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    Electrodeposition of Rhenium and Nickel Nanoparticles

    , M.Sc. Thesis Sharif University of Technology Ataee, Hamed (Author) ; Sadrnezhad, Khatiboleslam (Supervisor)
    Abstract
    In the last decade, a great deal of attention has been paid to the study of synthesis of Nanoparticles, because of the widespread use of this material in applications involving Fuel cells and magnetic devices. In this thesis, we report some interesting features in the electrodeposition of metallic nanoparticles. The electrochemical phase formation of rhenium and nickel on the surface of P-Si (100) substrate plus morphological, topographical and fractal aspects of the accumulated surface were investigated in this research by means of chronoamperometry method and by utilization of AFM and SEM. The nucleation and growth mechanisms on silicon electrode are characterized using cyclic voltammetry... 

    Synthesis and Characterization of TiO2 Based on Carbon (Activated Carbon and Carbon Nanotube) and Investigation of its Catalytic Activity on Environmental Pollutions

    , M.Sc. Thesis Sharif University of Technology Zarezade, Mitra (Author) ; Gholami, Mohammad Reza (Supervisor)
    Abstract
    Pure NanoParticles of TiO2 and Nanocomposite catalysts of TiO2 , activated carbon (TiO2/AC) and multi-walled carbon nanotube (TiO2/MWCNT) were prepared by a sol –Gel method using TetraisoPropylorthotitanat (Tipt) as a precursor. The catalysts were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), diffuse reflectance uv-vis spectroscopy (DRS) and N2 adsorption – desorption measurements. The photoactivity of samples was evaluated by Acid Blue 92 (AB 92) degradation. The analysis results show that compared with pure Nanoparticles of TiO2, the spherical – shaped TiO2 particles are well – dispersed in TiO2/AC. In TiO2/MWCNT, the coating has special mechanism that... 

    Investigation of Nucleation and Growth of Metallic Nanoparticlaes from the Gas Phase by Molecular Dynamic Simulation

    , M.Sc. Thesis Sharif University of Technology Naghibi Nezhad, Mohsen (Author) ; Askari, Masoud (Supervisor) ; Simchi, Abdolreza (Supervisor)
    Abstract
    Formation of nanoparticles by the gas phase condensation process is one of the most promising methods for the nanoparticles synthesis. Finding the correlations between adjustable parameters of the process and nanoparticles properties depends on how parameters affect the mechanism of nucleation and growth. The use of classical nucleation theory at nanoscale leads to unacceptable results; hence, approaches such as molecular dynamic simulation (MD) have been proposed to investigate the mechanism of nucleation and growth at atomic scale. In the present work, the formation of iron clusters from a supersaturated gas phase was investigated via molecular dynamics simulation. For thermalization of... 

    Simulating Flow over Nanoparticles through Microchannels Using Lattice Boltzmann Method

    , M.Sc. Thesis Sharif University of Technology Setayeshgar, Alireza (Author) ; Darbandi, Masoud (Supervisor)
    Abstract
    Novel manufacturing technologies in micro scales, such as micro machining, guide us through constructing micro scale systems known as MEMS. These systems have a wide range of applications, from fabrication of electrostatic, magnetic, pneumatic sensors and actuators to micro mechanical gears and motors. Also, MEMS applications involve the manipulation of one or more fluids, known as microfluids. Simulation of flow through microchannels over nano particles has important applications in solid particles transport. In this flow, the rarefaction phenomenon will affect the flow behavior and its subsequent impacts such as aerodynamic drag forces. In this work, we use the Lattice Boltzmann method... 

    Hydrothermal Synthesis of Copper (II) Oxide Nanparticles at Supercritical Conditions and Their Application in Decantamination of Tritium Polluted Streams

    , M.Sc. Thesis Sharif University of Technology Hosseinpour, Morteza (Author) ; Ghofrani, Mohammad Bagher (Supervisor) ; Ahmadi, Javad (Supervisor) ; Outokesh, Mohammad (Co-Advisor) ; Mosavand, Tahereh (Co-Advisor)

    Synthesis of Nanoparticles and Application of the Prepared Catalyst for Some Organic Reactions, Efficient Synthesis of New Thiophene Derivatives and Asymmetric Synthesis of Sulfonic Acid Derivatives

