The mechanism of 60Co γ-ray radiation induced interfacial redox reaction in inverse emulsion and its application in the synthesis of polymer microcapsules

The motivation of this work is to explore the formation mechanism of polymer microcapsules via γ-ray radiation in W/O inverse emulsion system. Utilizing the strong reducing radical (eaq−, hydrated electron) and oxidant radical (OH, hydroxyl radical) produced in the aqueous phase by the 60Co γ-ray radiation, two interfacial redox initiation systems were proposed and applied to the preparation of polymer microcapsules. In this work, BPO (benzoyl peroxide)-eaq− and DMA (N,N-dimethyl aniline)-OH were used to control the polymerization position at the water-oil interface. Finally, polystyrene (PS) microcapsules were synthesized successfully. From the kinetic curves of monomer conversion, the mechanism of radiation induced interfacial reaction was determined and this method can be extended to synthesize polymer capsules and composite spheres.