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Study possibilities of nanotechnology in cement composites
Kardošová, Romana ; Bodnárová, Lenka (referee) ; Hela, Rudolf (advisor)
The aim of this paper is to summarize and assess the possibility of using nanoparticles as additives in concrete. These particles have the ability to improve the mechanical and physical properties of cement composites or even gave them brand new ones. Industrial use is hampered by effective incorporation of nanoparticles into the matrix, the health and environmental risks and, last but not least, the financial costs. The experimental part of the thesis deals with the dispersing nanosilica and nanometakaolin particles in aqueous solution and their subsequent integration into the structure of cement mortar.
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Verification of the properties of concrete with carbon nanotubes
Kutová, Lenka ; Hela, Rudolf (referee) ; Bodnárová, Lenka (advisor)
This diploma thesis deals with monitoring the properties of concrete with carbon nanoparticles. The theoretical part describes properties of nanoparticles, their dosing and dispersion. In the practical part of the diploma thesis the physico-mechanical properties of the concrete with the addition of carbon nanotubes were determined after 7 and 28 days of aging. The frost resistance test was then determined after 100 cycles. All results were compared with the reference samples.
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Interlaminar fracture toughness of fiber reinforced plastics
Vodička, Vít ; Mališ, Michal (referee) ; Klement, Josef (advisor)
Cílem této diplomové práce je lépe porozumět konceptu únavového poškození damage tolerance zmapováním všech možných vlivů na lomovou houževnatost vláknového kompozitu s polymerní matricí. Toho je dosaženo provedením zkoušek za různých podmínek (např. změna parametrů měření, mód zatížení, pořadí vrstev a materiál) a monitorováním odlišností v šíření trhliny. Na základě dat získaných během těchto testů je určena lomová houževnatost. Potenciální rozdíly jsou zkonzultovány a porovnány s ostatními vzorky.
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High-grade concrete using nanoparticles
Labaj, Martin ; Bodnárová, Lenka (referee) ; Hela, Rudolf (advisor)
The aim of this paper is to summarize and assess the possibility of using nanoparticles as additives in high performance concrete. These particles have the ability to improve the mechanical and physical properties of cement composites or even gave them brand new ones. Industrial use, however, is hampered by several obstacles. In particular, it is the task of effective incorporation of nanoparticles into the matrix, the health and environmental risks and, last but not least, the financial costs. The experimental part of the work deals with the first-mentioned problem, namely with dispersing carbon nanotubes in aqueous solution and their subsequent integration into the structure of cement mortar.
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Use of nanotechnologies, especially CNT, in silicate composites
Jarolím, Tomáš ; Bodnárová, Lenka (referee) ; Martinec,, Petr (referee) ; Kalina,, Michal (referee) ; Hela, Rudolf (advisor)
Thesis theme were nanomaterials and its implementation to cementitious materials. Theoretical part has deal with description of carbon nanotubes types, their properties, production, ways of dispergation, nanotoxicity and CNT’s influence on silicate composites characteristics. Experimental part was divided to 5 stages. The first stages were focused on choosing appropriate carbon nanotubes and surfactants. In the next stage settings of US homogenizator were determinate (amplitude, US energy dosage, time). The part of US homogenizator setting process was observing influence of liquid environment characteristics (especially pH) on surface tension and particle distribution and influence of US energy on CNT walls damages through TEM. After dispergation parameters optimalization cement pastes were prepared and hydration temperature, hydration heat and viscosity were observed. Then testing specimens from cement mortar were prepared and tested form strength characteristics. Last stage was concrete production and their examination: compressive strength, flexural strength, static modulus of elasticity, dynamic modulus of elasticity, tensile splitting strength, depth of penetration of water under pressure, resistance of cement concrete surface to water and defrosting chemicals and determination of frost resistance of concrete. Samples with CNT addition had better strength characteristics and better resistance of penetration of water under pressure, water and defrosting chemicals resistance and frost resistance. Result of thesis is comprehensive study of CNT dispersion production and implementation CNT dispersion to concrete including testing specific concrete characteristics.
