study of the surface free energy (SFE) of metal at nanoscale is far from perfection and the obtained results are approach dependent. Despite the extensive investigations, there is still a lack of a complete model for the surface energy of metallic nanoparticles which could be able to consider effects of the particle size and shape. Most studies emphasize the size dependence of the melting characteristics, rather than considering the lattice deformation and the surface energy of nanoclusters. This research aimed at computation of SFE of copper nanoclusters depending on temperature over a wide range of sizes, containing 147 to 10179 atoms. We employed molecular dynamics simulation by using... 

    Two-dimensional atomistic simulation of metallic nanoparticles pushing

    , Article Modern Physics Letters B ; Volume 23, Issue 22 , 2009 , Pages 2695-2702 ; 02179849 (ISSN) Mahboobi, S. H ; Meghdari, A ; Jalili, N ; Amiri, F ; Sharif University of Technology
    2009
    Abstract
    Nanomanipulation as a new emerging area enables precise manipulation, interaction and control at the nanoscale. Currently, the modeling schemes are based on continuum mechanics approaches. A main consideration in the nanomanipulation process is the fact that surface attraction forces are greater than gravitational forces at the nanoscale. In other words, surface area properties dominate volume properties. Especially at the nanoscale (i.e. the manipulation of fine nanoparticles with size of about 5 nm) the physical phenomena have not been completely understood. Along this line of reasoning, the aim of this paper is to conduct an atomistic investigation of physical interaction analysis of... 

    Au and Pt nanoparticles supported on Ni promoted MoS2 as efficient catalysts for p-nitrophenol reduction

    , Article Journal of Water Process Engineering ; Volume 34 , 2020 Akbarzadeh, E ; Bahrami, F ; Gholami, M. R ; Sharif University of Technology
    Elsevier Ltd  2020
    Abstract
    In present study, an efficient method was used to synthesis Au and Pt nanoparticles on Ni modified MoS2 (MNi/MoS2 (M = Au and Pt). The morphology and structure of the prepared products were characterized using different microscopic and spectroscopic methods. The as-synthesized MNi/MoS2 nanocomposites were applied for catalytic reduction of p-nitrophenol (P-NP) in the presence of NaBH4. P-NP is one of the prevalent contaminants in wastewaters, while its corresponding aromatic amine (4-aminophenol) is a precious intermediate for manufacturing of important materials such as pharmaceuticals. The obtained catalytic results indicated that noble metal nanoparticles significantly affect catalytic... 

    Synthesis of M/CuO (M = Ag, Au) from Cu based metal organic frameworks for efficient catalytic reduction of p-nitrophenol

    , Article Materials Chemistry and Physics ; Volume 198 , 2017 , Pages 374-379 ; 02540584 (ISSN) Akbarzadeh, E ; Falamarzi, M ; Gholami, M. R ; Sharif University of Technology
    Abstract
    Metal Organic Frameworks (MOFs) have received enormous attention in catalysis field due to their special structures and various promising applications. One of the intriguing applications of MOFs is utilization of them as precursors for synthesis of metal oxide nanomaterials. Base on this strategy, in this work, we have applied Cu-MOF to prepare a series of noble metal nanoparticles (Ag and Au) decorated CuO (M/CuO) as efficient catalyst. As-prepared nanocomposites were characterized by various analytical techniques and their catalytic performances appraised by using of the catalytic reduction of p-nitrophenol to p-aminophenol as a reliable model reaction. Experimental results suggest that... 

    Exhaustive denitrification via chlorine oxide radical reactions for urea based on a novel photoelectrochemical cell

    , Article Water research ; Volume 170 , 2020 , Pages 115357- Shen, Z ; Zhang, Y ; Zhou, C ; Bai, J ; Chen, S ; Li, J ; Wang, J ; Guan, X ; Rahim, M ; Zhou, B ; Sharif University of Technology
    NLM (Medline)  2020
    Abstract
    Urea is a major source of nitrogen pollution in domestic sewage and its denitrification is difficult since it is very likely to be converted into ammonia or nitrate instead of expected N2. Herein, we propose an exhaustive denitrification method for urea via the oxidation of amine/ammonia-N with chlorine oxide radical, which induced from a bi-functional RuO2//WO3 anode, and the highly selective reduction of nitrate-N on cathode in photoelectrochemical cell (PEC). Under illumination, the WO3 photoanode side promotes the quantities hydroxyl and reactive chlorine radical, and these radicals are immediately combined to stronger chlorine oxide radical by RuO2 side, which obviously enhances the... 