    , Ph.D. Dissertation Sharif University of Technology Saeidian, Hamdollah (Author) ; Matloubi Moghaddam, Firouz (Supervisor)
    Abstract
    ZnO nanopowder has been successfully synthesized by a microwave-assisted solution approach using Zn(CH3CO2)2.2H2O and NaOH. The results obtained from XRD, SEM and TEM show that the mean particle size is 30 nm. SEM and TEM micrographs of ZnO nanopowder also reveal that nanoparticles have spherical shape. A convenient one-pot multi-component reaction of aromatic aldehydes, enolizable ketones or β-keto esters and acetonitrile in the presence of acetyl chloride and 10 mol % ZnO nanoparticles for the synthesis of β-acetamido ketones/esters at room temperature is described. Catalytic activity of ZnO nanopowder for o-acylation of alcohol and phenol has also been investigated. On the other hand,... 

    Molecular Dynamics Simulation of Nanoscale Effects in Nanomanipulation

    , Ph.D. Dissertation Sharif University of Technology Mahboobi, Hanif (Author) ; Meghdari, Ali (Supervisor)
    Abstract
    Metallic clusters are among the best candidates that may be utilized as building blocks for constructing nanostructures. Despite their great potential, a variety of questions arises about their suitability as building blocks at the nanoscale level. One of the key factors in the assembly of nanoclusters is the precise positioning that is required by a manipulation system. The response of clusters, which are subjected to this process, is of great importance. Currently, the size of clusters used as building blocks is shrinking down to a few nanometers. In such cases, the particle nature of matter plays an important role in manipulator/cluster/substrate interactions. Having a deeper insight into... 

    The Effect of Solvent Type on the Characteristic of TiO2 Nanometric Coatings Produced by Electrophoretic Method

    , M.Sc. Thesis Sharif University of Technology Farrokhi Rad, Morteza (Author) ; Ghorbani, Mohammad (Supervisor)
    Abstract
    Titania is semiconductor material and have many applications including photocatalysis, photochromic, air and water purification, sensors, and solar cell. In electrophoretic deposition, charged particles dispersed in a stable suspension move towards an oppositely charged electrode, and form dense layer of deposit on it. In this investigation electrophoretic deposition of titania nano-particles in suspensions prepared by different solvents (methanol, ethanol and butanol) with and without dispersant (triethanolamine and polyethylenimine), was studied. Well stabilized suspensions, prepared for electrophoretic deposition. The effects of solvent type, additive concentration, mechanism of particles... 

    Controlled Microwave-assisted Synthesis of ZnFe2O4 Nanoparticles and Investigation of their Catalytic Activity in Organic Reactions

    , M.Sc. Thesis Sharif University of Technology Doulabi, Malihe (Author) ; Matloubi Moghaddam, Firouz (Supervisor)
    Abstract
    ZnFe2O4 nanoparticles have been successfully prepared through a controlled microwave–assisted co-precipitation as well as conventional co-precipitation. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM) were used for the structural, morphological and magnetic investigation of the product. Average particle size was obtained as 12 nm from XRD. Catalytic activity of ZnFe2O4 nanopowder for O-acylation of alcohol and phenol has been investigated. A trace amount of ZnFe2O4 has been effectively used as a nanocatalyst for the acylation of alcohol and phenol in acetic anhydride.

     

    Fabrication of Ni -P -MoS2 Composite Coating by Electroless Deposition and Evaluation of Its Tribological Properties

    , M.Sc. Thesis Sharif University of Technology Majidian, Maryam (Author) ; Ghorbani, Mohammad (Supervisor) ; Afshar, Abdollah (Supervisor)
    Abstract
    Adding solid lubricant particles such as PTFE, Graphite and MoS2, has major influence on electroless composite nickel coatings in order to make low friction surfaces. Among these lubricants, MoS2 has attracted great attention due to its highest stability under wearing condition. In this work Ni-P-MoS2 composite coatings using MoS2 nano-particles have been made and in the next step, we evaluated tribological properties of these coatings. For exploring these coatings different experiments were utilized, like Scanning Electron Microscope study (SEM), chemical composition analysis exploiting AAS and XRF method, and thickness measurements. Two kinds of surfactants, CTAB and PVP, have been applied... 

