Sharif Digital Repository

In recent years, quantum dots specially NIR QDs like lead sulfide have attracted a lot of attentions in various bioapplications such as bioimaging, stem cell tracking, etc. However, these materials are generally synthesized by using organic lagands like oleic acid which is not appropriate for bioapplications. Moreover, the cytotoxicity of these materials have severely restricted their applications. In this research, lead sulfide quantum dots were synthesized via a hot injection route. The nanocrystals had an average size of 3 nm passivated with oleic acid ligands and graphene nanosheets. Excitonic and photoluminescence peaks were observed in wavelengths of 950 and 1100 nm, respectively.... 

Removal of petroleum hydrocarbons from water is one of the environmental challenges. In this study the functionalized magnetic nanoparticles (MNPs) was used to remove kerosene oil as contaminants from water. Effective factors on adsorption of oil on MNPs were investigated. Magnetic nanoparticles were synthesized on activated carbon derived from almond shell and after a coating by silica, it Was functionalized by NH2 and COOH functional groups. After preparation of kerosene oil/water stable emulsions by emulsifier, the adsorption capacity of AC@Fe3O4@SiO2-NH2-COOH was evaluated. The adsorbent was characterized by various physicochemical techniques such as transmission electron microscopy,... 

In this study, ZIF-8 was synthesized at room temperature and Then ZIF-8/PEGDA mixed matrix membranes with 5 and 10% of ZIF-8 were prepared by UV photopolymerization to analyze the separation CO2 from natural gas for the first time. The permeation results of gases in mixed matrix membranes in the temperature range of 35-75 degrees centigrade and in pressure ranging from 4-15 bar show the permeability of gases in mixed matrix membranes with 5 and 10% increase more than a pure polymer nearly 14.3 and 31%, respectively, But, CO2=CH4 selectivity decreases. The gas sorption in ZIF-8 was measured in the temperature range up to 75 ◦C and pressure ranging from 2-5 bar. The adsorption isotherm follows... 

In this research work, to enhance the performance of the conventional spinning disk reactors, a novel type of spinning disk reactor has been proposed and tested successfully through the synthesis of barium sulfate nanoparticles by means of the reactive precipitation. This reactor consists of two coaxial rotating disks placed horizontally in a cylindrical chamber. The experimental results clearly indicate the capability of the proposed reactor in the synthesis of nanoparticles with the smaller mean particle size and the narrower particle size distribution compared to those obtained in various process intensification devices such that barium sulfate nanoparticles with a mean particle size of... 

Food spoilage cased by food-borne pathogens and microorganisms is a serious problem in the food and packaging industry. Then, the demand for antibacterial agents in food packaging is growing. The antibacterial efficacy of some nanocomposites has been recognized and exploited in various industries, including the packaging industry. Also, metal organic frameworks due to their porous structure, are used in various fields such as food packaging. The purpose of this work, is synthesize hybrid nanocomposite that have promising antibacterial activity for preparation of food packaging films. Carboxymethyl cellulose is a derivative of cellulose fiber. The use of carboxymethyl cellulose as... 

Solar energy is one of the man's solutions to cope with problems involved in exhaustible fossil resources. In this regard, using photocatalysts is a practical and rational pproach.Nanotechnology facilitates using catalysts and photocatalysts with more productivity.TiO2 semiconductor is one of the most popular material in this field but its efficiency is low by several factors such as being inactive in visible light, recombination and the high cost of using noble metals. In this research, we tried to fix these limitations by creating a p-n junction TiO2 - NiO nanocomposite. The samples are made by three methods: impregnation, ultrasonic assisted modified impregnation with ammonium hydroxide... 

The main objective of the present work was to improve the turbulence in single drops using ferrofluids (magnetic nanoparticles) in the presence of uniform and oscillating magnetic fields. In this regard, magnetite nanoparticles ($\mathrm{Fe_3O_4}$) were synthesized by co-precipitation method, characterized using DLS, FT-IR, XRD, VSM, and TEM, and their stability was checked by UV-Vis. The obtained results indicate the proper synthesis of nanoparticles with a mean diameter of about 20 nm and by coating their surfaces by silane that were well stabilized in the base fluid. In the numerical section, the governing equations of transport phenomena for a single drop containing magnetic fluids were...