Abstract
We report measurements of the zeta potential of natural sandstones saturated with NaCl electrolytes of varying ionic strengths at temperatures up to 150°C. The zeta potential is always negative but decreases in magnitude with increasing temperature at low ionic strength (0.01 M) and is independent of temperature at high ionic strength (0.5 M). The pH also decreases with increasing temperature at low ionic strength but remains constant at high ionic strength. The temperature dependence of the zeta potential can be explained by the temperature dependence of the pH. Our findings are consistent with published models of the zeta potential, so long as the temperature dependence of the pH at low ionic strength is accounted for and can explain the hitherto contradictory results reported in previous studies.
Original language | English |
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Pages (from-to) | 6287-6294 |
Number of pages | 8 |
Journal | Geophysical Research Letters |
Volume | 42 |
Issue number | 15 |
Early online date | 13 Aug 2015 |
DOIs | |
Publication status | Published - 16 Aug 2015 |
Bibliographical note
Supporting data are included in PDF and CSV files; any additional data may be obtained from the corresponding author (e-mail: j.vinogradov@imperial.ac.uk). TOTAL is thanked for partial support of Jackson's Chair in Geological Fluid Mechanics and for supporting the activities of the TOTAL Laboratory for Reservoir Physics at Imperial College London where these experiments were conducted.The Editor thanks Andre Revil and Paul Glover for their assistance in evaluating this paper.
Keywords
- zeta potential
- surface charge
- elevated temperatures
- intact sandstones
- potable water
- seawater
- pH