A Novel Thermoresponsive P(NIPAAm-Co-Calix) Hydrogel: Synthesis, Characterization and its Sorption Ability for Metal Ions

A novel supramolecular smart poly(N-isopropylacrylamide-co-tetra(5-hexenyloxy)-p- tert-butylcalix[4]arene) (P(NIPAAm-co-Calix)) hydrogel was synthesized by free radical polymerization of N-isopropylacrylamine(NIPAAm) and modified calix[4]arene. The swelling behaviours and ionic adsorption capacity were studied. It is found that the polymeric network of the P(NIPAAm-co-Calix) hydrogel is characterized by an open structure with more pores and higher swelling ratio compared to the PNIPAAm hydrogel. The adsorption abilities of heavy toxic metal ions (Ni2+, Cu2+, Pb2+, Cd2+) for P(NIPAAm-co-Calix) hydrogels and PNIPAAm hydrogel were different and depend on the temperature. This could provide a theoretical basis for the intelligent response mechanism to stimulate research of supramolecular hydrogel.