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polymerization
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Synthesis and Characterization of Polymer Nanofibers Modified by Using of Radiated Grafting for Adsorption of Molybdenum Ions from Aqueous Solution
, M.Sc. Thesis Sharif University of Technology ; Outokesh, Mohammad (Supervisor) ; Asadollahzadeh, Mehdi (Supervisor) ; Torkaman, Rezvan (Co-Supervisor) ; Torab Mostaedi, Meysam (Co-Supervisor)
Abstract
Molybdenum is one of the important elements of the intermediary metal with atomic number 42, which is used in various industries, but among the important uses of this metal in the nuclear industry, we can mention the presence of this element in the production of yellow cake as an impurity and also as a precursor for the production of radiopharmaceuticals. It is one of the impurities that remain in all stages of yellow cake production along with uranium, and the high presence of this element causes the centrifuges to become unbalanced during the injection of "U" "F" _"6" gas, and on the other hand, technetium, the main ingredient in the production of radiopharmaceuticals, It comes from the...
EPR Dosimetry based on Monte Carlo Method (Simulation and Measuring Dose with EPR Method)
, M.Sc. Thesis Sharif University of Technology ; Hosseini, Abolfazl (Supervisor) ; Mohammadzadeh, Mohammad (Co-Advisor)
Abstract
The Electron Paramagnetic Resonance(EPR) is a retrospective and accurate dosimetry method to measure irradiated-induced radical population in the matter for determination the induced dose in the matter. The dose uncertainties will be about 1 percent. in the first stage of the present research, the response of EPR system to a reference sample has been measured. Then, responses due to the other samples has been compared with it and the secondary sample dose has been calculated. The reference sample usually is alanine. Unlike the perturbation theory forecast,the EPR signal intensity response to dose for alanine is not linear. In this thesis, first, the alanine samples (with pellet form) have...
An Analytical Solution for the Polymeric Liner Collapse in Hyperbaric type IV Hydrogen Storage Vessels
, M.Sc. Thesis Sharif University of Technology ; Naghdabadi, Reza (Supervisor)
Abstract
Type IV high pressure vessels are composite vessels with a polymeric liner, which are the best choice for storing hydrogen in hydrogen vehicles. The defect of these vessels is the penetration of light hydrogen molecules in the polymeric liner and the composite part. When depressurization the vessel, these molecules cannot release from the polymeric liner and the composite part according to the emptying rate of the vessel. Thus, concentration of the hydrogen molecules in the polymeric liner becomes more than inside the vessel which leads to a pressure difference between the two sides of the polymeric liner that causes the liner collapse. In this research, the partial differential equation for...
Hydrodynamic Modeling and Swarm Control Microswimmers
, M.Sc. Thesis Sharif University of Technology ; Sayyaadi, Hassan (Supervisor) ; Mehdigholi, Hamid (Co-Supervisor)
Abstract
Nowadays, regarding the wide achievements in micro scale technology, it is possible to manufacture a micro robot. Micro swimmer have extensive applications in different fields especially in medical sciences. One of the most important problems of the micro robot is their propulsion system. The locomotion of microorganisms in fluids is ubiquitous and plays an important role in numerous biological processes. The physics of swimming governing life under the microscope is very different from the one we experience in the macroscopic world. This project is aimed at designing a propulsion system for a micro swimmer based on the swimming mechanism of the eukaryotic Spermatozoa. Simplicity to build is...
Fluids Flow Simulation in the Cell Influenced the Focal Adhesions
, Ph.D. Dissertation Sharif University of Technology ; Firoozabadi, Bahar (Supervisor) ; saidi, Mohammad said (Co-Advisor)
Abstract
In the present thesis, intracellular fluid flows have investigated for study cell motions. It is due to firmly relation between the cell motion and these flows. Generally, the cell firstly adheres to a surface, then, moves forward with the effects of the internal fluid flows. In this study, the cell structure is invided to two general parts; the front part of the cell and the cell body. The front part of the cell plays a essential roles in the cell motion, however, the cell body is considered as a extra cargo that is carried by the front of the cell. Therefor, in the present modellings, the front part is only considered. Here, using four different models for the front part of the cell, many...
