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- Ionic transport through sub-10 nm diameter hydrophobic high-aspect ratio nanopores: experiment, theory and simulation doi link

Auteur(s): Balme Sébastien, Picaud Fabien, Manghi Manoel, Palmeri J., Bechelany Mikhael, Cabello-Aguilar Simon, Abou Chaaya Adib, Miele Philippe, Balanzat Emmanuel, Janot Jean-Marc

(Article) Publié: Scientific Reports, vol. 5 p.10135 (2015)
Texte intégral en Openaccess : openaccess


Ref HAL: hal-01162029_v1
DOI: 10.1038/srep10135
WoS: 000355647800001
Exporter : BibTex | endNote
45 Citations
Résumé:

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 μm 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.