Structural details of aqueous attack on a phosphate glass by 1H/31P cross-polarization NMR
Article Abstract:
The incorporation of water into a simple phosphate glass network has been studied with one- and two-dimensional heteronuclear correlation solid-state nuclear magnetic resonance spectroscopy. The dynamics of aqueous attack is important for understanding the relationships between glass properties and composition. Results indicate water-modified glass contains five distinct phosphate units. These are Q1 and Q2 phosphate sites with only sodium next-nearest neighbors, a Q0(1H) unit in which the hydroxyl group is involved in strong hydrogen bonding. A Q1(1H) unit involved in weak hydrogen bonding and a Q2 phosphate site next to a Q1(1H) site.
Publication Name: Journal of Physical Chemistry B
Subject: Chemicals, plastics and rubber industries
ISSN: 1520-6106
Year: 1998
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Enumeration of isobaric inherent structures for the fragile glass former o-terphenyl
Article Abstract:
A study was conducted to analyze the enumeration of isobaric inherent structures for the fragile glass former o-terphenyl. A dimensionless partition function was used to determine equilibrium statistical mechanics under isobaric conditions. Experimental results indicated that supercooling o-terphenyl from its melting point to its glass transition reduces inherent structure enthalpy by 66% of the amount that would be needed to realize the most stable amorphous inherent structure.
Publication Name: Journal of Physical Chemistry B
Subject: Chemicals, plastics and rubber industries
ISSN: 1520-6106
Year: 1998
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Distinguishing vibrational and structural equilibration contributions to thermal expansion
Article Abstract:
A study was conducted to investigate the divergent behavior of isobaric thermal expansion in the liquid-vapor critical region. The experiment raises the intriguing, open issue of how the critical divergence of the isobaric thermal expansion property, alpha, should be apportioned between vibrational and structural equilibration contributions. More generally, the relationship between negative alpha and negative volume of melting remains to be investigated.
Publication Name: Journal of Physical Chemistry B
Subject: Chemicals, plastics and rubber industries
ISSN: 1520-6106
Year: 1999
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