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    Synthesis of Novel Bimetallic Nanocomposite of Copper and Silver Based on Metal Organic Frameworks and Investigation of Its Application as Catalyst in Sulfonation Reaction

    , M.Sc. Thesis Sharif University of Technology Yaghoubnejad Pazoki, Parisa (Author) ; Matloubi Moghaddam, Firouz (Supervisor)
    Abstract
    In recent years, bimetallic metal-organic frameworks have attracted the great attention of researchers due to their dual properties and synergistic effects. In this research and inspired by green chemistry, the synthesis of a magnetic nanocomposite of the defective green metal-organic framework was implemented, which carries metallic silver nanoparticles (Ag NPs@Cu-MOF). Then, the sulfonated compounds were synthesized with the prepared nanocomposite because of the importance and widespread medicinal use of sulfur-containing compounds especially sulfonated compounds, and the difficulty of their preparation methods. It is noteworthy to mention that the sulfonation reaction was done by... 

    Synthesis and Characterization of TiO2 and WO3 Thin Film Photoanodes Containing Noble Metal Nanoparticles and (TiO2)x-(ZnO)1-x Nanocomposite Photanodes for H2 Production

    , Ph.D. Dissertation Sharif University of Technology Naseri Taheri, Naimeh (Author) ; Moshfegh, Ali Reza (Supervisor)
    Abstract
    Growing demand on energy and limitation and consequence of fossil fuels have caused to utilize the clean and renewable energy sources. Hydrogen is a clean energy carrier which produced just water vapor during combustion. Today, methods which are usually used to produce this fuel are based on using fossil fuel compounds. Therefore, utilizing new production methods is unavoidable. One of these methods is using semiconductors such as TiO2 to spilt water and produce H2 by solar irradiation. Reducing the energy gap of these semiconductors to match the solar spectrum, specially in its visible range, modification of their structures, surfaces and stability are the main challenges in hydrogen... 

    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... 

    Separation and Preconcentration of Gold and Silver Nanoparticles Using Cloud Point Extraction

    , M.Sc. Thesis Sharif University of Technology Zare-moghadam, Mousa (Author) ; Hormozi-Nezhad, M.R (Supervisor)
    Abstract
    Separation and identification of metal nanoparticles in surface water samples such as river water is very important. Nanoparticles specially metal nanoparticles have small dimensions can easily pass through from the body's outer immune system and disrupt biological function. Most of the nanoparticles have active surface so environmental contaminants can be absorbed on their surface and then can penerated in the body, and they may cause disease. Therefore determination of nanoparticles type and concentrations and their separation from the surrounding environment, especially surface waters is important. Separation and preconcentration of metal nanoparticles was done by using cloud point... 

    Preparation and Investigation of the Electrochemical Behavior of Sensors Based on Glassy Carbon Electrode Modified with Various Carbon Nanostructures Decorated by Some of Metal Nanoparticlesfor Determination of Ceftizoxime

    , M.Sc. Thesis Sharif University of Technology Ranjbar, Saba (Author) ; Shahrokhian, Saeed (Supervisor) ; Masoumeh Ghalkhani (Co-Advisor)
    Abstract
    In the recent years, sensors and biosensors attracts much attentions as a suitable devices in analytical chemistry. In this meantime carbon nanostructures and metal nanoparticles act as a good choice owing to their unique properties such as high electrical conductivity andmechanical and chemical stability in modification of the surface of sensors and biosensors. Because of importance of analysis the trace amounts of pharmaceutical and biological compounds, in this studies the surface of glassy carbon electrode was modified with some carbon nanostructures and metal nanoparticles for electrochemical investigation and determination of pharmaceutical and clinical compounds.In the first work, a... 

