One-step preparation of hydrophilic–hydrophobic asymmetric bilayer microcapsules via photopolymerization

Abstract

Microcapsules with large cavities have been widely used as microcontainers in various fields. Their practical applications in aqueous systems often require a combination of water dispersibility, water-resistance and mechanical properties. Microcapsule architectures combining all these characteristics face challenges including delicate structure design and efficient fabrication. In this work, a novel kind of hydrophilic–hydrophobic asymmetric bilayer microcapsule was developed, which achieved a good combination of the desired features for application in aqueous systems. The bilayer microcapsules with a hydrophilic outer shell and a hydrophobic inner shell were prepared in one step by “phase separation inside an emulsion droplet” combined with photopolymerization. With this unique hydrophilic–hydrophobic asymmetric shell, the microcapsules possessed balanced dispersibility in water and water-resistance properties as well as simultaneously exhibiting outstanding mechanical properties.