Sharif Digital Repository

Nanoporous metal-organic frameworks are among the new and advanced compounds that have attracted attention of researchers due to their unique properties such as high surface area, high porosity and regular structure. These compounds can catalyze and degrade pollutants. Due to the high consumption of organic compounds, especially textile dyes, the pollution caused by wastewater is increasing in various industries. Disposal of wastewater containing organic pollutants into aquatic environments can alter the natural color, change the taste of water and disturb the life of living organisms. If the dyes are left untreated in aquatic ecosystems, they can remain in the environment for a very long... 

It is necessary to monitor pollutants in aquatic samples, because many of these compounds can pose threats to human health and the ecosystem. Separation technology based on magnetic materials has received considerable attention in recent years. The magnetic extraction method is not only convenient, economical and highly efficient, but it also overcomes problems with conventional solid-phase extraction. In order to remove anionic dyes from single and ternary systems, zinc ferrite nanoparticle was synthesized using co-precipitation method and its surface was modified by Cetyltrimethyl ammonium bromide (CTAB) cationic surfactant. Surface characteristics of ZFN-CTAB was studied using Fourier... 

Photocatalytic as well as photo-Fenton-like processes are promising and ideal technologies for using solar energy to regenerate energy as well as regenerate and revitalize the environment. In fact, photocatalytic processes are one of the most important chemical methods to reduce energy and environmental crises by converting endless solar energy into pure chemical potential. Photocatalytic processes and photocatalysts based on metal-organic frameworks (MOFs) have attracted special attention in recent years due to their excellent and unique properties such as adjustable structure and optical properties. In fact, metal-organic frameworks, as a group of newly emerged crystalline porous... 

In this research, an adsorptive affinity membrane has been prepared based on the combination of the nanofiber structure’s intrinsic characteristic in the dye adsorption and its membrane filtration properties. Electrospinning method has been used to prepare chitosan/poly(vinyl alcohol) (PVA) nanofibers. The morphology and properties of the prepared nanofibrous membranes were characterized using Fourier-transform infrared spectroscopy (FT-IR), field-emission scanning electron microscopy (FE-SEM), image processing, atomic force microscopy (AFM), and thermogravimetric analysis (TGA). Also, the major drawback of electrospun nanofibrous membranes (ENMs) is their low mechanical resistance. So,... 

Azo dyes that are the most common dyes in textile industries, are toxic and stable complex compounds. Release of this dyes in environment disturb the ecosystem and endanger human health. So selection of an appropriate method for treatment of them is a sensitive work. photocatalytic degradation is one of the best promising methods because of its perfect mineralization, middle condition and lack of creating the secondary pollutant. In this research CuO/CNT nanocomposite was synthesized and used as a photocatalyst. The surface features of CuO/CNT were surveyed by using Fourier transform infrared(FTIR), X-ray diffraction (XRD) and Scanning electron microscopy (SEM). Photocatalytic efficiency of... 

During the recent years, shortage of drinking water is one of the concerns of the society and necessity of purification of contaminated water are taken into consideration. Different methods to be developed to prevent problematic pollutions. Among these different methods the most common one is adsorption. In this thesis, the copper oxide nanoparticle was synthesized and its surface was modified using N-(2-aminoethyl)-3-(trimethoxysilyl)propylamine. The bi-amino surface functionalized nanoparticle was used to remove anionic dyes from single and binary systems. The scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), Energy-dispersive X-ray spectroscopy (EDAX)... 

Environmental issues and lack of drinking water had forced researchers to find some alternatives in order to wastewater treatment. Since dyes are used in a variety of industrial application such as textile, pharmaceutical, etc.; therefore, wastewater of these factories makes several environmental problems. Using catalysis under UV- irradiation (photocatalysis) is one of the cases that is used in wastewater treatment which the catalyst stimulated under UV- irradiation and this process degraded dyes. In this work, reactive red 198 degradation is investigated with MIL-53(Fe) and MIL-100(Fe) and in the literature section, the methods that was implemented by other researchers is studied.... 

Increased photo catalytic activity of NiO and 〖Co〗_3 O_4 were obtained by Ni〖Co〗_2 O_4 synthesizing and supporting functionalized multiwall carbon nano-tubes via calcinations followed by hydrothermal precipitation. NiO, 〖Co〗_3 O_4 and Ni〖Co〗_2 O_4 were prepared in the same procedure exactly for the subsequent photo catalytic activity to be compared to Ni〖Co〗_2 O_4/MWCNT later on. The photo catalytic degradation of Reactive Red 120 dye as a deazo organic pollutant model was used for experimental photo catalytic performance analysis. The CCD method was applied for experimental designing, modeling, and optimizing the operational parameters of the photo catalytic degradation of RR120 using... 

Physical processes such as adsorption and membrane filtration are in progress and considered as efficient methods in separation and treatment of organic pollutants from petrochemical and colored wastewaters. The advantages of these methods include high energy efficiency, low cost, facile process, and regeneration and implementation ability for a wide range of contaminants. Nevertheless,requirement of suitable materials as adsorbents with high adsorption capacity, capability of preparing membranes based on these materials, optimization of process conditions and removal improvement have still remained as the main challenges; therefore, these topics have been mentioned as main aims of this... 

In present work, we fabricated novel heterojunction magnetic composite and the goo visible-light-harvesting photocatalysts through integration of ZnFe2O4 and MIL-53 by facile solvothermal method. To understand physical and chemical structure prepared material and morphology of samples, The XRD,FTIR, FESEM, DRS and VSM analysis were carried out. The ZFO/M53Fe/vis-light system reveled 92.3% dye degradation which enhanced photo catalyst reactivity for the decolorization of Direct red 23 as anionic dye under irraditation of LED lamp through AOP environment friendly technology, which are significantly higher than those of pure ZFO and M53Fe semiconductors. more ever ,aforementioned composite... 

