Ionic transport through sub-10 nm diameter hydrophobic high-aspect ratio nanopores: experiment, theory and simulation
| Autor: | Balme, Sébastien, Picaud, Fabien, Manghi, Manoel, Palmeri, John, Bechelany, Mikhael, Cabello-Aguilar, Simon, Abou-Chaaya, Adib, Miele, Philippe, Balanzat, Emmanuel, Janot, Jean Marc |
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| Rok vydání: | 2015 |
| Předmět: | |
| Zdroj: | Scientific Reports vol. 5, 10135 (2015) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1038/srep10135 |
| Popis: | Fundamental understanding of ionic transport at the nanoscale is essential for developing biosensors based on nanopore technology and new generation high-performance nanofiltration membranes for separation and purification applications. We study here ionic transport through single putatively neutral hydrophobic nanopores with high aspect ratio (of length L=6 \mu m with diameters ranging from 1 to 10 nm) and with a well controlled cylindrical geometry. We develop a detailed hybrid mesoscopic theoretical approach for the electrolyte conductivity inside nanopores, which considers explicitly ion advection by electro-osmotic flow and possible flow slip at the pore surface. By fitting the experimental conductance data we show that for nanopore diameters greater than 4 nm a constant weak surface charge density of about 10$^{-2}$ C m$^{-2}$ needs to be incorporated in the model to account for conductance plateaus of a few pico-Siemens at low salt concentrations. For tighter nanopores, our analysis leads to a higher surface charge density, which can be attributed to a modification of ion solvation structure close to the pore surface, as observed in the molecular dynamics simulations we performed. Comment: 14 pages, Supplementary information available on request |
| Databáze: | arXiv |
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