Příprava keramických vláken elektrostatickým zvlákňováním
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Vysoké učení technické v Brně. Fakulta strojního inženýrství
Abstract
Diplomová práca je zameraná na prípravu keramických vlákien elektrostatickým zvlákňovaním. Teoretická časť diplomovej práce zhrňuje doposiaľ známe informácie v oblasti keramických vlákien, ich vlastností, aplikácií a výroby. Teoretická časť tiež popisuje proces elektrostatického zvlákňovania ako jednu z najpoužívanejších metód výroby nanovlákien a parametre, ktoré tento proces ovplyvňujú. Experimentálna časť je zameraná na prípravu keramických vlákien na báze oxidu titaničitého, čistého nedopovaného oxidu zirkoničitého a ytriom dopovaného oxidu zirkoničitého metódou elektrostatického zvlákňovania a na charakterizáciu takto pripravených vlákien. Zvlákňované boli keramické prekurzory zložené z propoxidu a polyvinylpyrolidonu. Experimentálna časť diplomovej práce tiež popisuje vplyv zloženia prekurzoru, procesných podmienok a teploty kalcinácie na morfológiu a fázové zloženie vlákien. Prekurzory boli charakterizované pomocou merania viskozity. K popisu vlákien bola použitá termogravimetrická analýza (TGA), röntgenová analýza (RTG) a elektrónová rastrovacia mikroskopia (SEM). Elektrostatickým zvlákňovaním prekurzorov na báze propoxidu titaničitého a následnou kalcináciou pri teplote 500 až 1300 °C boli pripravené TiO2 vlákna s hrúbkou 100 až 2500 nm, pričom sa fázové zloženie s kalcinačnou teplotou menilo od anatasovej fázy, cez zmes s rutilom až po čistý rutil. Elektrostatickým zvlákňovaním prekurzorov na báze propoxidu zirkoničitého a následnou kalcináciou pri teplotách 550 až 1100 °C boli pripravené ZrO2 vlákna dopované 0 – 8 mol.% Y2O3 s hrúbkou v rozmedzí 50 až 1000 nm. Analýza vlákien na báze nedopovaného ZrO2 kalcinovaných na teplotu 550 °C ukázala prevažujúce zloženie monoklinickej fáze. Analýza 3 resp. 8 mol.% Y2O3 dopovaného ZrO2 kalcinovaných na teplotu 900 °C ukázala zloženie prevažujúcej tetragonálnej fáze resp. zloženie čisto kubickej fáze. V závislosti na zvyšujúcej sa teplote kalcinácie dochádzalo ku zmene morfológie vlákien od poréznej nanoštruktúry po retiazkovitú neporéznu štruktúru, ktorá bola tvorená mikrometrovými zrnami TiO2, resp. ZrO2. Vlákna ZrO2 po kalcinácii na teplotu 700 °C zostávali stále pružné, rovnako ako tie zvláknené (as spun), pričom so zvyšujúcou sa teplotou kalcinácie sa zvyšovala aj ich krehkosť.
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.
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.
Description
Citation
NEMČOVSKÝ, J. Příprava keramických vláken elektrostatickým zvlákňováním [online]. Brno: Vysoké učení technické v Brně. Fakulta strojního inženýrství. 2017.
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Document version
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Language of document
cs
Study field
Materiálové inženýrství
Comittee
prof. Ing. Ivo Dlouhý, CSc. (předseda)
prof. Ing. Jiří Švejcar, CSc. (místopředseda)
prof. Ing. Rudolf Foret, CSc. (člen)
prof. RNDr. Karel Maca, Dr. (člen)
prof. Mgr. Tomáš Kruml, CSc. (člen)
doc. Ing. Jana Sobotová, Ph.D. (člen)
Date of acceptance
2017-06-13
Defence
Result of defence
práce byla úspěšně obhájena
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Standardní licenční smlouva - přístup k plnému textu bez omezení