Preparation of Polymer Particles Containing Reduced Graphene Oxide Nanosheets Using Ionic Liquid Monomer

The preparation of polymer nanoparticles containing reduced graphene oxide nanosheets (rGO) within their interior has been conducted by radical polymerization in aqueous miniemulsion employing the nonionic surfactant Tween 80. Polymerizations were conducted using the ionic liquid monomer 1-vinyl-3-ethylimidazolium bis(trifluoromethanesulfonyl)amide ([Veim][TFSA]) as well as mixtures of this monomer with ethyl methacrylate (EMA). [Veim][TFSA] plays an important role in that it provides stabilization of rGO monomer dispersions, presumably via π–π interactions between rGO and [Veim][TFSA]. If the EMA:[Veim][TFSA] ratio is too high, rGO precipitates during preparation of the monomer phase of the miniemulsion. Interestingly, it was demonstrated that addition of a small amount of the homopolymer of [Veim][TFSA] leads to significantly improved rGO stability (more so than the effect of [Veim][TFSA] monomer), thus enabling preparation of polymer nanoparticles containing higher amounts of EMA.