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Self-Sensing Properties of Metakaolin Geopolymer with Carbon Nanotubes under Compressive Loading
Mizerová, Cecílie ; Rovnaník, Pavel ; Kusák, Ivo ; Schmid, Pavel
Increased capability of alkaline activated binders to transfer the electric charge became an attractive issue in research related to multifunctional materials with self-sensing, self-heating and other progressive properties. This study is focused on self-sensing properties of metakaolin geopolymer mortars with 0.05 and 0.10% carbon nanotubes under repeated compressive loading. Specimens incorporated with copper electrodes were subjected to two different regimes of compressive loading with continuous monitoring of strain and electrical resistance. Both reference and modified geopolymer mortars have shown good response to applied loading, yet the differences in sensitivity and structural deformations were observed.
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Verification of properties of concretes with nanoparticles
Pacltová, Klára ; Hela, Rudolf (referee) ; Bodnárová, Lenka (advisor)
This diploma thesis deals with the influence of addition of carbon nanoparticles on cement composites. The theoretical part of the diploma thesis is focused on the research of information about carbon nanoparticles, more precisely about carbon nanotubes and graphene oxide. There are summarized methods of dispersing carbon nanotubes and their effects on cement composites. The practical part follows the theoretical part of the research. In the first phase, the correct technique of graphene oxide dispersion was verified. Subsequently, the effects of graphene oxide on the mechanical properties of cement mortars were verified. In the final phase of the diploma thesis, the knowledge gained from the previous part was verified on concrete samples.
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Use of nanotechnologies, especially CNT, in silicate composites
Jarolím, Tomáš ; Bodnárová, Lenka (referee) ; Martinec,, Petr (referee) ; Kalina,, Michal (referee) ; Hela, Rudolf (advisor)
Thesis theme were nanomaterials and its implementation to cementitious materials. Theoretical part has deal with description of carbon nanotubes types, their properties, production, ways of dispergation, nanotoxicity and CNT’s influence on silicate composites characteristics. Experimental part was divided to 5 stages. The first stages were focused on choosing appropriate carbon nanotubes and surfactants. In the next stage settings of US homogenizator were determinate (amplitude, US energy dosage, time). The part of US homogenizator setting process was observing influence of liquid environment characteristics (especially pH) on surface tension and particle distribution and influence of US energy on CNT walls damages through TEM. After dispergation parameters optimalization cement pastes were prepared and hydration temperature, hydration heat and viscosity were observed. Then testing specimens from cement mortar were prepared and tested form strength characteristics. Last stage was concrete production and their examination: compressive strength, flexural strength, static modulus of elasticity, dynamic modulus of elasticity, tensile splitting strength, depth of penetration of water under pressure, resistance of cement concrete surface to water and defrosting chemicals and determination of frost resistance of concrete. Samples with CNT addition had better strength characteristics and better resistance of penetration of water under pressure, water and defrosting chemicals resistance and frost resistance. Result of thesis is comprehensive study of CNT dispersion production and implementation CNT dispersion to concrete including testing specific concrete characteristics.
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Antibacterial and antiadhesive properties of carbon nanomaterials
Budil, Jakub ; Lišková, Petra (advisor) ; Zikánová, Blanka (referee)
Increasing interest in industrial and medical applications of carbon nanomaterial leads to the need to examine its interactions with living systems. Nanocrystalline diamond (NCD) films possess high mechanical and chemical stability which, together with its biocompatibility with human cells, enables applications in human body. Some of carbon nanoparticles possess strong antibacterial activity. In this work the effects of NCD with hydrogen, oxygen and fluorine termination deposited on glass and silicone on adhesion of gram-negative bacteria Escherichia coli K-12 in mineral medium is described and the impact of cultivation medium on effects of NCD films is compared. Prior the growth of the E. coli biofilm on NCD films, the method for quantification of biofilm using crystal violet staining and the method for biofilm cultivation in mineral medium were optimised. The properties of NCD film are independent on the base substrate. Hydrogen and fluorine terminated NCD films show antiadhesive properties only in mineral medium but not in complex medium. This is explained by formation of a conditioning film on the surface of the NCD film during cultivation in complex medium. On the other hand, O-NCD film supports bacterial adhesion in both cultivation media. Second part of this thesis is dedicated to carbon...
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