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Updated: Mar 29, 2026

Merging Ion Concentration Polarization between Juxtaposed Ion Exchange Membranes to Block the Propagation of the Polarization Zone
Published on: February 23, 2017
Highly efficient charge inversion in dense periodic nanoporous framework membranes
Yan Wang1,2, Shixian Xin2, Keyi Yang1
1College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, P.R. China. ypfeng@buct.edu.cn.
Abstract:
Charge inversion (overscreening), a counterintuitive electrokinetic phenomenon, provides a pivotal pathway for manipulating ion selectivity in nanofluidic systems. Here, we show that this effect can be realized in a covalent organic framework (COF) membrane modulated solely by monovalent cations, enabling a reversible switch from cation to anion selectivity. Our findings indicate that the inversion behavior stems from a notably high saturated ion adsorption capacity that may be facilitated by synergistic pore-pore interactions at ultrahigh pore density, along with nanoconfined steric hindrance within the COF pores.
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