    Green synthesis of silica nanoparticles from olive residue and investigation of their anticancer potential

    , Article Nanomedicine ; Volume 16, Issue 18 , 2021 , Pages 1581-1593 ; 17435889 (ISSN) Rezaeian, M ; Afjoul, H ; Shamloo, A ; Maleki, A ; Afjoul, N ; Sharif University of Technology
    Future Medicine Ltd  2021
    Abstract
    Graphical abstract

    Synergistic Wound Healing by Novel Ag@ZIF-8 Nanostructures

    , Article International Journal of Pharmaceutics ; Volume 629 , 2022 ; 03785173 (ISSN) Barjasteh, M ; Mohsen Dehnavi, S ; Ahmadi Seyedkhani, S ; Yahya Rahnamaee, S ; Golizadeh, M ; Sharif University of Technology
    Elsevier B.V  2022
    Abstract
    In this paper, novel zeolitic imidazolate framework-8 (ZIF-8) functionalized with Ag (Ag@ZIF-8) nanoparticles were synthesized through a green, facile and environmental-friendly process for wound dressing applications. X-ray diffraction revealed that the ZIF-8 and Ag@ZIF-8 were successfully synthesized by green solvents at ambient temperature. Field-emission scanning electron microscopy indicated a homogeneous porous blend of ∼30 nm chitosan/bacterial cellulose (CS/BC) nanofibers embedded with ∼80–110 nm nanoparticles of the ZIF-8 and Ag@ZIF-8. Transmission electron microscopy revealed the Ag@ZIF-8 nanostructures consist of ZIF-8 cores that are covered by 5–20 nm Ag nanoparticles. MTT assay... 

    Investigation on Optical and Catalytic Properties of Noble Metallic Nanoparticles in SiO2 and TiO2 Matrix

    , Ph.D. Dissertation Sharif University of Technology Sangpour, Parvaneh (Author) ; Moshfegh, Alireza (Supervisor) ; Akhavan, Omid (Supervisor)
    Abstract
    Doping metal or semiconductor nanoparticles in transparent matrix have attracted much attention for practical application in recent years. From fundamental veiw point, limiting the charge carriers and exitons in nanometric scales resulted in new quantum phenomena. In this context, transparent films containing metal nanoparticles shows an absorption peak in visible region of spectrom. Thus, by choosing an appropriate metal and controlling the size and concentration of particles in corresponding matrix, we can provide coatings with a wide rang of colors. Furthermore, thin films containing metal or metal oxide nanoparticles had been considered as nanostructure materials in research and... 

    Highly Sensitive Detection of Captopril by Fluorescein-5-Isothiocyanate-Modified Gold Nanoparticles Based on FRET& Antioxidant Activity Assay in Iranian Tea Using the Generation and Growth of Metalic Nanoparticles

    , M.Sc. Thesis Sharif University of Technology Bohloul, Arash (Author) ; Bagheri, Habib (Supervisor) ; Hormozi Nezhad, Mohammad Reza (Supervisor)
    Abstract
    The research of this work was divided into two parts. First, A novel fuorescence sensor based on fluorescence resonance energy transfer for the determination of captopril was developed. FITC molecules that are highly fluorescent in alkaline solution fluoresce weakly when they are adsorbed onto AuNP surfaces (based on affinity of AuNPs and isothiocyanate group on FITC) as a result of fluorescence resonance energy transfer. In the presence of captopril, FITC molecules are released from the AuNP surface in order to stronger affinity to AuNPs surface than FITC molecule (in order to thiol group in captopril) so the florescence intensity of FITC restore. This phenomenon was used for quantitative... 

