A new method of preparing monocored water-loaded micro capsules using interfacial polymer deposition process

Abstract

A new method was proposed to prepare monocored water-loaded microcapsules with diameters of 50 μm or larger by making use of the process of interfacial polymer deposition. A solution of ethylcellulose or polystyrene in dichlorometh ane was added dropwise to an O/W emulsion in which n-hexane was dispersed as fine droplets in aqueous gelatin solution. Successive evaporation of dichloro-methane at 40d`C and n-hexane at 80d`C gave monocored water-loaded ethyl cellulose or polystyrene microcapsules. Monocored water-loaded ethylcellu lose/polystyrene composite microcapsules were similarly prepared using mixed solutions of the two polymers in dichloromethane instead of ethylcellulose or polystyrene solution. When those mixed solutions which exhibit phase separation were used, the composite microcapsules obtained had a patchwork-like structure in which polystyrene-rich islands are dispersed in the ethylcellulose-rich sea.