Structure of Phosphate Glasses

One-dimensional - P NMR is only able to probe the the local structure of phosphate glasses. To gain information about the manner in which the different Q" units or domains in phosphate glasses are connected, two-dimensional MAS exchange experiments have been used in which radio-frequency dipolar recoupling (RFDR) techniques allow the reintroduction of the through-space dipolar-dipolar interaction even... 

A number of studies of radiation effects on phosphate glasses have been conducted because of the variety of technological applications for phosphate glasses. There are no studies of phosphate glasses that have been doped with actinides. Based on present studies, which mainly emphasize the effect of ionizing radiation on the structure of phosphate glass, one must anticipate important effects associated with ionization caused by the alpha-particle. 

S.W. Martin, Review of the structures of phosphate glasses. Eur. J. Solid State Inoig. Chem. 28, 163-205 (1991)... 

Kirkpatrick, R.. and Brow, R.K. (1995) Nuclear magnetic resonance investigation of the structures of phosphate and phosphate-containing glasses a review. Solid State Nucl. Magn. Reson., 5, 9-21. 

Meadoweroft T. R. and Richardson F. D. (1965). Structural and thermodynamic aspects of phosphate glasses. Trans. Faraday Soc., 61 54-70. 

Glasses and crystals of sodium vanadate-phosphates with various P/V ratios have been prepared and some information on the structures of these glasses and crystals has been obtained from paper chromatographic analyses of their aqueous solutions. 

Gowda KA (1982) Heavy ion bombardment of zircon, monazite and other crystal structures. PhD dissertation, Marquette University, Milwaukee, Wisconsin Grambow B, Lutze W (1979) Chemical stability of phosphate glass under hydrothermal conditions. In Scientific Basis for Nuclear Waste Management, Vol. 2. Northrap, CJM, Jr (ed) Plenum Press, New York, p 109-116... 

M-SiAlON systems contain a combination of M atoms. Glass formation is found to be easier, more the types of atoms present in the nitrided glasses. Several simple silicates and phosphates which are nitrided have provided much insight into the structure of oxynitride glasses. 

Eirst systematic study of phosphate bonding and phosphate cements Kirsanov reaction discovered Identification of UDP glucose Formulated rules for base composition of DNA Advanced theories of phosphate glass structure First NMR spectra of P compounds published Showed (with P) that viruses work by injecting their DNA or RNA into cells under attack... 

Present structural knowledge of phosphate glasses largely confirms theories put forward by Van Wazer over 50 years ago [7,8]. 

S. Wegner, L. van Wiillen, G. Tricot, The structure of phosphate andborosilicate glasses and their structural evolution at high temperatures as studied with solid state NMR spectroscopy phase separation, crystallisation and dynamic species exchange, Sohd State Sci. 12 (2010) 428-439. 

Since phosphate glass-ceramics exhibit some properties that are more favorable and others that are less favorable than those of silicate glass-ceramics, their special characteristics should be addressed at the beginning of this section. Most of these features are attributed to the different nucleation and crystallization conditions of phosphate glass-ceramics compared with those of silicate glass-ceramics. The glass structure provides the basis for these characteristics. Therefore, the structures of the two glass-ceramics fiunilies must be addressed. 

Figure 2-45 Short-range structure of phosphate (a) (Kirkpatrick and Brow, 1995 Brow et ai., 1995) and siiicate glasses (b).

Kirkpatrick R.J. and Brow R.K., "Nuclear Magnetic Resonance Investigation of the Structures of Phosphate-Containing Glass A Review," Solid State Magn. Reson., 5, 9—21 (1995). 

The chemical stability of phosphate glasses can be improved through the incorporation of nitrogen into the structure. In nitrided amorphous Li3P04 thin films (LiPON), the exceptional stability and enhanced Li conductivity make them attractive for microbattery applications. Reported here are Li, P, and solid-state NMR studies of LiPON thin films fabricated by an ion beam-assisted deposition process. ... 

U. Hoppe, G. Walter, R. Kranold, D. Stachel, Structural spedflcs of phosphate glasses probed by diffraction methods a review. J. Non-Cryst. Solids 263-264, 29-47 (2000)... 

Fig. 10.2 Structure of 45S5 glass. Silicate and phosphate tetrahedra are represented as baU-and-stick, and modifier Na and Ca cations as spheres. The longest silicate chain identified in a model of 45,000 atoms is highlighted in the right panel. Note that most chain fragments in the 45S5 structure are typically much shorter...

The movement of fluoride through the atmosphere and into a food chain illustrates an air-water interaction at the local scale (<100 km) (3). Industrial sources of fluoride include phosphate fertilizer, aluminum, and glass manufacturing plants. Domestic livestock in the vicinity of substantial fluoride sources are exposed to fluoride by ingestion of forage crops. Fluoride released into the air by industry is deposited and accumulated in vegetation. Its concentration is sufficient to cause damage to the teeth and bone structure of the animals that consume the crops. 

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