Perspectives of aerosol-photopolymerization: Nanoscale polymer particles

Photoinitiated polymerization is employed to produce submicron polymer particles in aerosols. By ultraviolet (UV) irradiation of the aerosol monomer solution droplets, produced with the help of an atomizer, polymerization is initiated by free radical generation. The aerosol process allows the production of surfactant-free polymer particles without any solvent required, while photochemistry results in instantaneous formation of free radicals by cleavage of excited photoinitiator molecules. Furthermore, the initiation can take place independent of temperature, which provides polymerization at ambient temperature. A continuous experimental setup with a flow-through photoreactor is developed, which is characterized by a sub-minute aerosol residence time. The experiments reveal that spherical nanopolymers can be formed as 1-to-1 copy from the monomer droplets.