    Silver and copper nanoparticles stabilized on ionic liquids-functionalized polyhedral oligomeric silsesquioxane (POSS): Highly active and recyclable hybrid catalysts

    , Article Polyhedron ; Volume 171 , 2019 , Pages 228-236 ; 02775387 (ISSN) Akbari, A ; Naderahmadian, A ; Eftekhari Sis, B ; Sharif University of Technology
    Elsevier Ltd  2019
    Abstract
    Two novel heterogeneous hybrid catalysts were successfully synthesized using octa-aminopropyl polyhedral oligomeric silsesquioxane hydrochloride salt (OA-POSS) and ionic liquids, followed by immobilization of Cu and Ag nanoparticles. The obtained hybrid catalysts, Cu@POSS-ILs and Ag@POSS-ILs, were characterized using FT-IR, SEM, EDX, TEM, XRD and TGA. Catalytic studies demonstrated that Cu@POSS-ILs was an excellent catalyst for click reaction in aqueous medium. Furthermore, Ag@POSS-ILs was also exhibited to be an active catalyst for 4-nitrophenol (4-NP) reduction. Simple preparation and easy catalysts recovery and recyclability of Cu@POSS-ILs and Ag@POSS-ILs for at least 3 and 6 runs,... 

    A simple shape-controlled synthesis of gold nanoparticles using nonionic surfactants

    , Article RSC Advances ; Volume 3, Issue 21 , 2013 , Pages 7726-7732 ; 20462069 (ISSN) Hormozi Nezhad, M. R ; Karami, P ; Robatjazi, H ; Sharif University of Technology
    2013
    Abstract
    Green and simple synthesis strategies have gained tremendous popularity for the production of anisotropically-shaped noble metallic nanoparticles. The long-term stability of the produced particles, the short timescale of the target reaction(s), as well as the use of non-toxic chemicals, are pivotal features of a useful green procedure. Herein we describe a simple and convenient wet-chemical approach to synthesize stable, non-toxic and water-soluble small gold nanotriangles (GNTs) and gold nanospheres (GNSs) in one step at room temperature, using Tween 20 and Tween 80, respectively. A high level of purity and monodispersity was obtained for the GNTs, in addition to an excellent colloidal... 

    Sensitive determination of dopamine in the presence of uric acid and ascorbic acid using TiO2 nanotubes modified with Pd, Pt and Au nanoparticles

    , Article Analyst ; Volume 136, Issue 11 , 2011 , Pages 2322-2329 ; 00032654 (ISSN) Mahshid, S ; Li, C ; Mahshid, S. S ; Askari, M ; Dolati, A ; Yang, L ; Luo, S ; Cai, Q ; Sharif University of Technology
    2011
    Abstract
    A simple modified TiO2 nanotubes electrode was fabricated by electrodeposition of Pd, Pt and Au nanoparticles. The TiO2 nanotubes electrode was prepared using the anodizing method, followed by modifying Pd nanoparticles onto the tubes surface, offering a uniform conductive surface for electrodeposition of Pt and Au. The performance of the modified electrode was characterized by cyclic voltammetry and differential pulse voltammetry methods. The Au/Pt/Pd/TiO2 NTs modified electrode represented a high sensitivity towards individual detection of dopamine as well as simultaneous detection of dopamine and uric acid using 0.1 M phosphate buffer solution (pH 7.00) as the base solution. In both case,... 

    Aggregates of plasmonic nanoparticles for broadband light trapping in dye-sensitized solar cells

    , Article Journal of Optics (United Kingdom) ; Volume 18, Issue 1 , November , 2015 ; 20408978 (ISSN) Sharifi, N ; Dabirian, A ; Danaei, D ; Taghavinia, N ; Sharif University of Technology
    Institute of Physics Publishing  2015
    Abstract
    Metallic nanoparticles (NPs) have not been effective in improving the overall performance of the cells with micrometer-thick absorbing layers mainly due to the parasitic optical dissipation in the metal. Here, using both experiment and theory, we demonstrate that aggregates of metallic NPs enhance the light absorption of dye-sensitized solar cells of a few micrometer-thick light absorbing layers. The composite electrode containing the optimal concentration of 5 wt% Au@SiO2 aggregates shows the enhancement of 80% and 52% in external quantum efficiency and photocurrent density, respectively. The superior performance of the aggregates relative to NP is attributed to their larger scattering... 

