Presentation on theme: "Nano Quartz Cafer T. Yavuz 10/9/2006. 2 Quartz in nature SiO 2, Silicon dioxide (70%) Macrocrystalline varieties –Amethyst is the purple gemstone variety.Amethyst."— Presentation transcript:
2 Quartz in nature SiO 2, Silicon dioxide (70%) Macrocrystalline varieties –Amethyst is the purple gemstone variety.Amethyst –Citrine is a yellow to orange gemstone variety that is rare in nature but is often created by heating Amethyst.Citrine –Milky Quartz is the cloudy white variety.Milky Quartz –Rock crystal is the clear variety that is also used as a gemstone.Rock crystal –Rose quartz is a pink to reddish pink variety.Rose quartz –Smoky quartz is the brown to gray variety.Smoky quartz
3 Uses of quartz For quality glass Electrical components, fiber optics Optical lenses Ornamental stone and as gemstones Thermal Insulators, infrared ceramic materials Abrasives Crystal oscillators Healing crystals (!) Building stones
4 Structure One of 8 other SiO 2 structures but the most stable one. Isostructural with AlPO 4 (berlinite): helix chains of silicon tetrahedrons
5 Sources for Quartz Mining Industrial, synthetic production –Charles Sawyer’s cultured quartz process Chemical synthesis*
7 Methods for nano quartz Grinding, ball-milling Bottom-up synthesis from silicas –[CHALLENGE]: the amorphous state of silica is nearly equal in energy to that of α-quartz –[CHALLENGE]: extremely rapid growth rate in conditions required for its nucleation (80 nm/sec at 263 °C in 0.5 M NaOH)
15 Conclusions There are only 6 published synthesis of nano-quartz all of them starts from silica Quartz is challenging to synthesize. Size control lacks, further purification is needed New methods, especially non-aqueous, need to be explored
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