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Polymeric nanocomposites - preparation methods
Černý, Miroslav ; Žídek, Jan (referee) ; Kučera, František (advisor)
Literature search of bachelor thesis was focused to methods of CaCO3 nanoparticles preparation, surface modification and PS/CaCO3 nanocomposites processing. Experimental part was based on two methods of PS/CaCO3 nanocomposites preparation: emulsion and bulk technique of styrene radical polymerization in presence of CaCO3 and by compounding CaCO3 with PS in Brabender mixer at 220 °C. Prepared samples were observed using electron microscope.
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Structure and Properties of Collagen/HAP Nanocomposite Networks
Kopuletá, Ema ; Lehocký,, Marián (referee) ; Amler,, Evžen (referee) ; Jančář, Josef (advisor)
Polymerní biomateriály jsou jedním ze současných populárních témat vzhledem k možnosti potenciální aplikace v tkáňovém inženýrství a řízeného dávkování léčiv v organismech. Kolagen je jako jeden z nejčastěji se vyskytujících proteinů zvláště zajímavý díky svým rozmanitým vlastnostem bez imunoreakce organismu příjemce. Tato práce je zaměřena na samouspořádávací procesy, kinetiku, obecné zákonitosti řídící proces samouspořádání a mechanické vlastnosti kolagenních roztoků. Dále je zkoumán efekt hydroxyapatitových nanočástic na samouspořádávání kolagenu a mechanické vlastnosti výsledných nanokompozitních hydrogelů. Jsou objasněny možné mechanismy interakcí mezi kolagenem I a hydroxyapatitem spolu s popisem vývoje struktury a vlastností na různých úrovních struktury. Byly měřeny a molekulárně interpretovány závislosti viskoelastických veličin na smykové rychlosti spolu s viskoelastickým chováním. Dále byla studována struktura kolagenních scaffoldů a určen vliv HAP a síťování. Závěrem byly diskutovány výsledky v souvislosti s jejich aplikovatelností v tkáňovém inženýrství chrupavek tvrdých tkání a v regenerativní medicíně.
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Clay minerals in polymeric materials
Zaťko, Petr ; Sluková, Michaela (referee) ; Krmíček, Lukáš (advisor)
The bachelor thesis deals with the clay minerals as fillers in polymer materials and their polymer/clay nanocomposites. The thesis brings an introduction to the structure of polymers and clay minerals and their application in polymer materials. The practical part of the thesis deals with testing the diffusivity of CO2 through the film made of recycled polyvinyl butyral with fillers Nanofil®5, Dellite® 67 and Cloisite® 93A and their comparison with reference samples from recycled PVB without added fillers and commercial films of extruded PVB.
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Study of electric properties of nanocomposites
Libra, Miroslav ; Rozsívalová, Zdenka (referee) ; Polsterová, Helena (advisor)
The present master´s thesis deals with the electrical properties of nanocomposite materials. Samples for the experiment are made epoxi resin and oxides TiO2 and Al2O3 as nanofillers in different percent performace. The samples nanocomposites are measured temperature dependence of the resistivity inside, dissipation factor and relative permittivity. It discusses the effect of the filler on the resulting electrical properties of the polymer.
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Removing of organic dyes from water using polyacrylamide hydrogel nanocomposites
Špalová, Anna ; Klusoň, Petr (advisor) ; Krystyník, Pavel (referee)
The unavailability and pollution of water resources have become significant global challenges. Hydrogels composed of cross-linked polymers have emerged as advanced adsorbents for wastewater treatment, owing to their convenient handling and high efficiency. By incorporating appropriate components into the hydrogel structure, the affinity of a specific pollutant to the hydrogel can be modified. Consequently, the resulting hydrogel nanocomposite can display enhanced adsorption capacity, specific selectivity, and other desirable properties. In this thesis, the efficiency of polyacrylamide hydrogel nanocomposites in the removal of organic dyes from water was investigated. Various composites were synthesized, incorporating graphene, kaolin, and laponite. The composition of these composites varied, employing different ratios of monomer to water and monomer to additive. The physicochemical properties of the synthesized hydrogels and their nanocomposites were examined. It was observed that the nanocomposites displayed reduced water-holding capacity compared to pure polyacrylamide hydrogels. The inclusion of additives led to a decrease in nanocomposite rigidity for graphene, minimal alteration in the case of kaolin, and an increase in rigidity for laponite. The compressibility modulus of the samples ranged...
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Personal exposure measurement during dental nanocomposite grinding
Ždímal, Vladimír ; Ondráčková, Lucie ; Ondráček, Jakub ; Schwarz, Jaroslav ; Bradna, P. ; Roubíčková, A. ; Pelclová, D. ; Rössnerová, Andrea
The purpose of this study was to measure the personal exposure of each participant of the study and to compare the results with those of static monitoring. Personal nanoparticle sam-plers (PENS), which can simultaneously detect both nanoparticles (PM0.1) and respirable parti-cles (PMA), were used to determine personal exposure (Tsai et al., 2012). Area monitoring in-cluded measurement of mass concentrations using the Berner Low Pressure Impactor (BLPI 25/0.018 /2, Hauke GmbH, Gmunden, Austria) and the Low Volume Sampler (LV5, Sven Leckel Ingenieurbüro GmbH, Germany). The number concentrations and their size distributions were measured with the Scanning Mobility Particle Sizer (5MP5 3936, T5I Inc., USA) and the Aerody-namic Particle Sizer (APS 3321, TSI Inc., USA). Measurements with all of the above- mentioned instruments were performed in four shifts with six participants per shift. Each participant milled for 10 minutes and then remained in the room until the group finished the session, so the total exposure lasted about 70 minutes. Due to the high content of filler nanoparticles, the nanocom-posite Filtek Ultimate (body A2, 3M ESPE, USA) was selected for these measurements.