    Selective fluorometric determination of sulfadiazine based on the growth of silver nanoparticles on graphene quantum dots

    , Article Microchimica Acta ; Volume 187, Issue 1 , 2020 Afsharipour, R ; Haji Shabani, A. M ; Dadfarnia, S ; Kazemi, E ; Sharif University of Technology
    Springer  2020
    Abstract
    A sensitive fluorometric assay is described for the direct determination of the antibiotic sulfadiazine. Silver nanoparticles placed on graphene quantum dots (Ag NP-GQDs) were synthesized by reduction of AgNO3 with sodium borohydride in the presence of GQDs. The growth of Ag NPs on the surface of the GQDs causes quenching of the blue fluorescence of the GQDs with an emission maximum at 470 nm by surface-enhanced energy transfer. If sulfadiazine is added, it interacts with Ag NPs and fluorescence is restored. Under optimal conditions, the fluorescence increases linearly in the sulfadiazine concentration range of 0.04–22.0 μM. The detection limit is 10 nM with relative standard deviations of... 

    First principle simulation of coated hydroxychloroquine on Ag, Au and Pt nanoparticles

    , Article Scientific Reports ; Volume 11, Issue 1 , 2021 ; 20452322 (ISSN) Morad, R ; Akbari, M ; Rezaee, P ; Koochaki, A ; Maaza, M ; Jamshidi, Z ; Sharif University of Technology
    Nature Research  2021
    Abstract
    From the first month of the COVID-19 pandemic, the potential antiviral properties of hydroxychloroquine (HCQ) and chloroquine (CQ) against SARS-CoV-2 suggested that these drugs could be the appropriate therapeutic candidates. However, their side effects directed clinical tests towards optimizing safe utilization strategies. The noble metal nanoparticles (NP) are promising materials with antiviral and antibacterial properties that can deliver the drug to the target agent, thereby reducing the side effects. In this work, we applied both the quantum mechanical and classical atomistic molecular dynamics approaches to demonstrate the adsorption properties of HCQ/CQ on Ag, Au, AgAu, and Pt... 

    Doxorubicin-loaded graphene oxide nanocomposites in cancer medicine: stimuli-responsive carriers, co-delivery and suppressing resistance

    , Article Expert Opinion on Drug Delivery ; Volume 19, Issue 4 , 2022 , Pages 355-382 ; 17425247 (ISSN) Ashrafizadeh, M ; Saebfar, H ; Gholami, M.H ; Hushmandi, K ; Zabolian, A ; Bikarannejad, P ; Hashemi, M ; Daneshi, S ; Mirzaei, S ; Sharifi, E ; Kumar, A.P ; Khan, H ; Heydari Sheikh Hossein, H ; Vosough, M ; Rabiee, N ; Kumar Thakur, V ; Makvandi, P ; Mishra, Y. K ; Tay, F. R ; Wang, Y ; Zarrabi, A ; Orive, G ; Mostafavi, E ; Sharif University of Technology
    Taylor and Francis Ltd  2022
    Abstract
    Introduction: The application of doxorubicin (DOX) in cancer therapy has been limited due to its drug resistance and poor internalization. Graphene oxide (GO) nanostructures have the capacity for DOX delivery while promoting its cytotoxicity in cancer. Areas covered: The favorable characteristics of GO nanocomposites, preparation method, and application in cancer therapy are described. Then, DOX resistance in cancer, GO-mediated photothermal therapy, and DOX delivery for cancer suppression are described. Preparation of stimuli-responsive GO nanocomposites, surface functionalization, hybrid nanoparticles, and theranostic applications are emphasized in DOX chemotherapy. Expert opinion: GO... 

    Synthesis of Nanoparticles by Electrical Arc Discharge in Liquid Media and Characterization

    , Ph.D. Dissertation Sharif University of Technology Ashkarran, Ali Akbar (Author) ; Iraji Zad, Azam (Supervisor) ; Mahdavi, Mohammad (Supervisor)
    Abstract
    In this research we focus on synthesis and analysis of metal and metal oxide nanoparticles and their photocatalytic activity. At the beginning a high current DC power supply and a reactor for the electrical arc discharge process designed and implemented. Several nanoparticles such as tungsten oxide, zinc oxide, silver and gold have synthesized by this method in deionized water, deionized water including surfactants and stabilizers and analyzed. Several characterization techniques such as X-ray diffraction (XRD), dynamic light scattering (DLS) X-ray photoelectron spectroscopy (XPS), BET, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and UV-Vis spectroscopy have...