Polyhedral-oligosilsesquioxane containing poly(methyl methacrylate) perylenebisimide microspheres with high solid state emission

Abstract

A series of novel fluorescent poly(methyl methacrylate) microbeads with narrow size distribution and intense solid state emission were designed and prepared by dispersion polymerization. The featured polyhedral oligosilsesquioxane was introduced into the perylene bisimides fluorophore system to fabricate polymeric microspheres. With poly (12-hydroxystearic acid) chains grafted to poly(methyl methacrylate) backbone as stabilizer, the obtained microspheres were narrow distributed as well as easily dispersed which are shown in the dynamic light scattering and scanning electron microscope measurement. Fluorescence microscope images of petroleum-ether dispersion of the sample exhibited strong orange emission with stability against photobleaching. More importantly, due to the steric hindrance of bulky polyhedral oligosilsesquioxane moieties, the aggregation-induced fluorescence quenching of perylene bisimides can be suppressed significantly, thus the solid-state quantum yield of the microspheres can be boosted to 68%, which is the highest record for perylene bisimide along polymeric microspheres. The excellent luminescent property, in combination with the monodisperse nature and the high stability against photobleaching of the polyhedral-oligosilsesquioxane containing microspheres, makes them a kind of promising material for fabrication of luminescent devices.