New route to smart core-shell polymeric microgels: Synthesis and properties

A new method has been developed to prepare smart polymeric microgels that consist of well-defined temperature-sensitive cores with pH-sensitive shells. The microgels were obtained directly from aqueous graft copolymerizations of N-isopropylacrylamide and N,N-methylenebisacrylamide from water-soluble polymers containing amino groups such as poly(ethyleneimine) and chitosan. The gel diameters ranged from 300 to 400 nm. The unique core-shell nanostructures, which had narrow size distributions, exhibited tuneable responses to pH and temperature.