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Machinable bioceramic foams prepared by gelcasting method
Šťastný, Přemysl ; Částková, Klára (referee) ; Trunec, Martin (advisor)
Diploma thesis is focused on development of method for preparation individualized bioscaffolds prepared by milling of HA foam prepared by gel casting method and consolidated via epoxy curing reaction. Diploma thesis continues in bachelor thesis Modern processing methods of porous bioceramics. Literature search is filled in the newest knowledge from the field of bioactivity enhancement of scaffolds. Experimental part of diploma thesis described development of system for individualized scaffold manufacturing from HA suspension preparation, preparation of ceramic blocks used as material for machining to final blocks machining. Pressure strength of foam were evaluated, too. Chosen samples were coated with calcium polyphosphate coating for biological response enhancement. Coated samples were given for in-vivo test to partner university in Beijing under the terms of project FP7-NMP-2013-EU-China: "Bioscaffolds"
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Advanced ceramics for tissue engineering
Vojtíšek, Jan ; Koplík, Jan (referee) ; Bartoníčková, Eva (advisor)
This bachelor´s thesis deals issues of ceramics materials suitable for tissue engineering. An artificial substitute for human tissue can be divided to several generations. This include inert, bioactive and bioresobable materials. Resorbable substitutions are prepared from materials, which could substitute host tissue, for example hydroxyapatite. HA can be prepared in different ways (dry and wet way). To better application in medicine, ceramics foams prepared by in situ foaming or replication technique are using. Experimental part of this paper deals preparing of hydroxyapatite powder and process optimization. Samples was characterized by IR and Raman spectrometry, XRD analysis and particle size was studied by SEM. Ceramics foams was prepared by in situ foaming from Al2O3, HA and composites (in ratio 50 – 50, 75 – 25, 90 – 10). Porosity was evaluated by stereomicroscope, density and level of sintering was studied by SEM microscopy.
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Influence of nanoparticles on polymer chains in solution.
Bayer, Adam ; Chamradová, Ivana (referee) ; Jančář, Josef (advisor)
High surface area of used nanoparticles and their comparable size with polymer chains, are the most important characteristics of fillers in the preparation of non-Newtonian suspensions. Such structures at different concentrations have major influence on the rheological behavior of polymer solution in solvent. With increasing volume fraction of nanofiller, there is pseudoplastic or dilatant behavior present in the dissolved elastomers. Diploma thesis studies the influence of the concentration of different elastomers (SBR and SEBS copolymers) and nanofiller (hydrophobic nanosilica) in suspension, of rheological properties.
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Transparent polycrystalline ceramics at visible and infrared wavelenghts
Veselý, Jan ; Maca, Karel (referee) ; Trunec, Martin (advisor)
his thesis deals with preparation of transparent ceramic sheets made out of sub-µm alumina powder. Green bodies are prepared by ultraviolet (UV) curing of UV curable resin containing ceramic powder followed by debinding of organic parts at elevated temperature. High relative density of green bodies is essential for reduction of shrinkage during subsequent sintering process. Therefore high solids loading dispersions containing > 57 vol% ceramic particles are used. To reach transparent behaviour, porosity within the sheets must be reduced completely. Therefore hot isostatic pressing (HIP) is used as a final operation. Finally, light transmission and hardness measurements are presented. Possibilities of making high resolution microstructures using maskless lithography and some suggestions for use of the UV curing technique for production of complex-shaped 3D structures are briefly mentioned.
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Compaction of ceramic nanoparticle suspensions by centrifugal forces
Mišák, Jiří ; Maca, Karel (referee) ; Trunec, Martin (advisor)
In bachelor’s thesis, there was researched compacting of ceramic suspensions prepared from aluminium oxide with particle size of 100 nm by centrifugal forces. The homogeneity of centrifuged bodies was described in dependence of the speed of centrifugation. It was shown, that homogenous plate samples with regular particle packing could be prepared from centrifuged bodies. The structure and sintering behaviour of such bodies were superior to samples prepared by cold isostatic pressing. Similar properties could be reached in samples prepared from suspension with high loading (47,5 vol.%) as well as with lower loading (20 vol.%). The advantage of regular and dense particle packing by centrifugal compaction was demonstrated by manufacturing of transparent ceramic samples.
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Separation of rigid particles from heterogeneous suspension
Prax, Ondřej ; Debreczeni, Ondřej (referee) ; Pochylý, František (advisor)
The bachelor thesis contains a literature search dealing with the separation of solid particles from a heterogenic suspension. The first part is aimed at separation methods. Then, a chapter follows dealing with separation devices, which are used in waste water treatment plants. A more detailed description of the separator used for the separation of sand from waste waters is part of this paper. The described device serving to separate solid particles from a suspension uses the combination of sedimentation and separation methods. To visualize the separator a 3D model in Autodesk Inventor Professional 9 device was used in the presented paper.
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Gelcasting of Advanced Ceramics
Veselý, Jan ; Maca, Karel (referee) ; Trunec, Martin (advisor)
In Bachelor thesis, a literary overview of gelcasting method was worked out and pursuant to this overview, composition of alumina suspension was optimised for fabrication of bulky and complex-shape ceramic part. Four variants of ceramic powder filling in suspensions were prepared. Based on the experiments, a suspension with powder loading of 47,5 vol. % was chosen. The ratio between linear and crosslinking monomers was investigated for this suspension. A suspension with monomer ratio of 4 : 1 (linear : crosslinking) was chosen for preparation of bulky and complex-shape ceramic part. Gelcasting was verified by fabrication of ceramic medal and a knee-joint.
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Sealing Diaphragm Walls
Kaderka, Jan ; Boštík, Jiří (referee) ; Svoboda, Petr (advisor)
The topic of this thesis is history, the purpose to carry out diaphragm wall, types of the emplyoed technologies and specific examples of its application in practise. Part of this thesis will concantrate on the parametres of bonding agents and the grouting mixtures.
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Production and Examination of Foam Ceramic Filters
Ondrášek, Jan ; Sokolář, Radomír (referee) ; Nevřivová, Lenka (advisor)
The aim of this thesis is to describe manufacture of the ceramic foam filters and its materials. Thesis includes description of manufacture of ceramic shard, properties of ceramic suspension and testing carried out not only on materials, but also on fired ceramic filter. Furthermore this thesis includes experimental part which includes evaluation of influence of viscosity on final firmness of the filter and its contraction by desiccation and firing.
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