Design, Fabrication and Control of a novel Polymeric Thermal Microactuator
, M.Sc. Thesis Sharif University of Technology ; Alasty, Aria (Supervisor) ; Salarieh, Hassan (Supervisor)
Abstract
Systems composed of electrical and mechanical elements in micrometer scale are called microelectromechanical systems which are commonly fabricated on silicon substrates. These systems are in connection with environment by the means of sensors and actuators. Thermal microactuators as one of the most applicable actuators produce force and displacement on the basis of thermal expansion.Recently, by the advent of some polymers compatible with microfabrication methods such as SU8 and due to their remarkable thermal properties,polymeric thermal microactuators are attracting more attention in a way that polymeric type of almost every predesigned thermal microactuators are fabricated and much...
Design, Dynamic Analysis and Fabrication of a Ring-like Robot with Deformable Shell
, M.Sc. Thesis Sharif University of Technology ; Alasty, Aria (Supervisor)
Abstract
In this research application of Ionic Polymer Metal Composite (IPMC) as actuator in a deformable ring capable of locomotion is studied. Such a deformable ring moves as a result of gravitational force acting on its body when its shape changes. A deformable robot made of IPMC can be used in exploration, search and rescue missions in future, where using conventional robots with rigid bodies and actuators is impossible. Large deformation induced by small stimulating voltage, low stiffness and the sensing characteristics that in future work can be used in feedback control make IPMC a good choice for such an application. In this work first a model for IPMC is introduce that can be used in...
Introducing a New Boundary Condition Method in Dissipative Particle Dynamics and Simulation of Dilute Polymer Solution
, M.Sc. Thesis Sharif University of Technology ; Saidi, Mohammad Saeid (Supervisor) ; Saidi, Mohammad Hassan (Supervisor) ; Shafiee, Mohammad Behshad (Supervisor)
Abstract
Dissipative particle dynamics (DPD) is an emerging mesoscopic computational method in which the interparticle forces arise because of coarse-graining at the molecular level. In the asymptotic limit of large length scales, the governing equations of continuum are reproduced, as demonstrated in this work. This method of simulation has the capability of simulating larger order of time and space in compare with dynamic molecular method. One of the important applications of DPD is simulating the dilute polymer solution. In this project, we developed a general code to simulate dilute polymer behavior which consists of polymeric forces and different types of usual DPD boundary conditions. This code...
Synthesis and Characterization of Nanofibrous Polymeric Composite Containing Two-dimensional MXene and Capable of Drug Release for Tissue Engineering Applications
, M.Sc. Thesis Sharif University of Technology ; Simchi, Abdolreza (Supervisor)
Abstract
Nowadays, biocompatible composites are being utilized as scaffolds supporting cell growth promotion and features with the aim of organs regeneration or substitution based on tissue engineering principals. Moreover, in order to improve bioscaffolds features and function, various two-dimensional composite fillers have been under investigation; for instance, Graphene, Boron nitride, Metal dichalcogenides and oxides and black phosphorous and also electrospinning is mentioned as one of the most compatible and conventional processes of scaffold design that is also the main method of fabrication in this study. In addition, it should be pointed that biocompatible polymers and particularly natural...
The Effect of Graphene Nano-Sheet on Antioxidant Stability in Polyethylene Pipes
, M.Sc. Thesis Sharif University of Technology ; Pircheraghi, Gholamreza (Supervisor)
Abstract
PE pipes and specially PE100 are commonly used for the transportation of drinking water, transferred water was mostly disinfected by disinfectants such as chlorine, chlorine dioxide and chloramine. Long-term contact with water containing disinfectants led to morphological and mechanical changes and followed by oxidative degradation and failure. Antioxidants are stabilizers which are used in PE pipes to postpone oxidation and increase the durability of these pipes. Migration of antioxidants is possible during the terms of service, in this case antioxidants can be washed by water and left the pipe. As a result, the loss of antioxidants decreases the stability of pipes and leads to oxidative...
