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Vinyl prepolymers - methods of preparation and application
Černý, Miroslav ; Petrůj, Jaroslav (referee) ; Kučera, František (advisor)
The theoretical part of this thesis is focused on bulk radical polymerization of styrene, methylmethacrylate, vinyltoluene and paramethylstyrene. It summarizes actual informations about kinetics and performance possibilities of bulk polymerization. Experimental part deals with polystyrene prepolymers preparation by bulk polymerization. The aim is to find optimal conditions for prepolymers preparation. Prepolymers should be usable for subsequent polymerization nearly up to 100% conversion. Conversion values were gravimetrically determined and molecular weights were obtained by viskosity measurements, which were realized by Ubbelohde viscometer. In the experimental part, there were performed simulations targeted on conversion dependence on time. The purpose was a prediction of monomer conversion at a given time during polymerization. Differences between reality and simulation were low in most of cases and the found form of kinetic behavior calculations provides satisfying results. In the conclusion of this thesis was suggested a new procedure for polystyrene prepolymers preparation.
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Gel polymer electrolytes with nanoparticles
Szotkowski, Radek ; Sedlaříková, Marie (referee) ; Jahn, Michal (advisor)
This master‘s thesis concerns gel polymer electrolytes formed on a methyl methacrylate base with selected types of nanoparticles. In the thesis are also analyzed the methods for measuring electrochemical properties. The practical portion deals with sample preparations of gel polymer electrolytes with different contents of alkaline salt in a solvent, creating gels with different nanoparticle content and comparing gel polymer electrolytes polymerized with heat and UV radiation. The thesis deals with the evaluation of these samples from the viewpoint of electrical conductivity and potential windows as well as thermal analysis of selected samples.
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Gel Polymer Electrolytes Based On Ethylene Glycol Dimethacrylate And Their Electro-Chemical Characterization
Veselkova, Iuliia
The electrochemical properties of cross-linked gel polymer electrolyte based on ethyleneglycol dimethacrylate are investigated. Impedance spectroscopy was used for studying the mode ofelectrical conductivity in prepared gel electrolytes. A study of electrochemical stability was providedusing linear sweep voltammetry. The increasing amount of ethylene glycol dimethacrylateshows the decreasing of electrical conductivity. The presence of cross-linking agent affects not onlythe electrochemical properties but also the mechanical properties.
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Study Of Electrochemical Properties Of Gel Polymer Electrolyte Based On Tetraethyl Ammonium Salt
Veselkova, Iuliia
In this study, gel polymer electrolytes based on tetraethyl ammonium tetrafluoroborate salt (TEA BF4) were prepared by UV-light polymerization technique. The effect of adding TEA BF4 in different concentrations on electrochemical and mechanical properties were studied. Ionic conductivity and potential window were measured by impedance spectroscopy and linear voltammetry methods. The results indicate how salt concentration affects electrochemical properties of gel polymer electrolytes.
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Gel Polymer Electrolytes Based On MMA With Ionic Liquids
Jahn, Michal
Gel polymer electrolytes are perspective electrolytes for new types of Li-ion batteries today. The properties respectively advantages of these gels can be used also in other fields of electrochemistry. Very promising combination can be electrochemically stable polymers and ionic liquids, which are substances that consist of an organic cation and an inorganic or organic anion, with a melting point below 100 °C. Main advantages of ionic liquids are high ionic conductivity, inflammability and excellent electrochemical stability. These ionic liquids may be suitable for new lithiumion batteries and supercapacitors, especially where the required higher thermal stability. In this paper, I will present fundamental characteristics of gel polymer electrolytes with ionic liquids.
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Electrochemical Properties Of Gel Polymer Electrolytes Modified Flame Retardants
Veselkova, Iuliia
This paper deals with preparation of gel polymer electrolytes modified by flame retardants based on methyl methacrylate. The aim of this work was to investigate the effect of thermal polymerization method on electrochemical properties such as ionic conductivity and potential window of gel polymer electrolytes. For measuring electrochemical properties, impedance spectroscopic techniques and linear voltammetry were used. Results indicate the dependence of ionic conductivity on the amount of flame retardant.
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An Influence Of Conductive Component Composition
On Gel Polymer Electrolyte Properties
Veselkova, Iuliia
This paper deals with searching of gel polymer electrolytes, which can be used as replacement of liquid electrolyte in lithium batteries and supercapacitors. The research reports how different salts and solvents affect mechanical, electrochemical and electrical properties of gel electrolytes. For measurement electrical and electrochemical properties were used methods such as impedance spectroscopy and cyclic voltammetry to calculate electrical conductivity and potential window respectively. Results indicate which chemical composition of gel polymer electrolyte theoretical can be work in electrochemical cell instead of liquid electrolyte.
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Gel Polymer Electrolytes for Use in Lithium-ion Batteries
Jahn, Michal
Gel polymer electrolytes are perspective electrolytes for new types of Li-ion batteries today. The properties respectively advantages of these gels can be used also in other fields of electrochemistry. The gel polymer electrolyte is composed of a conductive component (liquid electrolyte) and the polymer component (methacrylate). In this paper I present fundamental characteristics of gel polymer electrolytes. This paper presents a principle of gel polymer electrolytes, fundamental measurement and their evaluation. I present the techniques of measurement and preparation of this gel polymer materials. Potentiostatic impedance, linear sweep voltammetry, cyclic voltammetry and galvanostatic charge/discharge techniques were used for characterization of the samples.
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Gel polymer electrolytes with nanoparticles
Szotkowski, Radek ; Sedlaříková, Marie (referee) ; Jahn, Michal (advisor)
This master‘s thesis concerns gel polymer electrolytes formed on a methyl methacrylate base with selected types of nanoparticles. In the thesis are also analyzed the methods for measuring electrochemical properties. The practical portion deals with sample preparations of gel polymer electrolytes with different contents of alkaline salt in a solvent, creating gels with different nanoparticle content and comparing gel polymer electrolytes polymerized with heat and UV radiation. The thesis deals with the evaluation of these samples from the viewpoint of electrical conductivity and potential windows as well as thermal analysis of selected samples.
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Vinyl prepolymers - methods of preparation and application
Černý, Miroslav ; Petrůj, Jaroslav (referee) ; Kučera, František (advisor)
The theoretical part of this thesis is focused on bulk radical polymerization of styrene, methylmethacrylate, vinyltoluene and paramethylstyrene. It summarizes actual informations about kinetics and performance possibilities of bulk polymerization. Experimental part deals with polystyrene prepolymers preparation by bulk polymerization. The aim is to find optimal conditions for prepolymers preparation. Prepolymers should be usable for subsequent polymerization nearly up to 100% conversion. Conversion values were gravimetrically determined and molecular weights were obtained by viskosity measurements, which were realized by Ubbelohde viscometer. In the experimental part, there were performed simulations targeted on conversion dependence on time. The purpose was a prediction of monomer conversion at a given time during polymerization. Differences between reality and simulation were low in most of cases and the found form of kinetic behavior calculations provides satisfying results. In the conclusion of this thesis was suggested a new procedure for polystyrene prepolymers preparation.
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