Preparation of Micron-Sized Monodisperse Poly(ionic liquid) Particles

Micron-sized monodisperse poly(ionic liquid) (PIL) particles, poly([2-(methacryloyloxy)ethyl]trimethylammonium bis(trifluoromethanesulfonyl)amide), were prepared by dispersion polymerization at 70 degrees C in methanol with poly(vinylpyrrolidone) as a stabilizer. The obtained particle size could be controlled by addition of ethanol to the methanol medium while maintaining narrow monodispersity. The PIL particles exhibit unique properties; they can be observed by scanning electron microscopy without platinum coating, which is generally used to avoid an electron charge. Moreover, the solubility of the PIL particles can be easily changed by changing the counter anion, similar to the process for ionic liquids.