Production and applications of spore microcapsules

This thesis involves the preparation of exine shells derived from spores. The exines shells provide a ready source of microcapsules of uniform shape and monodispersed size in the region of 4 to 50 mm. The objective of the research was to fill the exine shells with various functional materials, and to examine qualitatively their bulk properties. Thus, the main production techniques and applications of sporopollenin microcapsules were extensively reviewed, with the objective of shortening the production process in order to develop commercial isolation techniques for sporopollenin exines. The conventional base and acid treatment was simplified and the microcapsules produced by this method were investigated detailed in order to evaluate the yield and quality of the exines. In order to demonstrate the utility of this procedure attempts were made to further simplify by shorter reaction time and limit chemicals applied. The overall result achieved was higher quality and useable exines, produced in a shorter time under less extreme conditions. The filling of exine microcapsules was studies for a range of materials including dyes and magnetic particles. It was found that, contrary to published data, it was possible to efficiently fill the microcapsules with an absorbate using a large volume of solvent. Dyes that were encapsulated enabled the demonstration of colour change through changes in pH and also temperature. Multicomponents system were also achieved which allowed the demonstration of multifunctionality such as colour and magnetic properties. The use of microcapsules in a chromatography or capture/release vehicle was also demonstrated.