OPTI 201R 10 L10

OPTI 201R 10 L10 - 10-1 4.4 Glass !"Glass is: !...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
10-1 OPTI 201R Fall 2010 4.4 Glass ! Glass is: ! "ancient" - at least 5000 years old. - developed by the Phoenicians about 3000 B.C. ! silicon-based (SiO 2 , silicon dioxide, "silica"…. .sand!!!). ! an amorphous solid ("vitreous") - no "long-range" order to the position of the atoms. - achieved using a high rate of cooling. ! not a super-cooled liquid. - old church windows do not "flow" downwards, making them thicker at the bottom. " Is Glass Liquid or Solid? " (optional reading) ! transparent through the visible spectrum. - due to the absence of homogeneity. - transmission > 95% from 400-700nm. - typically opaque in the ultra-violet and infrared spectrum. - Fused quartz (pure SiO 2 ) transmits in the UV. ! chemically and biologically inert.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
10-2 OPTI 201R Fall 2010 4.4.1 Chemical Composition ! " Quartz " - Crystalline form of pure SiO 2 : - SiO 4 silicon-oxygen tetrahedral structure - each oxygen atom is shared between 2 tetrahedra - resulting structure is SiO 2 - melting point # $%%%&’ - occurs in nature as "quartz crystals" ! "Fused quartz" - Non-crystalline form of SiO 2 - manufactured by melting naturally-occurring quartz crystals of high purity at # $$%%&’( - electrically-heated or gas-oxygen furnace. ! "Fused silica" - manufactured using high-purity silica sand - electric furnace. - trapped air bubbles make it translucent or opaque.
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 10

OPTI 201R 10 L10 - 10-1 4.4 Glass !"Glass is: !...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online