Influence of medium polarity upon selectivity and efficiency of alkali metal cation sorption by polyether carboxylic acid resins

The influence of medium polarity upon competitive sorption of alkali-metal cations from aqueous and aqueous methanolic solutions by the polymethacrylic acid resin Amberlite CG-50, two acyclic polyether carboxylic acid resins, and six sym-(alkyl)dibenzo-16-crown-5-oxyacetic acid resins has been investigated. Addition of methanol was found to strongly depress the selective Li(+) sorption of CG-50 and one of the acyclic polyether carboxylic acid resins. Enhancement of metal ion-crown ether interactions as the percentage of methanol in the medium was increased accentuates the Na(+) sorption selectivity for the lariat ether carboxylic acid resins. The highest Na(+) sorption selectivity was obtained for sym-(alkyl)-dibenzo-16-crown-5-oxyacetic acid resins with ethyl and propyl groups in 80% methanol-20% water.