Mineral Reactivity and Transformations in Adsorbed Water Films
EMSL Project ID
48820
Abstract
Transformations of minerals covered in thin films of adsorbed H2O are ubiquitous in nature and occur under unique chemical and physical constraints. But in contrast to bulk aqueous systems, fundamental understanding of reaction pathways at these mineral/fluid interfaces is lacking. We propose a comprehensive experimental and theoretical investigation to identify and understand key processes that control reactions in systems of minerals covered in adsorbed H2O films, with emphasis on surface complexation, dissolution, transport, nucleation, and growth. Our primary model system will be silicate transformation to metal carbonates under geochemically relevant temperatures and pressures. We will focus on reactivity in wet scCO2 as an important but poorly understood natural and anthropogenic fluid. Our research will integrate the singular capabilities in EMSL, including one-of-a-kind in situ experimental techniques with world-class theoretical and molecular computational approaches. Mineral surfaces will be probed using new in situ high-pressure NMR and IR spectroscopy as well as new in situ X-Ray diffraction methods. Ex situ samples will be examined using XPS, XRD, SEM, FIB-TEM, and new atom probe tomography (APT). MD simulations and molecular electronic structure simulations are proposed to investigate the underlying causes of threshold reactivity in adsorbed H2O films and to help interpret experimental spectra to determine the structures of possible prenucleation complexes and monomeric units for mineral growth. Our results will be broadly relevant to not just high-pressure, low-water scCO2 systems, but also other fluids undersaturated with H2O over a range of pressures, including below ambient.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2015-10-01
End Date
2017-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Co-Investigator(s)
Team Members
Related Publications
Ilgen AG, RK Kukkadapu, DR Dunphy, K Artyushkova, JM Cerrato, JN Kruichak, M Janish, CJ Sun, JM Argo, and RE Washington. 2017. "Synthesis and characterization of redox-active ferric nontronites." Chemical Geology 470:1-12. doi:10.1016/j.chemgeo.2017.07.010
McGrail BP, HT Schaef, FA Spane, JB Cliff, III, O Qafoku, JA Horner, CJ Thompson, AT Owen, and EC Sullivan. 2017. "Field Validation of Supercritical CO2 Reactivity with Basalts." Environmental Science & Technology Letters 4(1):6-10. doi:10.1021/acs.estlett.6b00387
Schaef HT, N Loganathan, GM Bowers, RJ Kirkpatrick, AO Yazaydin, SD Burton, DW Hoyt, S Thanthiriwatte, DA Dixon, BP McGrail, KM Rosso, ES Ilton, and JS Loring. 2017. "Tipping Point for Expansion of Layered Aluminosilicates in Weakly Polar Solvents: Supercritical CO2." ACS Applied Materials & Interfaces (9):36783?36791. doi:10.1021/acsami.7b10590