Hydration and Hydroxylation of MgO in Solution: NMR Identification of Proton-Containing Intermediate Phases.

ABSTRACT: Magnesium oxide (MgO)-engineered barriers used in subsurface applications will be exposed to high concentration brine environments and may form stable intermediate phases that can alter the effectiveness of the barrier. To explore the formation of these secondary intermediate phases, MgO was aged in water and three different brine solutions and characterized with X-ray diffraction (XRD) and ¹H magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy. After aging, there is ∼4% molar equivalent of a hydrogen-containing species formed. The ¹H MAS NMR spectra resolved multiple minor phases not visible in XRD, indicating that diverse disordered proton-containing environments are present in addition to crystalline Mg(OH)₂ brucite. Density function

SUBMITTER: Rimsza JM 

PROVIDER: S-EPMC6648527 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature