New polymeric membrane incorporating a tetrapyrazolic macrocycle for the selective transport of cesium cation

Several Liquid membranes were examined for the selective separation and recovery of cesium cation. However, their instability over time and the low flux diffusion preventing for using them in practical industrial applications. Here is reported the synthesis of new stable polymeric membrane where a macrocycle containing two bipyrazolic subunits was covalently attached to a polymer support. This membrane was obtained by photopolymerisation of formulation that contained an active tetrapyrazolic macrocyclic monomer spread on a polyacrylonitrile support. The resulting membrane was stable over 20 cycles and it was applied for the facilitated transport of alkali metals (Li+, Na+, K+ and Cs+). It displayed a marked selectivity for transport of Cs+ with a flux diffusion of 58 · 10−3 mol h−1 m−2 in competitive transport against proton current. The selectivity (Cs+/K+) was 7.5 in favor of Cs+.