Preparation of Microcapsules with Liquid Droplet Coalescence Method Followed by Phase Separation
- 1 Department of Management Information, Niigata University of Management, Niigata, Japan
- 2 Department of Research & Development, Shyofu Inc., Kyoto, Japan
- 3 Graduate School of Science and Technology, Niigata University, Niigata, Japan
- 4 Graduate School of Science and Technology, Niigata University, Niigata, Japan
Abstract
Novel preparation method of microencapsules was developed on the basis of the liquid coalescence method followed by phase separation. Oil droplets of limonene dissolving expanded polystyrene as a shell material were forced to collide and coalesce with the Isopar oil droplets of core material in the continuous wates phase. When two kinds of oil droplets are collided and coalesced with each other, expanded polystyrene dissolved in the limonene oil may be phase-separated in the oil droplets newly formed to form the microcapsule shell, because the Isopar oil was a poor solvent for expanded polystyrene but a good solvent for the limonene oil. In the experiment, the diameter (or number) of limonene oil droplets dissolving expanded polystyrene was mainly changed, because the coalescence frequency between the droplets is strongly dependent on the number of droplets. Favorable core shell type s of microcapsules with the shell thickness from 1.0 to 5.0 μm were able to be prepared under all the experimental conditions adopted here.
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