PLA/PEG/HAp Nano-Composites as Drug Carriers
, M.Sc. Thesis Sharif University of Technology ; Frounchi, Masoud (Supervisor)
Abstract
In recent years, the tendency to use biodegradable and biocompatible polymer nanoparticles for drug delivery applications has been increasing, the reason for this being the possibility of precise control of the drug release rate, ease of use, and no need for external Surgery after the release of the drug, increases the therapeutic efficiency of the drug and reduces the side effects with its precise transfer. In this research work, drug carrier nanocomposites were prepared from polylactic acid (PLA), polyethylene glycol (PEG) and hydroxyapatite (HAp) and for the controlled release of ciprofloxacin (CIP). It was used to treat bone infections. The drug loading efficiency for nano-carriers was...
Synthesis and Investigation of The Possibility of Using Hydrolyzed Acrylamide Copolymers Containing Hydrophobic Monomers for Water Purification (Flocculation)
, M.Sc. Thesis Sharif University of Technology ; Ramazani Saadatabadi, Ahmad (Supervisor)
Abstract
to achieve a stable elimination of colloidal suspended particles, polymer flocculants such as polyacrylamide and its derivative have been more used. To improve the performance of removing turbidity, reducing settling time, and better dewatering from sediments, hydrophobic styrene monomer copolymerized with acrylamide monomer. In this study the copolymer of acrylamide and styrene was synthesized by inverse emulsion polymerization, then this copolymer undergoes hydrolysis to form anionic groups on the polymer backbone. FT-IR, H NMR, and TGA analyses were carried out to investigate the structure of the copolymer. To evaluate flocculation, turbidity tests, zeta potential, and sedimentation rate...
Synthesis and Evaluation of Poly(lactic Acid)/Polyurethane Nano-composites based on Cellulose Nano-particles, with Biomedical Applications
, M.Sc. Thesis Sharif University of Technology ; Shojaei, Akbar (Supervisor) ; Salkhi Khasraghi, Samaneh (Co-Supervisor)
Abstract
Shape memory polymers have the potential to use in the field of biomedical applications. In this research, polyurethane structures have been synthesized based on the Diol mixtures, consisting of polycaprolactane diol (PCL-diol) and poly (lactic acid) diol (PLA-diol). Aim of reasearch is about evaluating poly (lactic acid) effect in structure of the polyurethane. At the same time, cellulose nanocrystals (CNC) have been added to polymer matrix to improve properties. The synthesis of acrylated polyurethane, included the synthesis of polyurethane acrylate prepolymer. Next, this prepolymer has been cured by adding the reactive diluent and some polyol. The cured systems were investigated, finally,...
Preparation of Acrylamide Copolymers Containing Highly Hydrophobic Monomers and Study on Their Drag Reduction Properties
, M.Sc. Thesis Sharif University of Technology ; Ramazani Saadatabadi, Ahmad (Supervisor)
Abstract
With the rapid increase of energy consumption, energy problem has been a global issue, which must be faced with and solved. One way to prevent energy consumption is to reduce drag in the flow inside the pipes by using polymer additives; Because the Transportation of liquids using pipeline technology has its limitations, since turbulent flow inside the pipe involves a loss of energy. The net effect of this is that increasing the energy applied to the flow does not increase the flow rate. For this purpose, copolymers and terpolymers of hydrophilic acrylamide monomers along with hydrophobic styrene and hydrophilic maleic anhydride monomers were synthesized by reverse emulsion polymerization...
Selective Transfection of Smart Polymeric Nanoparticles Into Reactive Astrocytes in Animal Model of Spinal Cord Injury
, Ph.D. Dissertation Sharif University of Technology ; Frounchi, Masoud (Supervisor) ; Mashayekhan, Shohreh (Co-Supervisor) ; Kiani, Sahar (Co-Supervisor)
Abstract
In this study, chitosan-based nanoparticles were prepared due to their biocompatibility, availability, high loading capacity of drug, stimulus responsive behavior and the presence of active functional groups. Chitosan was chemically functionalized with reactive oxygen species (ROS)-responsive moiety to respond to the oxidative stess and endosomal pH in nerve injuries. To prepare nanoparticles, functinalized chitosan ionically gelated with pH-responsive polyanions with ROS-scavenging properties such as polyacrylic acid and hyaluronic acid. Then, pH- and ROS-responsive nanoparticles were used for selective transfection into reactive astrocytes and axonal regeneration in spinal cord injuries....
