Selective carrier-mediated cesium transport through polymer inclusion membranes by calix[4]arene-crown-6 carriers from complex aqueous mixtures

Competitive Cs⁺ ion transport by polymer inclusion membranes (PIMs) with bis(dodecyloxy)calix[4]arenecrown-6 or calix[4]arene-biscrown-6 was investigated under various conditions. The PIM matrix consisted of cellulose triacetate and ortho-nitrophenyloctyl ether. Special attention was paid to PIM performance employing complex source-phase mixtures, including simulant solutions of acidic nuclear wastes present at Idaho National Engineering and Environmental Laboratory. PIMs exhibited highly efficient and selective Cs⁺ transport under competitive conditions. Membranes containing calix-monocrown carrier exhibited slightly less efficient but more selective Cs⁺ transport than those with calix-biscrown carrier. PIMs with bis(dodecyloxy)calix[4]arene-crown-6 exhibited excellent stability in terms of carrier loss to the aqueous phase. The variation of cesium transport with composition of aqueous phase was adequately described by a diffusion-limited transport model.