The effect of microcapsule size on the oxidative decomposition of core material.

The factors that affect the size of microcapsules and the oxidation of their benzaldehyde core have been examined. The pH of the preparation changed the overall size of the microcapsules which reached a maximum diameter at pH 4.1. The size of the core droplets also varied with the preparative pH and their oxidation rate depended on the bulk droplet size rather than their surface area. A rapid oxidation of benzaldehyde associated with the microcapsule wall resulted in a preliminary peak in the oxidation curve. Explanations for these phenomena are discussed.