(W7860)Monte Carlo Simulations of the Dissolution of Borosilicate and Aluminoborosilicate

Journal Article · Sat Jan 01 04:00:00 EST 2011 · Geochimica et Cosmochimica Acta

DOI:https://doi.org/10.1016/j.gca.2011.06.036· OSTI ID:1021993

Kerisit, Sebastien ^[1]; Pierce, Eric M ^[2]

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1. Pacific Northwest National Laboratory (PNNL)
2. ORNL

The aim of this study was to provide atomic-level insights into the dissolution behavior of borosilicate and aluminoborosilicate glasses in dilute aqueous solutions. In the first part of this work, the effects of different structural features, such as the presence of non-bridging oxygens (NBO) or the formation of boroxol rings, on glass dissolution were evaluated separately and led to the following conclusions. (1) The dependence of the dissolution rate on the amount of NBO was found to be linear at all Si/B ratios and the accelerating effect of NBO was shown to increase with increasing Si/B ratio. (2) The formation of boroxol rings and of clusters of boroxol rings resulted in an increase of the dissolution rate at all Si/B ratios and, again, the extent of the rate increase was strongly dependent on the Si/B ratio. (3) For aluminosilicate glasses, the implementation of the aluminum avoidance rule was found to increase the rate of dissolution relative to that obtained for a random distribution. In the second part of this work, the dissolution of the NeB glasses studied by Pierce et al. [Pierce E. M., Reed L. R., Shaw W. J., McGrail B. P., Icenhower J. P., Windisch C. F., Cordova E. A. and Broady J. (2010) Experimental determination of the effect of the ratio of B/Al on glass dissolution along the nepheline (NaAlSiO4) - Malinkoite (NaBSiO4) join. Geochim. Cosmochim. Acta 74, 2634-2654] was modeled in dilute aqueous solutions. Pierce et al. concluded from their study that either the rupture of the Al-O bonds or that of the Si O bonds was the rate-limiting step controlling the dissolution of the NeB glasses. The simulations refined this conclusion and showed that, at low B/Al ratios, the rupture of both Al O Si and Si O Si linkages contributed to the dissolution rate whereas, at high B/Al ratios, the dissolution rate was independent of the rupture of Al-O-Si linkages and was controlled by S1 sites (silicon sites at the glass-water interface with one connection to nearest-neighbor sites) and dissolution via detachment of clusters.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: ORNL work for others
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1021993
• Journal Information: Geochimica et Cosmochimica Acta, Journal Name: Geochimica et Cosmochimica Acta Journal Issue: 18 Vol. 75; ISSN GCACAK; ISSN 0016-7037
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ALUMINIUM
AQUEOUS SOLUTIONS
BOROSILICATE GLASS
DISSOLUTION
DISTRIBUTION
GLASS
IMPLEMENTATION
INTERFACES
MONTE CARLO METHOD
RUPTURES
SILICON
SIMULATION
WATER
dissolution
glass
mineral
monte carlo
weathering