Hostname: page-component-78c5997874-4rdpn Total loading time: 0 Render date: 2024-11-02T23:49:44.575Z Has data issue: false hasContentIssue false
  • English
  • Français

Results of Vertical Scanning Interferometry (VSI) of Dissolved Borosilicate Glass: Evidence for Variable Surface Features and Global Surface Retreat

Published online by Cambridge University Press:  11 February 2011

Icenhower J.P. ,
Lüttge A. ,
McGrail B.P. ,
Beig M.S. ,
Arvidson R.S. ,
Rodriguez E.A. ,
Steele J.L.  and
Baum S.R.
Icenhower J.P.
Affiliation:
Pacific Northwest National Laboratory, PO Box 999, Richland, WA 99352, U.S.A.
Lüttge A.
Affiliation:
Rice University, PO Box 1892, Houston, TX 77251–1892, U.S.A.
McGrail B.P.
Affiliation:
Pacific Northwest National Laboratory, PO Box 999, Richland, WA 99352, U.S.A.
Beig M.S.
Affiliation:
Rice University, PO Box 1892, Houston, TX 77251–1892, U.S.A.
Arvidson R.S.
Affiliation:
Rice University, PO Box 1892, Houston, TX 77251–1892, U.S.A.
Rodriguez E.A.
Affiliation:
Pacific Northwest National Laboratory, PO Box 999, Richland, WA 99352, U.S.A.
Steele J.L.
Affiliation:
Pacific Northwest National Laboratory, PO Box 999, Richland, WA 99352, U.S.A.
Baum S.R.
Affiliation:
Pacific Northwest National Laboratory, PO Box 999, Richland, WA 99352, U.S.A.
Get access

Abstract

Two disparate reaction mechanisms have been invoked to explain the reactivity of glass in contact with aqueous solution. One model is based on arguments from Transition State Theory (TST), which postulates that glass dissolution rates are surface reaction controlled. Alternatively, the second model argues that release of elements from glass to solution is governed by diffusion through an altered layer that forms on the surface of glass. Vertical Scanning Interferometry (VSI) is a new technique that allows one to observe surface features of specimens exposed to solution and may, potentially, be used to distinguish between competing models. We performed a series of dissolution experiments with a suite of glass compositions from chemically simple (sodium borosilicate) to complex (sixteen component borosilicate). Dissolution rates were determined using single-pass flow-through (SPFT) apparatus at 90°C and pH = 9 and over a solution saturation interval. Upon termination of the experiments, glass coupons were examined by VSI techniques. Effluent chemistry and VSI measurements indicate a nearly constant rate of 2.2 to 3.4 g m-2 d-1 over the solution interval; rates calculated from both methods are identical within experimental uncertainty. We argue that this glass is phase separated, and propose a model for dissolution based on the relative rates of dissolution of the two glass compositions. The data are consistent with a modified version of TST and indicate the potency of VSI methods to elucidate glass reaction mechanisms.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 757: Symposium II – Scientific Basis for Nuclear Waste Management XXVI , 2002 , II5.1
Copyright
Copyright © Materials Research Society 2003

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Douglas, R.W. and El Shamy, T.M., J. Am. Ceram. Soc. 50, 1 (1967).Google Scholar
2. Eyring, H., Chem. Rev. 17(1), 65 (1935).Google Scholar
3. Lasaga, A.C., in Chemical Weathering Rates of Silicate Minerals, edited by White, A.F. and Brantley, S.L. (Reviews in Mineralogy 31, Miner. Soc. Am., Washington, D.C., 1995) pp. 23–86.Google Scholar
4. Aagaard, P. and Helgeson, Am. J. Sci. 282, 237–285 (1982).Google Scholar
5. Jégou, C., Gin, S. and Larché, F., J. Nuc. Mat. 280, 216–229 (2000).Google Scholar
6. Grambow, B.E., in Scientific Basis for Nuclear Waste Management VII, edited by Jantzen, C.M., Stone, J.A. and Ewing, R.C. (Mat. Res. Soc. Proc. 44, PA, 1985) pp. 15–27.Google Scholar
7. McGrail, B.P., Icenhower, J.P. and Rodriguez, E.A., in Scientific Basis for Nuclear Waste Management XXV, edited by McGrail, B.P. and Gragnolino, G.A. (Mat. Res. Soc. Proc. 713, PA, 2002) pp. 537–546.Google Scholar
8. Lüttge, A., Bolton, E.W. and Lasaga, A.C., Am. J. Sci. 299, 652 (1999).Google Scholar