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Electrospinning of ceramic fibers
Nemčovský, Jakub ; Kaštyl, Jaroslav (referee) ; Částková, Klára (advisor)
This diploma thesis focuses on the fabrication of ceramic fibres by electrospinning. The theoretical part of the thesis summarizes the currently available information regarding ceramic fibres, their properties, applications and fabrication. The theoretical part also describes the process of electrospinning as one of the most frequently used methods of nanofibre fabrication, as well as the parametres influencing this process. The experimental part is aimed at the fabrication of ceramic fibres based on titania, pure non-doped zirconia and yttria-doped zirconia by electrospinning and at the characterization of thus fabricated fibres. Ceramic precursors based on propoxide and polyvinylpyrrolidone were subjected to electrospinning. The experimental part of this diploma thesis also describes the influence of precursor composition, process conditions and calcination temperature on the morphology and phase composition of the fibres. Precursors were characterized by viscosity measurements. Thermogravimetric analysis (TGA), Röntgen analysis (RTG) and scanning electron microscopy (SEM) were used to describe the fibres. By performing electrospinning of precursors based on titanium propoxide and subsequent calcination at 500-1300 °C, TiO2 fibres with thickness of 100-2500 nm were fabricated. The phase composition changed with calcination temperature from 500 °C from anatase phase through rutile blend to pure rutile at 900 °C. By performing electrospinning of precursors based on zirconium propoxide and subsequent calcination at 550-1100 °C, 0 – 8 mol% Y2O3 doped ZrO2 fibres with thickness of 50-1000 nm were fabricated. An analysis of fibres based on non-doped ZrO2, calcined at 550 °C showed a composition of predominantly monoclinic phase. An analysis of 3 or 8 mol% Y2O3 doped ZrO2 fibres calcined at 900 °C showed a composition of predominantly tetragonal phase or purely cubic phase, respectively. With the increasing calcination temperature, the morphology of the fibres changed from porous nanostructure to chain-like non-porous structure consisting of micrometer grains of TiO2 or ZrO2. The ZrO2 fibres calcined at 700 °C remained flexible as well as the spun ones, while their fragility increased with the increase in calcination temperature.
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Influence of the polymer mixture composition on the properties of polysaccharide fibrous biomaterials
Kavčiaková, Zuzana ; Pavliňáková, Veronika (referee) ; Vojtová, Lucy (advisor)
Navrhovaná diplomová práca sa zaoberá prípravou a hodnotením vlastností vlákien na báze polysacharidu Gum Karaya a jeho zmesí s poly(vinylalkoholom), poly(vinylpyrolidínom) a poly(etylénoxidom). Diplomová práca je rozdelená na teoretickú, experimentálnu a diskusnú časť. V teoretickej časti je opísaná príprava a charakterizácia vlákien rôznej veľkosti. Experimenty zahŕňajú prípravu vlákien metódou elektrospinningu. Získané vlákna boli analyzované pomocou Fourierovej transformovanej infračervenej (FT-IR) spektroskopie, rastrovacej elektrónovej mikroskopie (SEM), dynamickej mechanickej analýzy (DMA) a gravimetrickej metódy na vyhodnotenie pomeru napúčania vlákien. Elektro-zvláknené vlákna získané z vodného roztoku organických kyselín sa osvedčili ako vhodný materiál s dostatočne dobrým priemerom vlákien a pevnosťou v ťahu.
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Influence of the polymer mixture composition on the properties of polysaccharide fibrous biomaterials
Kavčiaková, Zuzana ; Pavliňáková, Veronika (referee) ; Vojtová, Lucy (advisor)
Navrhovaná diplomová práca sa zaoberá prípravou a hodnotením vlastností vlákien na báze polysacharidu Gum Karaya a jeho zmesí s poly(vinylalkoholom), poly(vinylpyrolidínom) a poly(etylénoxidom). Diplomová práca je rozdelená na teoretickú, experimentálnu a diskusnú časť. V teoretickej časti je opísaná príprava a charakterizácia vlákien rôznej veľkosti. Experimenty zahŕňajú prípravu vlákien metódou elektrospinningu. Získané vlákna boli analyzované pomocou Fourierovej transformovanej infračervenej (FT-IR) spektroskopie, rastrovacej elektrónovej mikroskopie (SEM), dynamickej mechanickej analýzy (DMA) a gravimetrickej metódy na vyhodnotenie pomeru napúčania vlákien. Elektro-zvláknené vlákna získané z vodného roztoku organických kyselín sa osvedčili ako vhodný materiál s dostatočne dobrým priemerom vlákien a pevnosťou v ťahu.
