A Facile and Straightforward Strategy for the Production of Functional Polystyrene Microspheres With Well‐Defined Size and Controllable Morphology

ABSTRACT Functional polystyrene (PS) microspheres with unique size and high monodispersity play an important role in biomedical and organic synthesis. However, developing a facile strategy to prepare PS microspheres with predictable size and excellent stability remains challenging. In this study, a facile strategy is developed to prepare PS microspheres, in which sufficient sulfate radicals could be produced to initiate polymerization even without inert gas purging. 0.03 to 3 μm PS microspheres with coefficients of variation (CV) values less than 5% are prepared using optimized dispersion polymerization and emulsion polymerization. The effects of reaction conditions on the size and morphology of microspheres are studied systematically. Emulsion polymerization is utilized to prepare microsphere size less than 600 nm, and then the microspheres with size of 30 to 300 nm are fabricated by varying the copolymerization monomer concentration. Additionally, the reaction is scaled up 400 times (yield: 85%) in a 20 L reactor to further verify the large‐scale production ability of PS microspheres (CV ≤ 2%). To broaden the functionality of microspheres, microspheres with variable fluorescence intensity are prepared. The results not only provide a facile strategy for the production of narrow size distribution and high‐yield PS microspheres but also expand industrialization and downstream applications.