Abstract:

Chemical and structural transformations of minerals and rocks during fluid interactions are important in both natural processes, such as weathering and trace element uptake, and energy-related applications, including nuclear waste disposal, geothermal energy, and catalysis. A fundamental, quantitative understanding of mineral-fluid interactions, particularly the effects of porosity, grain boundaries, and impurities on reaction rates, is essential to be able to accurately predict reaction rates but remains incomplete. Currently discrepancies of several orders of magnitude are being observed between mineral reaction rates observed in the field and laboratory which point to a lack of understanding of what controls reactivity at solid/liquid interfaces.

This presentation will address two topics: (1) MgO-based mineral looping reactions for separating gas mixtures and (2) the influence of microstructure on rock-fluid interactions. I will cover amorphous phase formation, in situ film formation during MgO carbonation and hydration and impurity and microstructure effects on reactivity. These insights highlight the interplay between mineral structure, fluid interactions, and reactivity, with implications for robust predictions of reaction and transport rates across diverse applications.

Bio:

Juliane Weber is a R&D staff member in the Geochemistry and Interfacial Sciences Group at Oak Ridge National Laboratory. Since completing her Ph.D. in geochemistry in 2017 (RWTH Aachen University, Germany), she was a postdoctoral researcher in the Geochemistry and Interfacial Sciences Group at ORNL from 2017-2019, and an associate staff scientist at the Kuiper Materials Imaging and Characterization Facility of the Lunar and Planetary Laboratory at the University of Arizona from 2019-2020. From 2020-2024, she was an associate R&D staff member at ORNL before being promoted to her current position of R&D staff member.

Her research focuses on understanding how defects, microstructure and environmental factors influence reactions at solid/liquid or solid/gas interfaces. For this, she combines neutron and synchrotron-based X-ray scattering techniques with advanced microscopy and in-situ observations. Since 2022, she is the principal investigator of a project funded by the Department of Energy Basic Energy Sciences Material Sciences and Engineering program focused on interfacial reactivity.