Photo driven ion transport and pumping through synthetic nanochannels

Abstract

Ion transport through synthetic ion channels has gained an important place in chemical and biotechnology and is being used in a broad range of applications. Swift heavy ion irradiation of Polyethylene terephthalate (PET) membrane of 12 μm thickness results in latent ion tracks which when etched by NaOH, leads to well defined synthetic channels with charged groups (−COO−) on the channel surface making them cation selective. In this study, these charged groups have been further functionalized with amine group to make them anion selective. These membranes with charged ion channels with different selectivity have been used for transport of the ions of different electrolytes (NaCl, KCl, NaClO4 and KClO4) through them. The effect of UV radiation on the transport of ions of these electrolytes through the channels has also been studied. Exposure to UV radiation affects the transport through the synthetic channels due to the change in the dissociation equilibrium. The effect of pH of the electrolyte(s) (having two molar concentrations 100 mM and 10 mM) during the UV exposure on the ion transport through cation (-carboxyl group) and anion (-amine group) selective membranes has also been studied.