    Preparation of Metal Nanoparticles/Ionic Liquid Composites and Investigation of Their Catalytic Activity

    , M.Sc. Thesis Sharif University of Technology Gharegozloo, Nazanin (Author) ; Gholami, Mohammad Reza (Supervisor) ; Salari, Hadi (Co-Advisor)
    Abstract
    In this research Fe3O4 magnetic nanoparticles were prepared. To protect against oxidation, a shell of SiO2 was deposited on Fe3O4. Graphene oxide was prepared by the modified Hummer method and supported on the Fe3O4@SiO2 core-shell. Then, ionic liquid layer was impregnated on it. Afterward, PtAu nano alloy were synthesized on the surface of nanocomposite with the different molar ration including 100:0, 75:25, 50:50, 25:75 and 0:100. The as-prepared nanocomposite was characterized by SEM, XRD, and FT-IR analytical methods.For investigation of kinetically activity of catalysts, reduction of 4-nitrophenol with NaBH4 as reducer was used. The adsorption in different times was obtained by UV-vis... 

    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... 

    Application of Metallic Nanoparticles in Treatment of Wastewater Containing Dyestuffs

    , M.Sc. Thesis Sharif University of Technology Hosseini, Reza (Author) ; Shaygan, Jalalaldin (Supervisor)
    Abstract
    Textile industrial wastewaters are one of the most important sources of environmental contaminants. In the recent years, use of advanced oxidation processes, by producing highly active and reactive components such as hydroxyl radicals has been proposed. The aim of this research is oxidative degradation of methylene blue dye using Cu-nanoparticles immobilized on a polymer support with H2O2 as an oxidant reagent.In general, oxidative degradation of methylene blue with hydrogen proxide in the presence of immobilized CuO nanoparticles on a polymer support as the catalyst was studied. We used polyamidoamine (PAMAM) dendrimer as the polymer support for nanoparticles. fourth generation of PAMAM was... 

    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
    Elsevier 
    Abstract
    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  

    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
    Abstract
    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... 

    ZIF-8/PEDOT @ flexible carbon cloth electrode as highly efficient electrocatalyst for oxygen reduction reaction

    , Article International Journal of Hydrogen Energy ; 2019 ; 03603199 (ISSN) Asadian, E ; Shahrokhian, S ; Iraji Zad, A ; Sharif University of Technology
    Elsevier Ltd  2019
    Abstract
    Design and fabrication of highly efficient and low-cost oxygen reduction reaction (ORR) electrocatalysts is of paramount importance for practical applications. Herein, we proposed a cost-effective, metal-free catalyst based on ZIF-8 metal-organic framework nanoparticles/electro-polymerized poly(3,4-ethylenedioxythiophene) (PEDOT) film on the surface of flexible carbon cloth (CC) electrode (ZIF-8/PEDOT/CC) via a two-step procedure. For this purpose, worm-like PEDOT nanostructures were deposited on the surface of carbon fibers using a pulse electro-polymerization technique followed by facile growth of ZIF-8 polyhedra nanoparticles via a chemical bath deposition method. The ORR measurements in... 

    ZIF-8/PEDOT @ flexible carbon cloth electrode as highly efficient electrocatalyst for oxygen reduction reaction

    , Article International Journal of Hydrogen Energy ; 2019 ; 03603199 (ISSN) Asadian, E ; Shahrokhian, S ; Iraji Zad, A ; Sharif University of Technology
    Elsevier Ltd  2019
    Abstract
    Design and fabrication of highly efficient and low-cost oxygen reduction reaction (ORR) electrocatalysts is of paramount importance for practical applications. Herein, we proposed a cost-effective, metal-free catalyst based on ZIF-8 metal-organic framework nanoparticles/electro-polymerized poly(3,4-ethylenedioxythiophene) (PEDOT) film on the surface of flexible carbon cloth (CC) electrode (ZIF-8/PEDOT/CC) via a two-step procedure. For this purpose, worm-like PEDOT nanostructures were deposited on the surface of carbon fibers using a pulse electro-polymerization technique followed by facile growth of ZIF-8 polyhedra nanoparticles via a chemical bath deposition method. The ORR measurements in... 

    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) Kheirabadi, M ; Samadi, M ; Asadian, E ; Zhou, Y ; Dong, C ; Zhang, J ; Moshfegh Zaker, A. R ; Sharif University of Technology
    Academic Press Inc  2019
    Abstract
    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... 

