| Autor: |
Joanna Dziadkowiec, Shaghayegh Javadi, Matea Ban, Bjørn Jamtveit, Anja Røyne |
| Rok vydání: |
2022 |
| DOI: |
10.5194/egusphere-egu22-3016 |
| Popis: |
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. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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