Cs+ and Sr2+ are selectively removed over Na+ from acidic aqueous solutions with high Na+ concentrations by using membranes designed to selectively transport one of the two cations. To this end, calix[4]arene derivatives were used as carriers in polymer inclusion membranes (PIMs). The synthesis and characterization of new calix[4]arene derivatives (a bisamide (2) and three bisesters (3, 5 and 6)) used for the separation of Sr2+ are described. Another bisester (4) was employed for the same separation. In addition, a calix[4]arene-crown-6 (7) was incorporated into the membrane for Cs+ extraction. The concentration of each membrane component (polymer, carrier and counter-ion) was optimized and the permeability coefficients (P, m sec(-1)) of Cs+, Sr2+ and Nat were determined. A synergistic effect between the calixarenes and dinonylnaphtalenesulfonic acid, used as counterion, (DNNS, 8) was observed. High selectivity of Cs+ over Na+ and of Sr2+ over Na+ were obtained with compounds 7 and 3, respectively. The best P for Sr2+ was obtained with compound 4. A long-term experiment was carried out to demonstrate the durability of PIMs. PIMs are compared to classical supported liquid membranes.
Cs+ and Sr2+ are selectively removed over Na+ from acidic aqueous solutions with high Na+ concentrations by using membranes designed to selectively transport one of the two cations. To this end, calix[4]arene derivatives were used as carriers in polymer inclusion membranes (PIMs). The synthesis and characterization of new calix[4]arene derivatives (a bisamide (2) and three bisesters (3, 5 and 6)) used for the separation of Sr2+ are described. Another bisester (4) was employed for the same separation. In addition, a calix[4]arene-crown-6 (7) was incorporated into the membrane for Cs+ extraction. The concentration of each membrane component (polymer, carrier and counter-ion) was optimized and the permeability coefficients (P, m sec(-1)) of Cs+, Sr2+ and Nat were determined. A synergistic effect between the calixarenes and dinonylnaphtalenesulfonic acid, used as counterion, (DNNS, 8) was observed. High selectivity of Cs+ over Na+ and of Sr2+ over Na+ were obtained with compounds 7 and 3, respectively. The best P for Sr2+ was obtained with compound 4. A long-term experiment was carried out to demonstrate the durability of PIMs. PIMs are compared to classical supported liquid membranes.
Selective Transport Of Cesium And Strontium Ions Through Polymer Inclusion Membranes Containing Calixarenes As Carriers
ARENA, Giuseppe;CONTINO, Annalinda;SCIOTTO, Domenico;
1998-01-01
Abstract
Cs+ and Sr2+ are selectively removed over Na+ from acidic aqueous solutions with high Na+ concentrations by using membranes designed to selectively transport one of the two cations. To this end, calix[4]arene derivatives were used as carriers in polymer inclusion membranes (PIMs). The synthesis and characterization of new calix[4]arene derivatives (a bisamide (2) and three bisesters (3, 5 and 6)) used for the separation of Sr2+ are described. Another bisester (4) was employed for the same separation. In addition, a calix[4]arene-crown-6 (7) was incorporated into the membrane for Cs+ extraction. The concentration of each membrane component (polymer, carrier and counter-ion) was optimized and the permeability coefficients (P, m sec(-1)) of Cs+, Sr2+ and Nat were determined. A synergistic effect between the calixarenes and dinonylnaphtalenesulfonic acid, used as counterion, (DNNS, 8) was observed. High selectivity of Cs+ over Na+ and of Sr2+ over Na+ were obtained with compounds 7 and 3, respectively. The best P for Sr2+ was obtained with compound 4. A long-term experiment was carried out to demonstrate the durability of PIMs. PIMs are compared to classical supported liquid membranes.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
