Projects per year
Abstract
Ion transport in nanoconfinement differs from that in bulk and has been extensively researched across scientific and engineering disciplines 1–4 . For many energy and water applications of nanoporous materials, concentration-driven ion diffusion is simultaneously subjected to a local electric field arising from surface charge or an externally applied potential. Due to the uniquely crowded intermolecular forces under severe nanoconfinement (<2 nm), the transport behaviours of ions can be influenced by the interfacial electrical double layer (EDL) induced by a surface potential, with complex implications, engendering unusual ion dynamics 5–7 . However, it remains an experimental challenge to investigate how such a surface potential and its coupling with nanoconfinement manipulate ion diffusion. Here, we exploit the tunable nanoconfinement in layered graphene-based nanoporous membranes to show that sub-2 nm confined ion diffusion can be strongly modulated by the surface potential-induced EDL. Depending on the potential sign, the combination and concentration of ion pairs, diffusion rates can be reversibly modulated and anomalously enhanced by 4~7 times within 0.5 volts, across a salt concentration gradient up to seawater salinity. Modelling suggests that this anomalously enhanced diffusion is related to the strong ion–ion correlations under severe nanoconfinement, and cannot be explained by conventional theoretical predictions.
Original language | English |
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Pages (from-to) | 685-690 |
Number of pages | 6 |
Journal | Nature Nanotechnology |
Volume | 13 |
Issue number | 8 |
DOIs | |
Publication status | Published - Aug 2018 |
Projects
- 1 Finished
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ARC Centre of Excellence in Convergent Bio-Nano Science and Technology
Davis, T. (Primary Chief Investigator (PCI)), Boyd, B. (Chief Investigator (CI)), Bunnett, N. (Chief Investigator (CI)), Porter, C. (Chief Investigator (CI)), Caruso, F. (Chief Investigator (CI)), Kent, S. (Chief Investigator (CI)), Thordarson, P. (Chief Investigator (CI)), Kearnes, M. (Chief Investigator (CI)), Gooding, J. (Chief Investigator (CI)), Kavallaris, M. (Chief Investigator (CI)), Thurecht, K. J. (Chief Investigator (CI)), Whittaker, A. K. (Chief Investigator (CI)), Parton, R. (Chief Investigator (CI)), Corrie, S. R. (Chief Investigator (CI)), Johnston, A. (Chief Investigator (CI)), McGhee, J. (Chief Investigator (CI)), Greguric, I. D. (Partner Investigator (PI)), Stevens, M. M. (Partner Investigator (PI)), Lewis, J. S. (Partner Investigator (PI)), Lee, D. S. (Partner Investigator (PI)), Alexander, C. (Partner Investigator (PI)), Dawson, K. (Partner Investigator (PI)), Hawker, C. (Partner Investigator (PI)), Haddleton, D. (Partner Investigator (PI)), Thierry, B. (Chief Investigator (CI)), Prestidge, C. A. (Chief Investigator (CI)), Meyer, A. (Project Manager), Jones-Jayasinghe, N. (Project Manager), Voelcker, N. (Chief Investigator (CI)), Nann, T. (Chief Investigator (CI)) & McLean, K. (Partner Investigator (PI))
Australian Research Council (ARC), Monash University, University of Melbourne, University of New South Wales (UNSW), University of Queensland , University of South Australia, Monash University – Internal Faculty Contribution, University of Wisconsin Madison, Memorial Sloan Kettering Cancer Center, University of California System, University College Dublin, Imperial College London, University of Warwick, Sungkyunkwan University, Australian Nuclear Science and Technology Organisation (ANSTO) , University of Nottingham
30/06/14 → 29/06/21
Project: Research