    Voltammetric studies of Azathioprine on the surface of graphite electrode modified with graphene nanosheets decorated with Ag nanoparticles

    , Article Materials Science and Engineering C ; Volume 58 , 2016 , Pages 1098-1104 ; 09284931 (ISSN) Asadian, E ; Iraji Zad, A ; Shahrokhian, S ; Sharif University of Technology
    Elsevier Ltd 
    Abstract
    By using graphene nanosheets decorated with Ag nanoparticles (AgNPs-G) as an effective approach for the surface modification of pyrolytic graphite electrode (PGE), a sensing platform was fabricated for the sensitive voltammetric determination of Azathioprine (Aza). The prepared AgNPs-G nanosheets were characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), UV-vis and Raman spectroscopy techniques. The electrochemical behavior of Aza was investigated by means of cyclic voltammetry. Comparing to the bare PGE, a remarkable enhancement was observed in the response characteristics of Aza on the surface of the modified electrode (AgNPs-G/PGE) as well as a noticeable... 

    Utilizing the moiré deflectometry-based detection method improves the detection sensitivity for gold nanoparticles trapped by optical tweezers

    , Article Journal of the Optical Society of America B: Optical Physics ; Volume 38, Issue 7 , 2021 , Pages 2135-2140 ; 07403224 (ISSN) Reihani, S. N ; Khorshad, A. A ; Sharif University of Technology
    The Optical Society  2021
    Abstract
    Gold nanoparticles (GNPs) are very often used as handles for nanotechnological micromanipulation. In this regard, optical trapping of GNPs is of great importance, in which locating the trapped GNP within the focal spot with nanometer precision is crucial. Very recently, we have introduced a new position detection system for optical tweezers based on moiré deflectometry (MD). Here we show, both theoretically and experimentally, that an MD detection system could provide significantly larger detection sensitivity for a trapped GNP compared to that provided by conventional back focal plane (BFP) detection systems. For instance, for a trapped 200 nm GNP, the detection sensitivity provided by the... 

    Utilizing graphene oxide/gold/methylene blue ternary nanocomposite as a visible light photocatalyst for a plasmon-enhanced singlet oxygen generation

    , Article Reaction Kinetics, Mechanisms and Catalysis ; Volume 135, Issue 5 , 2022 , Pages 2851-2865 ; 18785190 (ISSN) Tamtaji, M ; Kazemeini, M ; Sharif University of Technology
    Springer Science and Business Media B.V  2022
    Abstract
    In this study, graphene oxide/gold/methylene blue (GO/Au/MB) ternary composites were synthesized and characterized through UV–vis, FTIR, XRD, XPS, SEM, and TEM analyses towards plasmon-enhanced singlet oxygen (1O2) generation. Through using gold nanoparticles and MB photosensitizers, the visible light adsorption capability of GO was enhanced by 115%. Moreover, applying this ternary composite as a photocatalyst under visible light interestingly revealed a drastic step-increase of 14% (i.e., from 9 to 23%) in the conversion of photooxygenation of Anthracene. This behavior was rationalized using finite-difference time-domain (FDTD) simulations which confirms the plasmonic field of gold... 

    Useful multivariate kinetic analysis: Size determination based on cystein-induced aggregation of gold nanoparticles

    , Article Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy ; Volume 115 , 2013 , Pages 588-594 ; 13861425 (ISSN) Rabbani, F ; Nezhad, M. R. H ; Abdollahi, H ; Sharif University of Technology
    2013
    Abstract
    This study describes spectrometric monitored kinetic processes to determine the size of citrate-capped Au nanoparticles (Au NPs) based on aggregation induced by L-cysteine (L-Cys) as a molecular linker. The Au NPs association process is thoroughly dependent on pH, concentration and size of nanoparticles. Size dependency of aggregation inspirits to determine the average diameters of Au NPs. For this aim the procedure is achieved in aqueous medium at pH 7 (phosphate buffer), and multivariate data including kinetic spectra of Au NPs are collected during aggregation process. Subsequently partial least squares (PLS) modeling is carried out analyzing the obtained data. The model is built on the... 

    Ultrafast and simultaneous removal of anionic and cationic dyes by nanodiamond/UiO-66 hybrid nanocomposite

    , Article Chemosphere ; Volume 247 , May , 2020 Molavi, H ; Neshastehgar, M ; Shojaei, A ; Ghashghaeinejad, H ; Sharif University of Technology
    Elsevier Ltd  2020
    Abstract
    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... 

    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...