Preparation of chitosan-graft-benzo-15-crown-5 ether film for heavy metal ions separation

Abstract

a b s t r a c tChitosan-graft-benzo-15-crown-5 ether (CTS-g-B15C5) for metal ion separation was prepared and optimized by Box-Behnken design (BBD). Results showed that the maximum immobilization amount (I A ) of crown ether grafting on chitosan (CTS) polymer was 4.93 mmol·g -1 under the optimal conditions, which is in good agreement with the result predicted by BBD (4.97 mmol·g -1 ). Moreover, the CTS-g-B15C5 film exhibited an excellent adsorption ability and selectivity to different metal ions. The adsorption rates obtained by CTS-g-B15C5 film were 96.9% for Ag + and 94.3% for Pd 2+, which were higher than those obtained by CTS at the similar conditions. The order of adsorption ability on CTS-g-B15C5 . Furthermore, the CTS-g-B15C5 film could be reused after regeneration, and the adsorption rates for Ag + and Pd 2+ kept up to 90% after being regenerated for five times, which suggests a good stability and potential application in heavy metal recycling field.

Effects of Grafting Azacrown Ether on Thermal and Swelling Properties of Chitosan Films

“…However, Ch is soluble in acid media and must therefore be crosslinked for these application. The selective chelating properties exhibited by crown ethers towards metal ions have led to their incorporation into chitosan polymer matrices to improve capacity for metal ion adsorption [1][2][3], enhance selective pollutant removal [4,5], and thus wastewater remediation [6,7]. While many authors have chemically modified crosslinked chitosan with crown ethers [5,6,[8][9][10][11][12][13][14][15][16][17], and shown the advantage of combining crown ethers with chitosan [5,8,9,18,19], only a few have used the crown ether as the crosslinker for chitosan [7,18,[20][21][22][23][24] and fewer have used the nitrogen containing azacrown ethers [25].…”