The Investigation of Thermal and Rheological Properties of Hydrophobically Modified Polymer of Acrylamide
, M.Sc. Thesis Sharif University of Technology ; Ramazani Saadatabadi, Ahmad (Supervisor)
Abstract
Among chemically enhanced oil recovery (CEOR) methods, polymer flooding has the highest commercial potential. However, the most widely used conventional polymers such as partially hydrolyzed polyacrylamide (HPAM) are not applicable for high-temperature and high-salinity reservoirs. To overcome above-mentioned problems, in this work, a series of water-soluble hydrophobically modified polymers (HMPs) nanostructures comprising 2-vinyl naphthalene (hydrophobic monomer) has been produced by freestyle method (without Surfactant), micellar (with Surfactant). The size of the particles was investigated using scanning electron microscopy (FE-SEM) and optical scattering (DLS). Results from FT-IR...
Experimental Investigation of Fractures’ Water Shut-off in Low Salinity Water Injection Using Preformed Particle Gels
, M.Sc. Thesis Sharif University of Technology ; Fatemi, Mobin (Supervisor) ; Ghazanfari, Mohammad Hossein (Supervisor)
Abstract
As the reservoir matures, especially in fractured reservoirs, oil production is usually accompanied by the production of some unwanted water. Water production causes environmental problems and imposes high costs on the production system, including the cost of separating water and oil, corrosion of facility, and sometimes, leading to abandoning well. One way to solve this problem is to use gels as a blocking agent. Today, preformed particle gels are used as an alternative to in situ gels, which can solve some issues of in-situ gels, such as uncertainty in gelling time and penetration depth.This research comprises three main parts. In the first part, four samples of preformed particle gels...
Manufacture of Smart Drug Delivery System with UCST Polymers
, M.Sc. Thesis Sharif University of Technology ; Ramazani, Ahmad (Supervisor)
Abstract
Smart heat-sensitive polymers play a unique role in drug delivery systems due to reversible behavior in response to environmental changes, especially temperature changes. Among the heat-sensitive polymers, UCST polymers due to their specific behavior and very little-known polymers with this feature are the subject of many new researches. In the present study, New designed temperature-sensitive polymers with UCST capability based on acrylamide and vinyl acetate were synthesized. These copolymers were synthesized in different percentages of acrylamide by free radical polymerization in solution conditions. All polymers compounds were characterized by H-NMR, FT-IR, DSC and GPC measurements. The...
Facilitation of Transscleral Drug Delivery
, M.Sc. Thesis Sharif University of Technology ; Abdekhodaie, Mohammad Jafar (Supervisor) ; Seifkordi, Aliakbar (Supervisor) ; Ahmadieh, Hamid (Co-Supervisor)
Abstract
In the present research the methods and challenges to ocular drug delivery have been investigated with more emphasis on ocular diseases that do not have any approved treatment. Periocular route is a promising alternative to the common routes of ocular drug delivery especially for treatment of posterior eye diseases. Based on barriers for efficient drug delivery to the eye, magnetic drug targeting revealed to be influential to eliminate some obstacles of this route which has not been worked before. It is hypothesized that the particles can pulled into the eye or will be trapped inside the sclera tissue or even if it is not happened, they can stay behind the sclera and magnetic force can...
Fabrication and Properties Investigation of Acrylamide Terpolymer Containing Silica Nanoparticles to Use in Drilling Fluids
, M.Sc. Thesis Sharif University of Technology ; Ramazani, Ahmad (Supervisor) ; Haddadi, Arash (Co-Supervisor)
Abstract
Most used polymers, such as hydrolyzed polyacrylamide, are not able to withstand high levels of salinity and high temperature of the reservoirs. To overcome these problems, in this project, new types of microstructures based on modified acrylamide with hydrophilic groups (malic anhydride monomer) and hydrophobic groups (styrene monomer) using inversible mini-emulsion were synthesized. The structure of the synthesized terpolymer was investigated using methods of FT-IR and 1H NMR. The micro-structure and the particle-size of the terpolymer particles were studied with the scanning electron microscopy (FE-SEM) and differential light scattering (DLS) method and the results showed that the average...