Title

Topological Control on Silicates' Dissolution Kinetics

Abstract

Like many others, silicate solids dissolve when placed in contact with water. In a given aqueous environment, the dissolution rate depends on the composition and the structure of the solid and can span several orders of magnitude. Although the kinetics of dissolution depends on the complexities of both the dissolving solid and the solvent, a clear understanding of which structural descriptors of the solid control its dissolution rate is lacking. By pioneering dissolution experiments and atomistic simulations, we correlate the dissolution rates-ranging over 4 orders of magnitude-of a selection of silicate glasses and crystals to the number of chemical topological constraints acting between the atoms of the dissolving solid. The number of such constraints serves as an indicator of the effective activation energy, which arises from steric effects, and prevents the network from reorganizing locally to accommodate intermediate units forming over the course of the dissolution.

Department(s)

Materials Science and Engineering

Comments

The authors acknowledge full financial support for this research provided by The U.S. Department of Transportation (U.S. DOT) through the Federal Highway Administration (DTFH61-13-H-00011), the National Science Foundation (CMMI: 1066583 and CAREER Award: 1235269), The Oak Ridge National Laboratory operated for the U.S. Department of Energy by UT-Battelle (LDRD Award # 4000132990), and the University of California, Los Angeles (UCLA).

Keywords and Phrases

Activation energy; Silicates; Topology, Aqueous environment; Atomistic simulations; Dissolution kinetics; Dissolution rates; Effective activation energy; Orders of magnitude; Structural descriptors; Topological constraints, Dissolution

International Standard Serial Number (ISSN)

0743-7463; 1520-5827

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2016 American Chemical Society (ACS), All rights reserved.

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