Fig. 1.
Schematic representation of the microencapsulation technique. First, an aqueous solution of GSE (Wi) is emulsified in an oil solution (O), consisting of PLA and Span 85 surfactant dissolved in DCM. The Wi/O emulsion solution is then further emulsified in an aqueous PVA surfactant solution (Wo) to form a Wi/O/Wo double emulsion. Upon the formation of a stable double emulsion, it is continuously agitated until DCM evaporates from the middle oil layer and a solid polymer shell wall is formed around the aqueous core. Finally, microcapsules are washed and dried to remove any residual surfactant and water from the capsules.