    Thermodynamic and Kinetic Study for Production of Micro and Nano Poly(Ethylene Terephthalate) Particles With Supercritical System

    , M.Sc. Thesis Sharif University of Technology Oghazian, Farhad (Author) ; Goodarznia, Iraj (Supervisor)
    Abstract
    It is well known that poly(ethylene terephthalate) (PET) is a high melting compound which has exceptional value as a fiber and film-making material, and which currently dominates the whole field of linear polyester substances. However, the high viscosity and limited solubility in liquid solvents restrict its processing to powders and hence the range of applications of such a polymer. Traditionally, crushing, mechanical grinding, ball milling and precipitation from solution are methods for producing powders. The first three ones inevitably change the property of materials. The last one is carried out on the basis of the application of an anti-solvent to decrease the solubility of a... 

    CdS:Mn and CdS:O Nanoparticles Growth via Thermochemical and Microwave Methods and Studding the Photoluminescence Properties

    , M.Sc. Thesis Sharif University of Technology Amrollahi Biuki, Rezvaneh (Author) ; Taghavinia, Nima (Supervisor)
    Abstract
    The optimization of CdS photoluminescence nanoparticles which has been considered as one of the most important II-VI semiconductors has been studied here. As the first step, synthesis parameters effect on CdS:Mn photoluminescence intensity has been regarded by thermochemical method. Effect of parameters like pH solution, heating time and capping agent concentration on photoluminescence of these materials has been experimented. What seemed so important was reaching nanoparticles with suitable nano size and nano structure and having highly photoluminescence intensity. Observing the good effect of Oxygen on photoluminescence of CdS nanoparticles leaded us to concentrate on synthesizing CdS:O... 

    Experimental Study of NanoFluid Heat Transfer in the Entrance Region

    , M.Sc. Thesis Sharif University of Technology Ezzati, Davoud (Author) ; Nouri Brojerdi, Ali (Supervisor)
    Abstract
    This project reports an experimental work on the convection heat transfer of nanofluids, made of -AL2O3 nanoparticles and de-ionized water, flowing through a copper tube in the laminar flow regime. The results showed considerable enhancement of convective heat transfer using the nanofluids. The enhancement was particularly significant in the entrance region, and was much higher than that solely due to the enhancement on thermal conduction. It was also shown that the classical Seider and Tate equation failed to predict the heat transfer behavior of nanofluids. Possible reasons for the enhancement were discussed. Migration of nanoparticles and the resulting disturbance of the boundary layer... 

    Gas Separation by TEG and Zeolite Na-Y Nano Particles Liquid Membrane

    , M.Sc. Thesis Sharif University of Technology Asadollahi, Mahdieh (Author) ; Bastani, Dariuosh (Supervisor) ; Kazemian, Hossein (Supervisor)
    Abstract
    In this research, in order to investigate the effect of zeolites nanoparticles on the separation performance of a liquid membrane, a TEG/Nano Na-Y was developed. To do this, a high yield nano zeolite Na-Y was synthesized using mid-synthesis addition method . The synthesized samples were characterized by XRD, FT-IR, and SEM (EDX) instrumental techniques. A supported liquid membrane was prepared by impregnating a porous hydrophilic PVDF support with TEG and nano zeolite Na-Y. Permeances of single gas components of CO2, N2 and O2 were carried out at different pressures of 0.8, 1.8 and 3.7 bar. The single gases permeances were found to be: CO2 > N2 > O2. The results were shown that higher weight... 

    Improving Hydrogen Sensing by Adding Additives in Nanostructure WO3 Films

    , M.Sc. Thesis Sharif University of Technology Fardindoost, Somayyeh (Author) ; Iraji Zad, Azam (Supervisor) ; Mahdavi, Mohammad (Supervisor)
    Abstract
    The present work emphasizes on hydrogen resistance- sensing properties of WO3 films prepared by Sol-gel routs. The sol-gel is a simple and low cost rout which makes film with high homogeneity and low processing temperature .To improve Hydrogen sensing we modified WO3 films with Pd catalysts by Sol-gel and Electroless methods. AFM , EDX, SEM , XPS , XRD , were applied to analyze structure, morphology and Chemical composition of the fabricated thin films. We measured resistance sensing behavior of prepared films in exposure to different concentration of Hydrogen. All the films were tested under the same conditions. We measured resistance sensing in exposure to concentration below 10000 ppm... 

