Size-controlled clustering of iron oxide nanoparticles within fluorescent nanogels using LCST-driven self-assembly

Abstract

Size-controlled clustering of iron oxide nanoparticles (IONPs) within the fluorescent polymer nanogels was achieved using the lower critical solution temperature (LCST) driven self-assembly and cross-linking of grafted polymer on the IONPs. The grafted polymer was comprised of oligoethyleneglycol methacrylate (OEGMA) and a novel dichloromaleimide functional methacrylate monomer as building blocks. As a result of the temperature responsive behavior of OEGMA, polymer grafted IONPs clustered to form larger nano-sized aggregates when heated above the LCST of the polymer. When these nano-sized aggregates were cross-linked using an amine-dichloromaleimide reaction, well-defined fluorescent hybrid nanogels could be fabricated. Moreover, the size of these hybrid nanogels was effectively controlled by varying the initial concentration of the polymer grafted IONPs in water. This journal is