Diffusion of Na+ and Rb+ in a polymeric crown ether

Abstract

The atomic transport of Na⁺ and Rb⁺ in the poly(crown ether) poly(dibenzo-18-crown-6), has been studied as well as the thermodynamics of absorption and desorption using radioactive techniques with radiotracers ²²Na and ⁸⁶Rb. All the experiments show that this is a good material for ion-exchange applications, since it shows (1) fast kinetics of absorption, (2) a high capacity (one cation per four monomeric units) and (3) complete reversibility. However, no selective effect is found between Na⁺ and Rb⁺.