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 types of microcapsules with the shell thickness from 1.0 to 5.0μm were
able to be prepared under all the experimental conditions adopted here.
Cite this paper
Y. Yokoyama, K. Fuchigami, Y. Taguchi and M. Tanaka, "Preparation of Microcapsules with Liquid Droplet Coalescence Method Followed by Phase Separation," Journal of Encapsulation and Adsorption Sciences, Vol. 3 No. 3, 2013, pp. 93-97. doi: 10.4236/jeas.2013.33011.
 T. Kondo, “Saishin Makurokapseruka Gijutsu (Microencapsulation Technique) (in Japanese),” ETS, Tokyo, 1967.
 T. Tanaka, “Key Point of Preparation of Nano/Microcapsules,” Techno System Publishing Co. Ltd., Tokyo, 2008.
 M. Takahashi, Y. Taguchi and M. Tanaka, “Microencapsulation of Hydrophilic Solid Powder as a Fire Retardant by the Method of in Situ Gelation in Droplets Using a Non-Aqueous Solvent as the Continuous Phase,” Polymers & Polymer Composites, Vol. 17, No. 2, 2009, pp. 83-90.
 M. Takahashi, Y. Taguchi and M. Tanaka, “Microencapsulation of Hydrophilic Solid Powder as Fire Retardant Agent with Epoxy Resin by Droplet Coalescence Method,” Journal of Applied Polymer Science, Vol. 110, No. 3, 2008, pp. 1671-1676. doi:10.1002/app.28211
 M. Takahashi, Y. Taguchi and M. Tanaka, “Microencapsuration of Hydrophilic Solid Powder as a Flame Retardant with Epoxy Resin by Using Interfacial Reaction Method,” Polymers for Advanced Technologies, Vol. 21, No. 3, 2010, pp. 224-228.
 A. Branko, S. Urska and K. Matjaz, “Differential Scanning Calorimetric Examination of Melamine-Formalde- hyde Microcapsules Containing Decane,” Journal of Applied Polymer Science, Vol. 119, 2011, pp. 3687-3695.
 X.-X. Zhang and X.-M. Tao, “Structure and Thermal Stability of Microencapsulated Phase-Change Materials,” Colloid & Polymer Science, Vol. 282, 2004, pp. 330-336.
 T. Takahashi, Y. Taguchi and M. Tanaka, “Preparation of Polyurea Microcapsules Containing Pyrethroid Insecticide with Hexamethylene Diisocyanate Isocyanurate,” Journal of Applied Polymer Science, Vol. 107, No. 3, 2008, pp. 2000-2006. doi:10.1002/app.27238
 E. O’shima and M. Tanaka, “Coalescence and Breakup of Droplets in Suspension Polymerization,” Kagaku Kogaku Ronbunshu, Vol. 8, No. 1, 1982, pp. 86-90.
 M. Tanaka, “Local Droplet Diameter Variation in a Stirred Tank,” The Canadian Journal of Chemical Engineering, Vol. 63, No. 5, 1985, pp. 723-727.
 K. Hosogai and M. Tanaka, “Study of Suspension Polymerization of Styrene with a Circular Loop Reactor,” Polymer Engineering and Science, Vol. 32, No. 6, 1992, pp. 431-437. doi:10.1002/pen.760320608