Polymeric Nanoreactors for Hydrophilic Reagents Synthesized by Interfacial Polycondensation on Miniemulsion Droplets

We describe a versatile method to obtain functional hollow nanoreactors with a hydrophilic liquid core. The synthesis of hollow polyurea, polythiourea, and polyurethane nanocapsules was performed by interfacial polycondensation or cross-linking reactions in inverse miniemulsion. The miniemulsions were built upon emulsification of a solution of amines or alcohols in a polar solvent with cyclohexane as the nonpolar continuous phase. The addition of suitable hydrophobic diisocyanate or diisothiocyanate monomers to the continuous phase allows the polycondensation or the cross-linking reactions to occur at the interface of the droplets. The wall thickness of the capsules can be directly tuned by the quantity of the reactants. The nature of the monomers and the continuous phase are the critical factors for the formation of the hollow capsules, which is explained by the interfacial properties of the system. The resulting polymer nanocapsules could be subsequently dispersed in water. The capsules were found to be...