Plný tet:  PDF
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Biomarkers of Oxidative Stress and Inflammation in Researches Exposed to Nanoparticles by Inhalation During the Handling of Nanocomposites.
Pelclová, D. ; Ždímal, Vladimír ; Schwarz, Jaroslav ; Komarc, M. ; Vlčková, Š. ; Fenclová, Z. ; Lischková, L. ; Dvořáčková, Š. ; Rössnerová, Andrea ; Rössner ml., Pavel
At present, little is known about the health effects in the workers processing nanocomposites. In our study, 20 researchers (41.8 +/- 11.4 y/o), handling nanocomposites for 17.8 +/- 10.0 years were examined pre-shift and post-shift, together with 21 controls (42.7 +/- 11.5 y/o). Biomarkers of oxidative stress derived from lipids, nucleic acids, proteins and markers of inflammation were analyzed in the exhaled breath condensate (EBC). Aerosol exposure was monitored during three nanoparticle generation operations: smelting, welding and nanocomposite machining. Mass concentrations during these operations ranged from 0.120 to 1.840 mg/m(3), and median particle number concentrations from 4.8x10(4) to 5.4x10(5) particles/cm(3). Nanoparticles accounted for 40 to 95 % of particles, with Fe and Mn prevailing. Significant elevations were already seen in most oxidative stress markers and in several inflammation markers in the pre-shift samples relative to the controls. Significant associations were found between working in nanocomposite synthesis and the majority of EBC biomarkers. Chronic bronchitis was more frequent in researchers. A minor, but significant post-shift decrease of lung function parameters was found. We conclude that workers in nanocomposite synthesis may be at risk of developing airway disorders with time. From all the markers analyzed in EBC, the following markers were most robust and could be recommended for preventive examinations: 8-hydroxy-2-deoxyguanosine (8-OHdG) and 5-hydroxymethyl uracil (5-OHMeU) from nucleic acids, o-tyrosine (o-Tyr) and 3-nitrotyrosine (3-NOTyr) from proteins, and malondialdehyde and aldehydes C6-C13 from lipids. Among the markers of inflammation, tumor necrosis factor (TNF) and leukotriene B4 appeared to be the most useful.
Plný tet: PDF
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Antimicrobial properties of photo-polymerized 3D printed nanocomposites
Matonohová, Zuzana ; Sevriugina, Veronika (referee) ; Lepcio, Petr (advisor)
This diploma thesis deals with the preparation and characterization of nanocomposites suitable for 3D printing by masking stereolithography (MSLA) and emphasis on the antimicrobial properties of prepared nanocomposites. The theoretical part of the work is devoted to research on additive production and 3D printing, materials suitable for 3D printing using the MSLA method and nanocomposites. The experimental part of the work then deals with the preparation of individual composites containing nanoparticles (ZnO, AZO, TiO2 and carbon nanotubes) and their subsequent testing. The printability of the material was monitored by Jacobson working curves and differential scanning photocalorimetry (photo-DSC), then the structure of the composite was evaluated by Fourier-transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA), mechanical properties were monitored by dynamic-mechanical analysis (DMA) and tensile tests. The main point of this work were antimicrobial tests, which were performed on printed composite samples and on the nanoparticles themselves.
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Ultrathin films deposited by means of magnetron sputtering and their characterization
Petr, Martin ; Kylián, Ondřej (advisor) ; Straňák, Vítězslav (referee) ; Tichý, Milan (referee)
Presented work is focused on the deposition and characterization of thin and ultrathin plasma polymer films, then also on the preparation of nanocomposites metal/plasma polymer. The characterization of plasma polymer films was partly done in-situ without exposing the samples to the atmosphere. The thickness of prepared films was measured by spectral ellipsometry, the chemical composition was measured by XPS. The morphology and optical properties of deposited films were measured ex-situ. It is shown that during the initial stages of growth the properties of plasma polymer films depend on their thickness and also on the material of the substrate. Many interesting applications were explored for prepared nanocomposites metal/plasma polymer. They can be used as superhydrophobic coatings, gradient coatings, substrates for Raman spectroscopy or as antibacterial coatings. Moreover, special optical properties of prepared nanocomposites were studied in detail. Presented work has an experimental character.
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Self-assembling hybrid nanomaterials
Rodzeń, Krzysztof ; Strachota, Adam (advisor) ; Svoboda, Jan (referee) ; Matějíček, Pavel (referee)
Organic-inorganic polymer hybrids containing butyl stannoxane dodecamer cages (Sn_POSS) as nano-building blocks were prepared and investigated. Sn_POSS was employed as a linear, crosslinking or non-bonding molecularly blended unit. For this purpose, it was synthesized with two acrylamido, primary- or secondary amino, or with two additional non- functional groups, which were attached via ionic-bonded sulfonate substituents. The nano- building block was then incorporated in matrices such as PS, PAOS, PETA, PEMA, PHEMA and PPO-based epoxies (the latter with different mesh sizes). Sn_POSS reinforces the studied matrixes by filler-filler interactions (self-assembly to nano-domains). Specific interactions of the ionic bonds of Sn_POSS with suitable pendant groups of the matrixes also can generate reinforcement and suppress filler aggregation. Moreover, the Sn_POSS can undergo several types of chemical reactions like heat-induced oligomerization, dissociation of the ionic substituents, acidolysis of the Sn-butyl bonds, as well as radical reactions of the latter. The influence of ionically bonded cages on the hybrids' morphology, as well as their ability of dissociation and short-distance migration in the polymer network at elevated temperature, was evaluated by TEM, IR and NMR analyses. The mechanical...
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