Operating Condition and Membrane Thickness of Microcapsules Generated by Complex Coacervation Method

Abstract

Microencapsulation of glass beads with a narrow size distribution was carried out by complex coacervation of gelatin and acacia. The coacervation process was observed in detail and the effects of agitation strength, cooling rate, addition time of core material, addition plans of acetic acid and distilled water, and heating rate in the hardening process on membrane thickness of the microcapsules were investigated systematically. The membrane thickness of the microcapsules increased under the operating conditions where low cooling rate and relatively strong agitation were utilized, and pH was changed moderately by discrete addition of acetic acid or distilled water over a certain time interval. It became clear that strict control of operating conditions at 19°C in the cooling process where the viscosity of the coacervate suddenly increases is remarkably important for the control of membrane thickness.