Aqueous electrolytes’ transport through nanopores of polymeric membrane

Abstract

Ion permeation and the selectivity of sodium and potassium ions through the nanopores of polyethylene terephthalate (PET) have been investigated at room temperature using the conductometric technique. The nanopores in PET with the high aspect ratio have been created using the ion track technology. The passive (due to the concentration gradient) and active transport (due to the applied potential) of aqueous electrolytes (i.e.; NaClO4 and KClO4 and their different combinations) has been studied. Along with the effect of concentration and electric field gradient, the effect of anion accumulation outside the nanopores on the transport of electrolytes has also been analysed using time series and current–voltage measurements. The transportation and selection of ions also depends on the hydration energy of the ions. A detailed study of transport of ions through the nanopores explains their I–V and I–t behaviour due to the inter- and intra- molecular interaction and their effective interaction with the walls of the nanopores.