NanoDay 2020 Poster 15 – Jay Ken

Click to Enter the Poster Zoom Room: Poster 15 Zoom Link or Return to Poster Session 2 List

Ion-Exchange Selectivity of Polycarbonate Nanopore Membranes

Jay Ken

Authors: Jay Ken, Stevie Bush, Charles Martin

Faculty Mentor: Charles Martin, PhD

College: College of Liberal Arts and Sciences

Department: Chemistry


Polycarbonate (PC) membranes containing cylindrical nanopores that span the entire thickness of the membrane show cation permselective transport similar to that observed in ion-exchange polymers. Cation permselectivity is observed due to the negatively charged carboxylate surface groups along the surface of the nanopores. These membranes reject anions and transport only cations. Here, we characterize the ion-exchange selectivity of the PC membrane by determining the potentiometric selectivity coefficients. In real-life measurements that include complex matrices, the PC membrane’s response to a primary ion can be affected by interfering ions. Correction for this interfering ionic response needs to be taken into consideration for accurate analysis and effective separation. This requires that ionic permselectivity of the PC membrane filters be quantified. The potentiometric selectivity coefficient expresses the ability of the membrane to respond primarily to the reference ion in the presence of competing, interfering ions. We describe here potentiometric selectivity coefficients for a variety of competing cations against a Cs+ reference ion. Several mechanisms are described that affect the selectivity coefficient and the PC membrane’s ability to effectively separate cations including hydrophobicity and ion-pair formation.


Poster Pitch