Movement of ions, water and non-electrolytes has been measured through narrow pores etched in polyethyleneterephthalate (PETP) membranes previously ‘tracked’ by bombardment with heavy ions. Pore size estimated from flow of water, ions and non-electrolytes is in reasonable agreement with that obtained by a polymer exclusion assay. Flow of ions through narrow pores exhibits characteristic features: i) rapid switching between high- and low- conducting states; ii) selectivity between different ions; iii) inhibition by protons or divalent cations with order of efficacy H+>Zn2+>Ca2+>Mg2+. Ion current and selectivity are reduced when the carboxyl groups lining the pore are methylated. The characteristic features of ion flow in narrow pores arise from the nature of the flow of ions close to a surface bearing fixed charges of the opposite sign.
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.