Self-Emulsion Polymerization of Amphiphilic Monomers—A Green Route to Synthesis of Polymeric Nanoscaffolds

Abstract

Self-emulsion polymerization (SEP), a green route developed by us for the polymerization of amphiphilic monomers, does not require any emulsifier or an organic solvent except that the water-soluble initiators such as 2,2 '-azobis[2-(2-imidazolin-2-yl)propane]dihydrochloride (VA-044) and potassium persulfate (KPS) are only used. We report here the polymer nanoscaffolds from a number of amphiphilic monomers, which can be used for in situ encapsulation of a variety of nanoparticles. As a demonstration of the efficacy of these nanoscaffolds, the synthesis of a biocompatible hybrid nanoparticle (nanohybrid), prepared by encapsulating Fe3O4 magnetic nanoparticle (Fe3O4 MNPs) in poly(2-hydroxyethyl methacrylate) in water, for MRI application is presented. The nanohybrid prepared following the SEP in the form of an emulsion does not involve the use of any stabilizing agent, crosslinker, polymeric emulsifier, or surfactant. This water-soluble, spherical, and stable nanohybrid containing Fe3O4 MNPs of average size 10 +/- 2 nm has a zeta potential value of -41.89 mV under physiological conditions. Magnetic measurement confirmed that the nanohybrid shows typical magnetic behavior having a saturation magnetization (Ms) value of 32.3 emu/g and a transverse relaxivity (r2) value of 29.97 mM(-1) s(-1), which signifies that it can be used as a T2 contrast agent in MRI. (c) 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019