No abstract

No abstract

No abstract

This work describes initial efforts to incorporate affinity ligands within an environmentally responsive hydrogel. Metal affinity ligands were chosen as model affinity groups and thermally responsive N-isopropyl acrylamide/acrylamide copolymers were used as the base hydrogels. The À ÀNH 2 group of the acrylamide serves as a reactive group for functionalization with metal affinity ligands. The gels were synthesized by free radical polymerization and Cu 2þ was bound to the gel via 1,4-butanediol diglycidyl ether (BDE) as a linker and iminodiacetic acid (IDA) as a chelating ligand. The base acrylamide gels were also functionalized with metal affinity ligands to allow for comparison with thermally responsive affinity gels. The results show the effectiveness of this technique for both these types of gels, and an improved method to immobilize metal affinity groups on to thermally sensitive N-isopropyl acrylamide gels was also developed. It was seen that the yields for the reaction with BDE decreased with increased reaction time in both kinds of gels, whereas reaction with IDA showed a decrease in yields with increase in temperature for N-isoporpyl acrylamide gels and increase in yields for acrylamide gels. Further techniques were developed to overcome diffusional resistances and stresses in the thermally responsive N-isopropyl acrylamide gels so as to improve the distribution of Cu 2þ ions.

No abstract