Durability of membranes containing uranyl salophenes

Potentiometric, spectroscopic and microscopic studies concerning polymer membranes based on uranyl salophenes were performed. Uranyl salophenes—group of Schiff base complexes—revealed very good recognition abilities toward some hydrophilic anions and appeared to be very promising ionophores for phosphate-selective electrodes. The influence of the ionophore structure and polymer matrix composition on the durability and selectivity of PVC based membrane of phosphate-selective electrodes was investigated. The interaction of uranyl salophenes with water and Cl−, NO3−, H2PO4− anions was examined. When the membranes were conditioned in phosphate solution, the formation of a water–UO2–salophene complex, insoluble in both water and organic phase, and next the decomposition of the ionophore occurred. These results gave the explanation of the mechanism of deterioration of phosphate-selective membranes.