Synthesis and evaluation of chitosan aryl azacrown ethers as adsorbents for metal ions

New azacrown ether chitosan derivatives (CTS–OC, CTS–NC) were synthesized by reaction of aryl mesocyclic diamine with the C6 hydroxyl group or C2 amino group in chitosan. Their structures were confirmed by elemental analysis, infrared spectra analysis, and X-ray diffraction analysis. The adsorption and selectivity properties of the aryl azacrown ethers chitosan derivatives for Hg2+, Cd2+, Pb2+, Ag+, and Cr3+ were also investigated. The experimental results showed that the two chitosan–azacrown ethers have good adsorption capacity for Pb2+, Cd2+, and Hg2+. The adsorption capacity of CTS–OC are higher than that of CTS–NC for Pb2+ and Cd2+. The chitosan–azacrown ethers have high selectivity for the adsorption of Pb2+ and Hg2+ with the coexistence of Cd2+. The selectivity properties of CTS–OC are better than those of CTS–NC. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 3093–3098, 2000