Synthesis and characterization of new polymeric ionic liquid microgels

A new two-step route toward the synthesis of polymeric ionic liquid microgel particles is presented. In the first step, hydrophilic microparticles were prepared by the concentrated emulsion polymerization of the ionic liquid 1-vinyl-3-ethylimidazolium bromide in the presence of small amounts of N,N-dimethylenebisacrylamide as a cross-linking agent. In the second step, the bromide anion was exchanged in water with different anions such as BF4-, CF3SO3-, (CF3SO2)(2)N-, (CF3CF2SO2)(2)N-, and dodecylbenzenesulfonate, and this resulted in the coagulation of the microparticles, which were easily recovered by filtration. The obtained polymeric ionic liquid microparticles could be swollen in a very broad range of organic solvents, including apolar organic solvents. As an application, glucose oxidase was encapsulated inside polymeric ionic liquid microparticles, which were used in an amperometric biosensor. The response of the biosensor showed excellent values that strongly depended on the nature of the polymeric ionic liquid counteranion in the order of Br- > BF4(-) > (CF3SO2)(2)N-. (c) 2006 Wiley Periodicals, Inc.