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Silica-based glass ceramics are widely used in biomedical applications due to their exceptional biocompatibility and tailorable properties. However, their application is often limited by low mechanical strength, which can be improved by optimizing the crystalline phase that determines their final properties. Silicon nitride (Si₃N₄) and Zirconia (ZrO₂) are particularly appealing ceramics due to their favorable combination of mechanical strength and biological compatibility. In this thesis, the development of two types of glass ceramics, Si₃N₄-SiO₂ and ZrO₂-SiO₂ glass ceramics is explored to address these challenges by controlling their microstructure and engineering the nanointerfaces between ceramic/ceramic grains and ceramic grain/glass matrix.

In Si₃N₄-SiO₂ glass ceramics, raw powders containing three different Si₃N₄ contents were prepared. The results showed that the β-Si₃N₄ crystalline phase is well distributed within the SiO₂ matrix. The mechanical properties of the glass ceramics improved with increasing Si₃N₄ content and increasing sintering temperature, reaching a maximum flexural strength of 452±33 MPa and fracture toughness of 6.4±0.5 MPa∙m^1/2 at 70 wt% Si₃N₄ composition. The highest antibacterial rate against S. epidermidis was observed in the 50SiN samples, at 79%. 

In the ZrO₂-SiO₂ glass ceramics, the raw powders with varying types (K⁺, Mg²⁺, Al³⁺, Ce⁴⁺, and Ta⁵⁺) and amounts of dopants were prepared by a modified sol-gel method. TEM results showed the ZrO₂ crystals were embedded within the amorphous SiO₂ matrix, with Mg²⁺, Al³⁺, and Ce⁴⁺ ions primarily segregating at the grain boundaries of ZrO₂ crystals while K⁺ and Ta⁵⁺ ions mainly dissolved within the grains. The Mg-doped samples showed the highest toughness at 12.39±1.34 MPa∙m^1/2, attributed to the enhanced interfacial strength between the dopants and ZrO₂ crystals. FEM simulation shows that enhanced interfacial bonding lead to more diffused cracking and dissipating energy compared to the conventional interfacial weakening theory. The antibacterial performance of the ZrO₂-SiO₂  was improved by nitrogen ion implantation of the surface. The antibacterial rate against S.aureus reached 49 ± 24% for samples implanted at fluences of 1×10¹⁷ ions/cm^².

In conclusion, different SiO₂ matrix glass ceramics were developed with enhancing mechanical strength and antibacterial properties. The results indicate that these materials hold significant potential for biomedical applications.