Fabrication of hollow polymer particles using emulsions of hydrocarbon oil/fluorocarbon oil/aqueous surfactant solution

We have examined the influence of sodium dodecylsulfate (SDS) on the formation of emulsions consisting of hydrocarbon oil/fluorocarbon oil/water and the fabrication of hollow polymer particles by simple radical polymerization using these emulsions. Emulsions consisting of ternary mixtures of styrene/perfluoro-n-octane (PFO)/aqueous SDS solution are prepared at 80 degrees C. Light and fluorescence microscopy observations indicate that the ternary mixtures are O/W (oil-in-water)-type emulsions. It is found that PFO droplets are present on the surface of styrene droplets. In other words, the oil droplets show Janus-type morphologies consisting of styrene and PFO. When the ternary mixtures of styrene/PFO/aqueous SDS solution are polymerized at 80 degrees C, subsequent SEM observations indicate that the hollow cup-type polystyrene particles with a single hole on the surface are fabricated by polymerization using the Janus emulsion droplets. The hole size decreases with increasing polymerization time. These results suggest that morphologies of emulsions of ternary mixtures of hydrocarbon oil, fluorocarbon oil, and aqueous SDS solution contribute to those of polymer particles fabricated by the radical polymerization. Submicron capsules containing aqueous solutions of a fluorescent material are prepared through the hollow cup-type particles. (C) 2017 Elsevier B.V. All rights reserved.