Photochemical rupture of microcapsules: A model system

Abstract

Abstract Polyamide microcapsules containing solutions of azo‐bis‐isobutyronitrile (AIBN) were prepared and characterized as regards diameter and wall thickness. Under UV irradiation the AIBN eliminates nitrogen, and this, under suitable conditions, leads to rupture of the capsules. The influence of capsular diameter and wall thickness of the crosslinking agent silane, of AIBN concentration, and of light intensity on the photoelimination and rupture were studied by determining rates of nitrogen release and by microscopic examination. The results are interpreted in terms of release of nitrogen in the core followed by diffusion of nitrogen or of core solution through the walls, or rupture of the microcapsules. The application to controlled photochemical release of contents is considered.