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New gel electrolytes
Sumka, Martin ; Jahn, Michal (referee) ; Sedlaříková, Marie (advisor)
This master´s thesis deals with the properties of gel polymer electrolytes, brief characteristics of other types of electrolytes and materials that are used for preparing polymer electrolytes. The thesis explains the use of the gel electrolytes in practice, the current conduction in the electrolytes and the properties of ionic liquids, and flame retardants. This thesis also focuses on methods of measurement of mechanical properties of gel polymer electrolytes. The practical part is focused on preparation of methacrylate gel electrolytes and their modifications with the use of flame retardant - triethyl phosphate (TEP) and ionic liquid - 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (Emim TFSI). In this part there are evaluations of their potential funcionality (potential window) and specific conductance conductivity using the method LSV (linear sweep voltammetry) and impedance spectroscopy. The practical part also includes a thermal analysis of selected samples by TGA, DTA and EGA methods.
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Proposition of grounding enhancing cement composite mixture
Sochor, David ; Bydžovský, Jiří (referee) ; Drochytka, Rostislav (advisor)
The bachelor thesis deals with the design of a conductive cement composite grounding mixture for protection of building structures in areas with low conductivity. The theoretical part is mainly focused on summarizing the knowledge of the current protection of buildings against lightning and overvoltage. The study includes knowledge in the field of conductive building materials and aims to present the design of a cement composite mixture to improve grounding. Choosing the right raw materials to achieve electrical conductivity. A maintenance-free material has been developed, no humidity needed material while maintaining conductivity. The work it examines the possibilities of using industrial wastes as secondary raw materials. The conclusion focuses on laboratory testing of newly developed materials, summary and discussion of the results. With the developed samples, the resistivity was greatly reduced. The positive effect of ferric dust and carbon particles has been demonstrated.
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Measurement of insulation and dielectric properties of water.
Žvátora, Jaroslav ; Starý, Jiří (referee) ; Špinka, Jiří (advisor)
This bachelor thesis deals about dielectric and insulation properties of water. It describes the structure of water, hydrogen bonds. It explains primary physical and chemical properties of water and then it describes parameters of water such as dynamic viscosity, conductivity, surface pension, loss factor, polarization. Part of the work is practical section, which deals measurements of water and shows primary dependence such as capacity dependence on frequency or loss factor on frequency.
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The electrical properties of modified ionic liquids
Kulhavý, Miloslav ; Libich, Jiří (referee) ; Máca, Josef (advisor)
This thesis deals with ionic liquids and use of ionic liquids as electrolytes in lithium-ion batteries. Thesis describes basic characteristics of secondary electrochemical cells and characteristics of ionic liquids. Thesis also describes modifications and measurement of ionic liquids. Thesis also presents the results of measurement conductivity and potential window of modified ionic liquids.
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Sensoric properties of organic N-type semiconductors and their air stability
Saska, Pavel ; Vala, Martin (referee) ; Salyk, Ota (advisor)
Hydrogen has been for some time discussed as a successor to fossil fuels whose stocks are constantly running low. One of the crucial requirements for the possible usage of hydrogen as an energy carrier is our ability of reliable detection. In context with development of organic electronics there occurred a possibility to use derivatives of diketopyrrolopyrroles as sensing materials of hydrogen sensors. Derivatives of diketopyrrolopyrrole are organic pigments that behave as semiconductors. Their analogues with pyridyl side group are due to free electron pairs of nitrogen atoms sensitive to hydrogen. The problem of organic N-type semiconductors is in general their instability on the air. This thesis is focused on testing of hydrogen sensors with active layer made from derivatives of diketopyrrolopyrrole and judging their stability on the air.
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Self-sensing SPM probes for measuring electrical properties of materials
Očkovič, Adam ; Vařeka, Karel (referee) ; Pavera, Michal (advisor)
The bachelor's thesis is focused on the modification of probes with an integrated sensor usable for measuring conductivity characteristics of surfaces in atomic force microscopy. The first part presents the theory concerning atomic force microscopy, conductivity measurement and deposition using an ion beam. Furthermore, the method of production and limitation of the use of electrically conductive probes with optically read deflection is described. The practical part presents the main problems of probes with integrated sensors in conductivity measurements. Furthermore, the modification of the probes themselves, the measurements made with these probes and suggestions for improving the properties of the probes are described.
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Operation and optimization of a capacitive deionization unit
Vespalec, Jan ; Mergl, Václav (referee) ; Repková, Martina (advisor)
This bachelor thesis is focused on the extension of the information available so far on capacitive deionization within the framework of research activities in the field of separation methods. In the theoretical part, the laws of deionization, factors influencing the course of deionization, possible configurations of the capacitive deionization model, electrode corrosion issues, practical applications and future developments of capacitive deionization are discussed. The experimental part describes the capacitive deionization unit located at the FCH BUT, the procedure of electrode replacement, calibration of pH and conductivity probes and the optimal setting of factors influencing the course of deionization. In this bachelor thesis, a series of measurements were carried out to find the optimal setting of the unit.
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The heat transfer medium in heating systems
Michalíčková, Iveta ; Blasinski, Petr (referee) ; Počinková, Marcela (advisor)
Theme of diploma thesis is the heat transfer medium in heating systems. The thesis is departed to three parts. In the first part, there is a theoretical solution of heat transfer mediums. In the second part, there is a calculation solution of the project. Project solves heating of the apartment building. There are two variants of heating source and water treatment. Those variants are compared. The last part is experimental part. Theme of the experiment is quality of heating water in heating systems.
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Electrotransport properties of the nanostructures fabricated by the FIB
Ostřížek, Petr ; Kolíbalová, Eva (referee) ; Urbánek, Michal (advisor)
The aim of this work is fabrication of nanostructures and measurement of their electrotransport properties. There are two different methods used for fabrication - electron beam lithography with sputtering of thin films and focused ion beam with deposition from gas phase. I-V characteristic was measured for characterisation of as prepared nanostructures - wires. Material of wires prepared by using of electron beam lithography was permalloy - an alloy of iron and nickel. Second types of wires prepared by using of chemical vapor deposition induced by focused ion beam was platinum based.
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