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Nanofibrous scaffolds in controlled delivery of autologous growth factors
Buzgo, Matej ; Amler, Evžen (advisor) ; Gášková, Dana (referee)
Platelet preparations are a source of various autologous growth factors and have numerous applications in tissues engineering. The aim of this work was to development electrospun nanofiber scaffolds with platelet preparations. Scaffolds based on the adhesion of platelets on nanofiber meshes were developed. The scaffolds were able to enhance chondrocyte proliferation in vitro. The main disadvantage of this system is the burst release of growth factors immediately after adhesion. To overcome this, we developed coaxially electrospun scaffolds with incorporated alpha granules. Alpha granules are novel platelet preparations with high amounts of growth factors. This system was able to stimulate chondrocyte proliferation and maintain TGF- 1 concentrations for 7 days. Additionally, a novel drug delivery system with coaxially incorporated liposomes was developed. Liposomes incorporated into nanofibers remain intact and can be used for the delivery of various molecules. The ability to maintain HRP activity was compared to systems based on coaxial electrospinning with liposomes, coaxial electrospinning without liposomes and blend electrospinning. When compared to other systems, coaxial electrospinning with liposomes preserves enzyme activity twice as long. These results clearly indicate the potential of...
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Electrospinning of ceramic fibers
Nemčovský, Jakub ; Kaštyl, Jaroslav (referee) ; Částková, Klára (advisor)
This diploma thesis focuses on the fabrication of ceramic fibres by electrospinning. The theoretical part of the thesis summarizes the currently available information regarding ceramic fibres, their properties, applications and fabrication. The theoretical part also describes the process of electrospinning as one of the most frequently used methods of nanofibre fabrication, as well as the parametres influencing this process. The experimental part is aimed at the fabrication of ceramic fibres based on titania, pure non-doped zirconia and yttria-doped zirconia by electrospinning and at the characterization of thus fabricated fibres. Ceramic precursors based on propoxide and polyvinylpyrrolidone were subjected to electrospinning. The experimental part of this diploma thesis also describes the influence of precursor composition, process conditions and calcination temperature on the morphology and phase composition of the fibres. Precursors were characterized by viscosity measurements. Thermogravimetric analysis (TGA), Röntgen analysis (RTG) and scanning electron microscopy (SEM) were used to describe the fibres. By performing electrospinning of precursors based on titanium propoxide and subsequent calcination at 500-1300 °C, TiO2 fibres with thickness of 100-2500 nm were fabricated. The phase composition changed with calcination temperature from 500 °C from anatase phase through rutile blend to pure rutile at 900 °C. By performing electrospinning of precursors based on zirconium propoxide and subsequent calcination at 550-1100 °C, 0 – 8 mol% Y2O3 doped ZrO2 fibres with thickness of 50-1000 nm were fabricated. An analysis of fibres based on non-doped ZrO2, calcined at 550 °C showed a composition of predominantly monoclinic phase. An analysis of 3 or 8 mol% Y2O3 doped ZrO2 fibres calcined at 900 °C showed a composition of predominantly tetragonal phase or purely cubic phase, respectively. With the increasing calcination temperature, the morphology of the fibres changed from porous nanostructure to chain-like non-porous structure consisting of micrometer grains of TiO2 or ZrO2. The ZrO2 fibres calcined at 700 °C remained flexible as well as the spun ones, while their fragility increased with the increase in calcination temperature.
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Nanofibrous scaffolds in controlled delivery of autologous growth factors
Buzgo, Matej ; Amler, Evžen (advisor) ; Gášková, Dana (referee)
Platelet preparations are a source of various autologous growth factors and have numerous applications in tissues engineering. The aim of this work was to development electrospun nanofiber scaffolds with platelet preparations. Scaffolds based on the adhesion of platelets on nanofiber meshes were developed. The scaffolds were able to enhance chondrocyte proliferation in vitro. The main disadvantage of this system is the burst release of growth factors immediately after adhesion. To overcome this, we developed coaxially electrospun scaffolds with incorporated alpha granules. Alpha granules are novel platelet preparations with high amounts of growth factors. This system was able to stimulate chondrocyte proliferation and maintain TGF- 1 concentrations for 7 days. Additionally, a novel drug delivery system with coaxially incorporated liposomes was developed. Liposomes incorporated into nanofibers remain intact and can be used for the delivery of various molecules. The ability to maintain HRP activity was compared to systems based on coaxial electrospinning with liposomes, coaxial electrospinning without liposomes and blend electrospinning. When compared to other systems, coaxial electrospinning with liposomes preserves enzyme activity twice as long. These results clearly indicate the potential of...
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