Mono-crystalline Nanometer High Cristobalite Glass-ceramics from Nominal Pyroxene Glass

Transparent glass was prepared from nominal alkali pyroxene (Na2MgSi2O6) composition. The results showed that the incorporation of Cr2O3 in alkali pyroxene composition with 0.5 and 1.0 wt% increased the crystallization temperature of high cristobalite. High cristobalite was developed alone in all glass samples heat-treated at 800 degrees C. The microstructure shows nanometer crystals of high cristobalite which spread in glassy matrix. The density, hardness and coefficient of thermal expansion were between 2.49 and 2.53 g/cm(3), 505 and 611 kg/mm(2) and between 9.38 and 13.32 x 10(- 6) degrees C- 1 (30-300 C ), respectively for the three glass-ceramic compositions. All the samples have moderate to excellent antimicrobial activity on both gram positive bacteria (Staphyllococus aureus ) and pathogenic fungal yeast (Candida albicans), which show broad spectrum antimicrobial activity toward bacteria and fungi, while the sample NMCr1 has an excellent antifungal activity only toward the pathogenic fungal yeast (Candida albicans), which was described as a promising antifungal agent.

Automated summary

Transparent glass prepared from nominal alkali pyroxene composition with the incorporation of Cr2O3 exhibited an increased crystallization temperature of high cristobalite. The glass-ceramic samples showed nanometer crystals of high cristobalite with moderate to excellent antimicrobial activity against both gram positive bacteria and pathogenic fungal yeast. Sample NMCr1 demonstrated excellent antifungal activity specifically against Candida albicans, indicating potential as an antifungal agent.