Inclusion extraction of alkali metals by emulsion liquid membranes bearing nano-baskets

Abstract

Nano-assisted inclusion separation of alkali metals from basic solutions was reported by inclusion-facilitated emulsion liquid membrane process. The novelty and significance of this study is application of nano-baskets of calixarene in the selective and efficient separation of alkali metals, as both carrier and surfactant. For this aim, four derivatives of p-tert-calix[4]arene bearing different sulfonamide moieties were synthesized and their inclusion-extraction parameters were optimized. Maximum extraction was achieved using calixarene scaffold 03 (3.45 × 10−2 M) as carrier/demulsifier, commercial kerosene as diluent in membrane, sulphonic acid (0.2 M) and ammonium carbonate (0.4 M) as the strip and the feed phases, the phase and the treat ratios of 0.8 and 0.3, mixing speed (300 rpm), and initial solute concentration (100 mg/L). The selectivity of membrane over more than ten interfering cations was examined and the results reveled that under the optimized operating conditions, the extraction percent of alkali metals was 98–99 %.