    Synthesis of MoS2 Nanoparticles and Their Application as Nanocatalyst for Hydrodesulfurization Process

    , M.Sc. Thesis Sharif University of Technology Parviz, Dorsa (Author) ; Kazemeini, Mohammad (Supervisor) ; Rashidi, Alimorad (Supervisor)
    Abstract
    Highly active unsupported MoO3 and (Co) MoO3 catalysts were synthesized utilizing the solution combustion method where the Ammonium molybdate powder and an organic additive were used as precursors. Different organic materials including Ethylene Diamin Tetra-acetic acid (EDTA), Polyethylene Glycol 200 (PEG 200), Sorbitol and Urea were used as additive in order to investigate the effect of additive structure on morphology and particle size of products. Also various reaction parameters such as the additive/Mo molar ratio, concentration of metal ion in solution, pH of the reaction and temperature of the synthesis media were changed to study effects on product morphology and size. Outcomes were... 

    Extraction of Anthocyanins and Total Phenolics from Dried Red Grape Skin by Super Heated Solvent and Production of NanoPparticle by Super Critical Fluid

    , M.Sc. Thesis Sharif University of Technology Shahmahmoodi, Mohammad (Author) ; Goodarznia, Iraj (Supervisor)
    Abstract
    Red grape skin has a lot of antioxidant that called Anthocyanins. In this research this material has been studied and amount of extraction of them have been studied by changing the operational parameter and particle size in taguchi procedure. Pressurized liquid extraction (PLE) was used to extract Anthocyanins from Dried Red Grape Skin (DRGS) with acidified Ethanol solvent (1 %( v/v) of HCl) in 90-120°C, 10-40 bar, and 30 min extraction time. In this study, effect of particle size distribution of DRGS was considered and the results showed that with increasing the temperature (from 90 to 120 °C in 10 °C increments) and decreasing the pressure and particle size the extraction of Anthocyanins... 

    Preparation of TEG Supported Liquid Membrane with Nano Particles of LTA Type Zeolite and Investigation of The Membrane Performance in Gas Separation

    , M.Sc. Thesis Sharif University of Technology Esmaeili, Nazila (Author) ; Bastani, Daryush (Supervisor) ; Kazemian, Hossein (Supervisor)
    Abstract
    The purpose of this research project was to improve the performance of TEG liquid membrane in separation of gas mixtures by adding zeolite LTA nanoparticles. Therefore, the NaA zeolite particles with nano size were synthesized with hydrothermal method at optimized condition. The supported liquid membrane with hydrophilic PVDF membrane and triethylene Glycol (TEG) was prepared in two different conditions. In the first one, the pores of the supporting membrane were filled with triethylene Glycol, whereas in the second one the pores were filled with the mixture of triethylene Glycol along with the 5 wt% and 10 wt% zeolite nanoparticles. The performances of prepared membranes were investigated... 

    Electrophoretic Deposition of TiO2 Nanoparticles and Fiber for DSC Application

    , M.Sc. Thesis Sharif University of Technology Shooshtari, Leyla (Author) ; Taghavinia, Nima (Supervisor)
    Abstract
    Dye Sensitized Solar cell (DSC) is the third class of solar cell, which consists of a nanocrystalline, mesoporous of semiconductor(The best one is Tio2), covered with a monolayer of dye molecules, platinum coated on FTO as a counter electrode and a redox electrolyte. This Photovoltaic cell which is promising low-cost materials, works on electron separation of dye molecule, and electron injection to semiconductor’s conduction photo- electrode structure and its porosity is affected the DSC’s performance. Recently, use of electrophoretic deposition (EPD) for TiO2 electrode (which best found for photo-electrode in DSC) fabrication has gained increased interests. In this method charged particles... 

    Application of Zero Valent Iron Nanoparticles for Removal of Poly Chlorinated Biphenyls (PCBs) Contaminants

    , M.Sc. Thesis Sharif University of Technology Karkooti, Amin (Author) ; Vossoughi, Manoochehr (Supervisor) ; Borgheei, Mahdi (Supervisor)
    Abstract
    Recent advances suggest that many of the issues involving in improving water quality could be solved by using nano particles. Aquifer and groundwater remediation are also critical issues. Becoming more important as water supplies steadily decrease and demand continues to increase. Although some of the remediation technologies available today are , they are costly and time-consuming, especially pump and treat methods. A wide range of nano particles have been used for the removal of organic and inorganic contaminants. In the first part of this work, zero-valent Iron nano particles was synthesized and was covered with nickel as catalyst. Diameter of the synthesized nano particles was...