Page 165 - Materials Chemistry, Second Edition

152 2 Solid-State Chemistry

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Comyns, A. E. Focus on Catalysts 2009, 4,1.
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For more information regarding the mechanism for glass formation, see: Royall, C. P.; Williams, S. R.;
Ohtsuka, T.; Tanaka, H. Nature Mater. 2008, 7, 556.
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Note: it should be noted that glass is not 100% transparent; that is, some incident light is reflected -
even in glass that is free from dopant or other inclusion impurities.
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Note: in addition to scattering processes, a better rationale for the transparency of glass is due to its
electronic band structure, in which the HOMO/LUMO gap is too large to absorb visible light.
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It should be known that other oxides are capable of glass network formation, such as B 2 O 3 , GeO 2 ,
P 2 O 5 ,As 2 O 5 ,As 2 O 3 ,Sb 2 O 3 , and to a limited degree V 2 O 5 , ZrO 2 and Bi 2 O 3 . The oxides of Te, Mo, W,
Bi, Ba, Nd, Ti, Zn, Pb, Al, Th and Be are known as conditional glass formers. These may be included
in varying concentrations, but will not on their own, yield a glass. These, and other oxides that will not
form a glass (including Sc, La, Y, Sn, Ga, In, Mg, Li, Sr, Cd, Rb, Hg, and Cs) are used as network
modifiers, to vary the melt viscosity and afford varying properties to the glass.
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For more information regarding other crystalline forms, see: Douglas, B. E.; Ho, S. -M. Structure and
Chemistry of Crystalline Solids, Springer: New York, 2006.
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Note: this is a useful exploitation of the freezing-point depression colligative property, as taught in
introductory physical chemistry (e.g., adding salt to icy roads in the winter).
79
The Complete Book on Glass and Ceramics Technology, NIIR Board of Consultants and Engineers,
Asia Pacific Business Press, Inc., 2005.
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Some remaining stock of safe, weakly radioactive glass items such as ceramic plates, ore, marbles, etc.
may still be acquired online from http://www.unitednuclear.com/
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For more details on the history, properties, and fabrication of fiber optics, see: Glass, A. M.;
DiGiovanni, D. J.; Strasser, T. A.; Stentz, A. J.; Slusher, R. E.; White, A. E.; Kortan, A. R.; Eggleton,
B. J. Bell Labs Techn. J. 2000, Jan. - March, 168.
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http://en-us.transitions.com/
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For example, see: Armistead, W. H.; Stookey, S. D. Science 1964, 144, 15.
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For example, see: Morse, D. L. Inorg. Chem. 1981, 20, 777, and references therein.
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Richardson, T. J.; Slack, J. L.; Armitage, R. D.; Kostecki, R.; Farangis, B.; Rubin, M. D.; Appl. Phys.
Lett. 2001, 78, 3047.
86
Asphalt is a black, sticky, viscous liquid that is obtained from crude petroleum. It comprises almost
entirely a form of tar called bitumen. The structure of asphalt is actually a colloidal suspension, with
small particulates called asphaltenes dispersed through the petroleum matrix. More environmentally
friendly aqueous-based asphalt emulsions are currently being used for road repair applications.
87
For more details regarding the role of C4AF in the hardening mechanisms of Portland cement, see:
Meller, N.; Hall, C.; Jupe, A. C.; Colston, S. L.; Jacques, S. D. M.; Barnes, P.; Phipps, J. J. Mater.
Chem. 2004, 14, 428, and references therein.
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A nice summary of ceramic processing is found online at: http://www.engr.sjsu.edu/~wrchung/
images/MatE155/sp06/ceramicsprocessing.pdf
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Ratner, B. D.; Hoffman, A. S.; Schoen, F. J.; Lemons, J. E. Biomaterials Science, 2nd ed., Academic
Press: New York, 2004.
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Aninwene, G. E.; Yao, C.; Webster, T. J. Int. J. of Nanomed. 2008, 3, 257.
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Klein, C. Biomaterials. 1990, 11, 509.
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LeGeros, R. Z.; LeGeros, J. P. Adv. in Science and Technol., 49, 203.
Topics for Further Discussion
1. Considering that Si has the zinc blende crystal structure, draw the (111), (110), and (100) planes of Si.
Place these planes in order of highest atomic density, from least to greatest. What impact would the
structures of these planes have on their relative surface reactivities?