EMULSIFICATION OF CALIX[4]ARENES BEARING 4 CHAINS AND TRANSPORTATION OF CESIUM ION THROUGH LIQUID SURFACTANT MEMBRANE

Resorcinol-type calix[4]arenes bearing four alkyl side chains ([4]Ar-R (n)) have been applied as a liquid surfactant-membrane in the concentr ation process of Cs+. [4]Ar-R(n) formed a highly stable water-in-oil ( w/o) emulsion for a mixture of toluene and HCl solution, and the w/o e mulsion became a w/o/w emulsion by stirring it in a Cs+ solution. The Cs+ in the outer aqueous solution was transported through the liquid s urfactant-membrane of w/o/w emulsion into the inner HCl solution. [4]A r-R(6) was the most effective emulsifier capable carrying Cs+ in the [ 4]Ar-R(n) bearing alkyl chains of various lengths. The final amount of the transported Cs+ was 9 times as much as the molar of [4]Ar-R(6) in 100 min at the initially 10 times molar Cs+ in the outer solution (tu rnover number: 9). Moreover, the Cs+ was transported selectively from a mixture of alkali metal ions (Cs+, Na+, and K+) by using 2x10(-4) mo l of [4]Ar-R(6).