Concentration polarization is a fundamental phenomenon that occurs at charge-selective interfaces, such as electrode surfaces and micro or nanochannel interfaces. The concentration gradient at a nanoscale interface, well known to differ from macroscopic double layer, induces many important and fascinating phenomena. Interesting pinched hysteresis loops with a non-zero cross point are found in current-potential curves in the study of the ionic transport through single conical nanopore under a cyclic sweeping potential. The accumulated charges in each hysteresis loop are quantified under different potential scan rates or in different electrolyte concentrations. Both experimental and theoretical results show that this concentration polarization process can be described by simple in-series RC equivalent circuits. The calculated polarized charge distribution quantifies the concentration polarization at nanoscale interfaces, which has been applied in various fields such as molecular concentrator, precipitation or crystallization, sensing and separation.

Ion concentration polarization in single conical nanopores: Charge balance at nanoscale interfaces

245th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.