Novel Oxyfluoride Biophotonic Glass-Ceramics
Szczodra, Agata (2019)
2019
Materiaalitekniikan DI-ohjelma - Degree Programme in Materials Science and Engineering
Tekniikan ja luonnontieteiden tiedekunta - Faculty of Engineering and Natural Sciences
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Hyväksymispäivämäärä
2019-09-30
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tuni-201909243486
https://urn.fi/URN:NBN:fi:tuni-201909243486
Tiivistelmä
Phosphate glasses are very interesting due to several properties, such as good thermal and mechanical stabilities, high transparency, low refractive index, low melting temperature and high gain density (Wa,03; Pr,08; Hr,13; Do,15). Most importantly, they exhibit higher solubility for RE ions, without clustering effect, compared to silica based glasses (Sh,05). Phosphate glasses are used for optical fibers and laser gain media applications (Mi,91; Su,15) and also for medical applications (Ne,08).
Second paragraph Oxyfluoride glasses combine advantages of fluoride and oxide glasses. Fluoride glasses have lower phonon energy but oxide glasses usually have much better chemical durability, thermal stability and mechanical strength than the fluoride glasses (Cu,16). As reported by (Cu,16) novel oxyfluoride phosphate glasses combining all these advantages are promising materials for bioactive and optical applications.
These glasses can be made with addition of rare-earth ions which are used for a wide range of applications such as telecommunications, light detection and ranging (LIDAR), solar panels, spectroscopy, and bio-imaging (De,98). In this thesis, Er3+ ions which show characteristic 1530 nm wavelength emission, have been used. Moreover, dopants like TiO2, MgO and ZnO which affect thermal, structural and luminescence properties are often added to phosphate based glasses (Po,06; Cu,16).
To obtain better thermal and mechanical properties, glass-ceramic can be produced from glasses. This is done by using heat treatment process which allows one to achieve controlled crystallization of glass.
PeL properties of glass and glass-ceramic can be utilized in biophotonic PeL phosphate glasses. Such glasses can be used as bone implant, the mineralization of which can be tracked in-vivo. As reported by (Zh,16), PeL glass-ceramics can be produced using direct doping method in which PeL microparticles are added to the glass melt.
Finally, the feasibility of patterning microstructured 2D gratings at the surface of phosphate glass is investigated. The ability to carry out glass micropatterning in a cost- and time-effective fashion is crucial for producing devices and structures based on these materials for the mentioned applications. A potential use of the fabricated 2D gratings for monitoring phosphate glass degradation in wet environments through optical diffraction measurements is also introduced.
In the first and second chapter, the basic knowledge about glasses and materials and methods are described, respectively. In the results and discussion part, the impact of the glass composition on the glass is first investigated. Then, the effect of the heat treatment on produced glass-ceramic is described. Finally, the work on PeL oxyfluoride biophotonic glass-ceramics and patterning is presented. The impact of melting parameters and PeL microparticles concentration on luminescence properties is discussed. Conclusions and next steps are summarized in the last chapter.
Second paragraph Oxyfluoride glasses combine advantages of fluoride and oxide glasses. Fluoride glasses have lower phonon energy but oxide glasses usually have much better chemical durability, thermal stability and mechanical strength than the fluoride glasses (Cu,16). As reported by (Cu,16) novel oxyfluoride phosphate glasses combining all these advantages are promising materials for bioactive and optical applications.
These glasses can be made with addition of rare-earth ions which are used for a wide range of applications such as telecommunications, light detection and ranging (LIDAR), solar panels, spectroscopy, and bio-imaging (De,98). In this thesis, Er3+ ions which show characteristic 1530 nm wavelength emission, have been used. Moreover, dopants like TiO2, MgO and ZnO which affect thermal, structural and luminescence properties are often added to phosphate based glasses (Po,06; Cu,16).
To obtain better thermal and mechanical properties, glass-ceramic can be produced from glasses. This is done by using heat treatment process which allows one to achieve controlled crystallization of glass.
PeL properties of glass and glass-ceramic can be utilized in biophotonic PeL phosphate glasses. Such glasses can be used as bone implant, the mineralization of which can be tracked in-vivo. As reported by (Zh,16), PeL glass-ceramics can be produced using direct doping method in which PeL microparticles are added to the glass melt.
Finally, the feasibility of patterning microstructured 2D gratings at the surface of phosphate glass is investigated. The ability to carry out glass micropatterning in a cost- and time-effective fashion is crucial for producing devices and structures based on these materials for the mentioned applications. A potential use of the fabricated 2D gratings for monitoring phosphate glass degradation in wet environments through optical diffraction measurements is also introduced.
In the first and second chapter, the basic knowledge about glasses and materials and methods are described, respectively. In the results and discussion part, the impact of the glass composition on the glass is first investigated. Then, the effect of the heat treatment on produced glass-ceramic is described. Finally, the work on PeL oxyfluoride biophotonic glass-ceramics and patterning is presented. The impact of melting parameters and PeL microparticles concentration on luminescence properties is discussed. Conclusions and next steps are summarized in the last chapter.