1
|
Whittaker ML, Shoaib M, Lammers LN, Zhang Y, Tournassat C, Gilbert B. Smectite phase separation is driven by hydration-mediated interfacial charge. J Colloid Interface Sci 2023; 647:406-420. [PMID: 37269737 DOI: 10.1016/j.jcis.2023.05.085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 05/08/2023] [Accepted: 05/14/2023] [Indexed: 06/05/2023]
Abstract
Smectite clay minerals have an outsize impact on the response of clay-rich media to common stimuli, such as hydration and ion exchange, motivating extensive effort to understand behaviors resulting from these processes such as swelling and exfoliation. Smectites are common and historic systems for investigating colloidal and interfacial phenomena, with two swelling regimes commonly identified across myriad clays: osmotic swelling at high water activity and crystalline swelling at low water activity. However, no current swelling model seamlessly spans the full ranges of water, salt and clay content encountered in natural or engineered settings. Here, we show that structures previously rationalized as either osmotic or crystalline coexist as a rich array of distinct colloidal phases that differ by water content, layer stacking thickness, and curvature. We present an analytical model for intermolecular potentials among water, salt and clay in both mono- and divalent electrolytes that predicts swelling pressures across high and low water activities. Our results indicate that all clay swelling is osmotic swelling, but that the osmotic pressure of charged mineral interfaces becomes attractive and dominates that of the electrolyte at high clay activities. Global energy minima are often not reached on experimental timescales due to many local energy minima that promote long-lived intermediate states with vast differences in clay, ion, and water mobilities, leading to hyperdiffusive layer dynamics driven by variable hydration-mediated interfacial charge. Teaser Distinct colloidal phases of swelling clays emerge via ion (de)hydration at mineral interfaces that drives hyperdiffusive layer dynamics as metastable smectites approach equilibrium.
Collapse
Affiliation(s)
- Michael L Whittaker
- Energy Geosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Department of Earth and Planetary Science, University of California, Berkeley, CA 94720, USA.
| | - Mohammad Shoaib
- Energy Geosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Laura N Lammers
- Energy Geosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Department of Environmental Science, Policy and Management, University of California, Berkeley, CA 94720, USA
| | - Yugang Zhang
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Christophe Tournassat
- Energy Geosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Institut des Sciences de la Terre d'Orléans, Université d'Orléans-CNRS-BRGM, Orléans 45071, France
| | - Benjamin Gilbert
- Energy Geosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Department of Earth and Planetary Science, University of California, Berkeley, CA 94720, USA
| |
Collapse
|
2
|
Whittaker ML, Ren D, Ophus C, Zhang Y, Waller L, Gilbert B, Banfield JF. Ion complexation waves emerge at the curved interfaces of layered minerals. Nat Commun 2022; 13:3382. [PMID: 35697675 PMCID: PMC9192655 DOI: 10.1038/s41467-022-31004-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 05/30/2022] [Indexed: 11/11/2022] Open
Abstract
Visualizing hydrated interfaces is of widespread interest across the physical sciences and is a particularly acute need for layered minerals, whose properties are governed by the structure of the electric double layer (EDL) where mineral and solution meet. Here, we show that cryo electron microscopy and tomography enable direct imaging of the EDL at montmorillonite interfaces in monovalent electrolytes with ångstrom resolution over micron length scales. A learning-based multiple-scattering reconstruction method for cryo electron tomography reveals ions bound asymmetrically on opposite sides of curved, exfoliated layers. We observe conserved ion-density asymmetry across stacks of interacting layers in cryo electron microscopy that is associated with configurations of inner- and outer-sphere ion-water-mineral complexes that we term complexation waves. Coherent X-ray scattering confirms that complexation waves propagate at room-temperature via a competition between ion dehydration and charge interactions that are coupled across opposing sides of a layer, driving dynamic transitions between stacked and aggregated states via layer exfoliation. The structure of hydrated interfaces is essential for understanding of geochemical processes and behavior of layered minerals. The authors show that waves of hydrated ions emerge at curved aqueous interfaces and couple mineral deformation to the chemistry of the solution.
