Sharif Digital Repository

During fuel combustion, aromatic sulfur compounds in energy fuels convert into sulfur oxides, which cause major environmental problems such as acidic rain, global warming, and air pollution. Absorption desulfurization is one of the promising and economical methods to remove these sulfur compounds from fuels. Metal-organic frameworks (MOFs) are a class of nanoporous materials that are of interest for use as adsorbents due to their high specific surface area, unique surface adsorption properties, high adsorption capacity, tunable porosity, flexible dynamic behavior, and diversity in functional and metal groups. In this research, we first synthesized five metal-organic frameworks, namely... 

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... 

The main focus of this thesis was on fluorescence sensors development based on carbon dots and deep eutectic solvents. Accordingly, an attempt was made to synthesize carbon dots and modified with deep eutectic solvents as biocompatible sensors. Eventually, development and application of these sensors in analytical systems ultimately led to satisfactory and comparable results with previous methods. In the first project, a rapid and miniaturized fluorescent probe based on the ultrasound‒assisted formation of carbon dots (CDs) in a metallic deep eutectic solvent (MDES) was developed and conveniently implemented to detect 4-MeI in commercial dark soft drinks. In-situ synthesis of CDs-chelated... 

Among various methods for purifying water from dyes, adsorption takes advantage of simplicity, high efficiency, no secondary-pollution, and inexpensiveness. In this project Halloysite nanoparticles were applied to prepare a series of modified polyAcrylamide- quince seed gum hydrogels (QS/PAAm/Haln). The obtained hydrogels demonstrated improved efficiency as adsorbent in removing methylene blue (MB) from aqueous media. The structure of the prepared hydrogel nanocomposites were identified by X-ray diffraction, Brunauer-Emmett-Teller surface area analysis, Fourier-transform infrared spectroscopy, scanning electron microscope and energy-dispersive X-ray spectroscopy. Kinetics, thermodynamic,... 

Due to the technology advancement and the large-scale application of lithium-ion batteries in recent years, the market demand for lithium is growing rapidly and the availability of land lithium resources is decreasing significantly. As such, the focus of lithium extraction technologies has shifted to water lithium resources. Among various aqueous recovery technologies, the lithium ion-sieve (LIS) technology is considered the most promising one. This is because LISs are excellent adsorbents with high lithium uptake capacity, superior lithium selectivity, and good cycle performance. TiO2-based nanotubes are an appropriate option for adsorbing lithium from solution due to their high specific... 

This research aims to extract lithium from brines with low concentrations. Aluminum hydroxide has been chosen as a suitable and selective adsorbent. This absorbent is made by combining one of the aluminum salts in an alkaline environment. Due to the high cost of providing the raw materials for making the absorbent and sensitivity to the pH value and environmental harm, it is suggested that the absorbent be made by hydrolysis of water by aluminum particles. The manufacturing method has shown promising results in such a way that with the combination of NaCl+CaO and aluminum and activation by ball mill, the amount of extraction is 97% at a temperature of 40 ˚C; in two days, the molar ratio of...