EGU22-3016
https://doi.org/10.5194/egusphere-egu22-3016
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Ion-dependent adhesion between calcite surfaces

Joanna Dziadkowiec1, Shaghayegh Javadi1, Matea Ban2, Bjørn Jamtveit1, and Anja Røyne1
Joanna Dziadkowiec et al.
  • 1University of Oslo, NJORD Centre, Department of Physics, Norway (joanna.dziadkowiec@fys.uio.no)
  • 2Materials Testing Institute, University of Stuttgart, Germany

Disjoining pressure that operates between mineral surfaces in fluid-filled granular rocks is often strongly influenced by the ionic composition of pore solutions. Can various ionic species exhibit a remarkably different influence on the mineral adhesion and thus the cohesion within granular rocks? We explore this question in atomic force microscopy (AFM) experiments using two brittle calcite surfaces in a symmetrical surface configuration. Our AFM results show a robust difference between the adhesion in the presence of Na+ and Ca2+ ions. The adhesion is significantly higher for monovalent Na+ at a given ionic strength in comparison to more hydrated divalent Ca2+ cations. In addition, the adhesive forces are weakly modulated by the varying Ca2+ concentration. We thus infer that for weakly charged minerals such as calcite, Ca2+ can sustain relatively high positive disjoining pressures and thus thicker water films between the contacting mineral grains.

How to cite: Dziadkowiec, J., Javadi, S., Ban, M., Jamtveit, B., and Røyne, A.: Ion-dependent adhesion between calcite surfaces, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-3016, https://doi.org/10.5194/egusphere-egu22-3016, 2022.

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