Immediate control of pandemic influenza to avoid casualties and financial losses is an important issue. In this thesis, two types of controllers including optimal controller and adaptive generalized predictive controller based on linear input-output model, with vaccine, treatment and quarantine being controlling variables, have been used to control influenza. Each controlling methods were investigated for different states including single-input single-output and multi-input single-output. Single-input single-output and multi-input single-output models are identified as online and offline using least squares method. Since it is difficult to exactly identify the model parameters, especially at... 

The tension leg platform is one of the compliant structures which are generally utilized for deep water oil explorations. With respect to the horizontal degrees of freedom, it behaves like a floating structure moored by vertical tethers which are pretension due to the excess buoyancy of the platform, whereas with respect to vertical degrees of freedom it is stiff and resembles a fixed structure and is not allowed to float freely. A sudden disconnection of a tendon causes a change of stiffness and unbalance of forces and moments of the total system. The objective of this study is experimental and numerical investigation on behavior of ISSC TLP. Experiments were performed in the National... 

Briefly in this thesis, these subjects have been investigated: In recent years, water is used as a solvent instead of an organic solvents have become more and more important due to cheap and environmental consideration. In this context, preparation of quinoxaline, pyrrole, new 1,4-dihydropyridine and reduction of imine to amine with 1,4-dihydropyridine derivatives as the reducing agents with the use of one-pot multicomponent reaction have been reported. The existence of several hydrogen bonding groups (NH) in the new dihydropyridines they acts as biologically active compounds in the forthcoming years. In continuation, oxidation of thiols to disulfides in the presence of NBS and NCS and... 

In this thesis, heterogenous catalysts based on magnetic nanoparticles were synthesized. In these catalysts, magnetic nanoparticles were coated with defferent fuctional groups to produce a catalyst with magnetic properties which is easily separated from the reaction medium. The structure of synthesized catalyst was characterized using techniques such as transmission electron microscopy (TEM), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), and CHNS elemental analysis. Easy preparation, low cost, biodegradability and high thermal stability are advantages of these catalysts. At the end, the catalytic properties of resulted catalysts were investigated in many... 

Octahedral crystals of Fe-Metal-organic frameworks like Fe-MIL-101, which is the most stable and active metal-organic frameworks; in combination with graphitic carbon nitride nanosheets could significantly enhance the photocatalytic activity of g-C3N4 for inorganic dye degradation under the irradiation of visible light application. This appropriate cocatalyst modifies the performance of semiconductor via suppressing the recombination of photo-induced carriers and since the synthesized composite prepared by in-situ procedure possesses close contact between each other, the migration of electrons in the photocatalytic reaction will be continued, so the degradation process via the active species... 

The current thesis deals with designing of functionalized nanoporous catalysts modified with organic groups and ionic liquids and their applications for some challenging organic reactions such as synthesis of adipic acid and fatty acid esterifications. In this condition the catalysts show enhanced activity since the hydrophobicity of the surface can tune by applying organic groups. In this regard, oxidation of cyclohexene was performed using hydrogen peroxide as oxidant in the present of tungstate based task–specific ionic liquids and silica–functionalized ammonium tungstate as green catalysts. The results indicate that adipic acid achieves in high yield with excellent selectivity.... 

The purpose of this study is to prepare a catalyst for copper nanoparticles that can be used in C-H activation processes in order to increase copper salt catalytic processes by converting it into a catalyst with characteristics of having recovery cycles, convenient separation and environmental friendliness and being in nano size. Consequently, copper nanoparticles are directly grafted onto graphene oxide, or using para-aminobenzoic acid grafted on graphene oxide. A copper nanoparticle catalyst was used in the reaction to activate the C(sp2)-H bonds of benzoxazole molecule and C-N bonds formation with secendary amines. Using the results of transition electron microscopy (TEM), scanning... 

In this thesis, the copper oxide - zinc oxide nanocomposite was synthesized and functionalized using 3-aminopropyltrimethoxysilane. The functionalized nanocomposite was characterized using X-ray Diffraction spectroscopy (XRD), Fourier Transform Infrared (FT-IR), X-ray Fluorescence Spectroscopy (XRF), Scanning Electron Microscopy (SEM) and Brunauer–Emmett–Teller (BET). Dye removal from synthetic wastewater was done in a batch system using functionalized copper oxide - zinc oxide nanocomposite as adsorbent. Direct red 23, direct red 80 and direct red 81 were used for preparation of synthetic wastewaters. The effects of operational parameters such as adsorbent dosage, initial dye concentration,... 

Additive manufacturing (Simply called A.M.) is a group of manufacturing technologies that is developing rapidly and is being used widely in some industries like car manufacturing, Aerospace and producing Biomedical devices, In a way that some researchers believe that A.M. methods will change the future of manufacturing. One of the most important A.M. techniques is the Selective Laser Sintering (SLS) method that is mostly used in industrial applications. A SLS machine has a lot of sub systems and mechanisms that have key role in the Laser Sintering process. One of the mechanisms of SLS machine is the Powder Dispensing mechanism that produce layers of unsintered powder as thin as 100 microns... 

In this thesis the graphene-based magnetic nanocatalyst was synthesized. The surface of this catalyst was cavered by silica and AgNPs. In addithion of simple sepration by magnetbar, yeild of reaction was promoted by surface modification. Catalyst structure was verified by transmission electron microscopy , scanning electron microscope, fourier transform infrared spectroscopy, X-ray diffraction and Energy dispersive spectroscopy.At the end catalytic activity was examined by oxidation reaction in persense of different alcohols. The oxidation of benzylic alcohol with electron withdrawing substituents was more difficult and the yield was lower, but electron donor substituents effect positively...