Abstract
Mineral growth and dissolution are often treated as occurring via a single reversible process that governs the rate of reaction. We show that multiple distinct intermediate states can occur during both growth and dissolution. Specifically, we used metadynamics, a method for efficiently exploring the free-energy landscape of a system, coupled to umbrella sampling and reactive flux calculations to examine the mechanism and rates of attachment and detachment of a barium ion onto a stepped barite (BaSO 4) surface. The activation energies calculated for the rate-limiting reactions, which are different for attachment and detachment, precisely match those measured experimentally during both growth and dissolution. These results can potentially explain anomalous non-steady-state mineral reaction rates observed experimentally and will enable the design of more efficient growth inhibitors and facilitate an understanding of the effect of impurities.
Original language | English |
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Pages (from-to) | 11-14 |
Number of pages | 4 |
Journal | Journal of the American Chemical Society |
Volume | 134 |
Issue number | 1 |
DOIs | |
State | Published - Jan 11 2012 |