Journal of Applied Polymer Science, Vol.108, No.3, 2017-2022, 2008
Effect of the nature of crosslinking agent on the unusual metal ion specificity and selectivity of N,N-bis(2-aminoethyl)polyacrylamide
Metal ion desorbed crosslinked N,N-bis(2-aminoethyl)polyacrylamides showed enhanced specificity for the desorbed metal ion, and these polymers selectively rebind the desorbed metal ion from a mixture of metal ions. For this, polyacrylamide with 8 mol % divinylbenzene (DVB) and N,N'-methylene-bisacrylamide (NNMBA) crosslinking were prepared by solution polymerization. Diethylenetriamino functions were incorporated into the polymers by polymer analogous reactions. The complexing ability of the amino polymers were investigated toward various transition metal ions like Co(II), Ni(II), Cu(II), and Zn(II). Polymeric ligand and metal complexes were characterized by various spectral methods. The removal of the metal ion from the polymer matrix resulted in a memory for the desorbed metal ion. On rebinding, these polymers specifically rebind the desorbed metal ion and from a mixture of metal ions, it showed selectivity to the desorbed metal ion. Thus, the Cu(II) desorbed polymer specifically and selectively rebind Cu(II) ion from a mixture of Cu(II) and other metal ion. This selectivity is higher in the rigid DVB-crosslinked system, resulting from the high rigidity of the crosslinked matrix compared to the semirigid NNMBA-crosslinked system. (C) 2008 Wiley Periodicals, Inc.