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This article is cited in 3 scientific papers (total in 3 papers)
Finite ion size effects on electrolyte transport in nanofiltration membranes
Ilya I. Ryzhkova, Andrey V. Minakovb a Institute of Computational Modelling RAS SB,
Academgorodok, 50/44, Krasnoyarsk, 660036, Russia
b Institute of Engineering Physics and Radio Electronics,
Siberian Federal University, Svobodny, 79, Krasnoyarsk, 660041, Russia
Abstract:
The pressure-driven electrolyte transport through nanofiltration membrane pores with specified wall potential is investigated theoretically. The finite ion size effect is taken into account by introducing an additional term to electrochemical potential. The two-dimensional Navier–Stokes, Poisson, and modified Nernst–Planck equations are solved numerically in a high aspect ratio nanopore connecting two reservoirs with a larger diameter. The calculations are performed for potassium chloride aqueous solution. In the case of point-like ions, the non-physical rise of counter-ion concentration is observed near the pore wall at large applied voltages. When finite ion size is taken in account, the concentration of counter-ions decreases significantly and saturates to the maximum value. It leads to lower osmotic pressure jump and larger magnitude of potential in the pore. The stronger co-ion depletion observed for finite size ions results in the increase of salt rejection, membrane potential, and required pressure drop.
Keywords:
conductive membranes, electrolyte transport, nanofiltration, modified Nernst–Planck equation, finite ion size, numerical modelling.
Received: 25.10.2016 Received in revised form: 15.11.2016 Accepted: 10.02.2017
Citation:
Ilya I. Ryzhkov, Andrey V. Minakov, “Finite ion size effects on electrolyte transport in nanofiltration membranes”, J. Sib. Fed. Univ. Math. Phys., 10:2 (2017), 186–198
Linking options:
https://www.mathnet.ru/eng/jsfu539 https://www.mathnet.ru/eng/jsfu/v10/i2/p186
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