Collapse
Affiliation(s)
- Michael L Whittaker
- Energy Geosciences Division, Lawrence Berkeley National Laboratory, 94720, Berkeley, CA, USA. .,Department of Earth and Planetary Science, University of California, 94720, Berkeley, CA, USA.
| | - David Ren
- Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, CA, 94720, USA
| | - Colin Ophus
- National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, 94720, Berkeley, CA, USA
| | - Yugang Zhang
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Laura Waller
- Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, CA, 94720, USA
| | - Benjamin Gilbert
- Energy Geosciences Division, Lawrence Berkeley National Laboratory, 94720, Berkeley, CA, USA.,Department of Earth and Planetary Science, University of California, 94720, Berkeley, CA, USA
| | - Jillian F Banfield
- Energy Geosciences Division, Lawrence Berkeley National Laboratory, 94720, Berkeley, CA, USA.,Department of Earth and Planetary Science, University of California, 94720, Berkeley, CA, USA
| |
Collapse
|
3
|
A strength inversion origin for non-volcanic tremor. Nat Commun 2022; 13:2311. [PMID: 35484154 PMCID: PMC9050742 DOI: 10.1038/s41467-022-29944-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Accepted: 03/16/2022] [Indexed: 11/13/2022] Open
Abstract
Non-volcanic tremor is a particularly enigmatic form of seismic activity. In its most studied subduction zone setting, tremor typically occurs within the plate interface at or near the shallow and deep edges of the interseismically locked zone. Detailed seismic observations have shown that tremor is composed of repeating small low-frequency earthquakes, often accompanied by very-low-frequency earthquakes, all involving shear failure and slip. However, low-frequency earthquakes and very-low-frequency earthquakes within each cluster show nearly constant source durations for all observed magnitudes, which implies characteristic tremor sub-event sources of near-constant size. Here we integrate geological observations and geomechanical lab measurements on heterogeneous rock assemblages representative of the shallow tremor region offshore the Middle America Trench with numerical simulations to demonstrate that these tremor events are consistent with the seismic failure of relatively weaker blocks within a stronger matrix. In these subducting rocks, hydrothermalism has led to a strength-inversion from a weak matrix with relatively stronger blocks to a stronger matrix with embedded relatively weaker blocks. Tremor naturally occurs as the now-weaker blocks fail seismically while their surrounding matrix has not yet reached a state of general seismic failure. Subduction plate boundaries have enigmatic seismic tremor that is often associated with surges in creep across these boundaries. Here, the authors use multiple approaches to show how blocks of weak rocks in a stronger matrix can explain both the occurrence and characteristics of tremor events.
Collapse
|
4
|
Kaneki S, Hirono T. Diagenetic and shear-induced transitions of frictional strength of carbon-bearing faults and their implications for earthquake rupture dynamics in subduction zones. Sci Rep 2019; 9:7884. [PMID: 31133653 PMCID: PMC6536680 DOI: 10.1038/s41598-019-44307-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 05/14/2019] [Indexed: 11/08/2022] Open
Abstract
Subduction-related diagenetic reactions affect fault strength and are thus important for understanding earthquake rupture dynamics in subduction zones. Carbonaceous material (CM) is found worldwide in active plate-boundary and intracontinental faults, yet the effect of its transformation on frictional strength and rupture dynamics remains unknown. We conducted high-velocity friction experiments together with organochemical analyses on CM in the form of lignite, bituminous coal, anthracite and graphite. Results clearly show that an increase in CM maturity and crystallinity leads to a decrease in the peak friction coefficient (from 0.5 to 0.2). We also infer that friction applied to low-grade CM increases its maturity, but friction applied to high-grade CM reduces its maturity. These findings suggest that both diagenetic and shear-induced transformations of CM strongly affect the frictional strength of CM-bearing faults, potentially affecting the depth-dependences of frictional strength and rupture dynamics on plate-subduction faults.
Collapse
Affiliation(s)
- Shunya Kaneki
- Department of Earth and Space Science, Graduate School of Science, Osaka University, Toyonaka, Osaka, 560-0043, Japan.
- Disaster Prevention Research Institute, Kyoto University, Uji, Kyoto, 611-0011, Japan.
| | - Tetsuro Hirono
- Department of Earth and Space Science, Graduate School of Science, Osaka University, Toyonaka, Osaka, 560-0043, Japan
| |
Collapse
|