Morphological design of PDVB‐based particles

Polymeric microspheres with complex architectures find application as stationary phases for size exclusion separation, solid supports for surface reactions, catalysis, and delivery systems. The microparticles are commonly made from divinylbenzene by precipitation polymerization or template swelling. Upon combining both methods and applying photopolymerization, we discovered new morphological features that are not solely explicable by the individual processes. Firstly, three types of templates were synthesized by precipitation polymerization: noncrosslinked, slightly crosslinked, and slightly crosslinked with noncrosslinked polystyrene fractions. All template types were swollen with divinylbenzene, which was polymerized by photoinitiation, followed by template extraction. Changes in particle size were tracked by light microscopy, while SEM revealed submicron features like hollow cores, toluene‐insoluble walls, and surface grooves from the collapse upon drying of the toluene‐swollen corona. Our investigations indicated that the corona results from chain transfer and crosslinking of the template during photoinitiation. Higher precrosslinking of the template reduced the core cavity volume of the extracted particle, while more mobile polystyrene chains led to larger cavities. These architectures are promising model systems for fundamental studies of particle interactions, aggregation, and structure formation in the field of colloidal physics.