Encapsulation of ionic liquid BMIm[PF6] within polyurea microspheres

Abstract The encapsulation of 1-butyl-3-methylimidazolium hexafluorophosphate (BMIm[PF 6 ]) in polyurea microspheres is demonstrated. This method is based on the encapsulation of ionic liquid within a polyurea shell by emulsification and interfacial polymerization of amine and isocyanate monomers. Emulsification of BMIm[PF 6 ] was performed in water or oil, enabling formation of two different BMIm[PF 6 ] polyurea microcapsules with different chemical features. While the BMIm[PF 6 ]-in-water emulsion enables the formation of BMIm[PF 6 ] polyurea microcapsules with regular aliphatic diamines, the BMIm[PF 6 ]-in-oil emulsion requires the utilization of a specific diamine functionalized with ionic liquid groups. The microcapsules were characterized by scanning electron microscopy, thermal gravimetric analysis, infrared and solid NMR.