Novel Capsules with High Stability and Controlled Permeability by Hierarchic Templating

Abstract

Nanoporous shell or sphere-in-sphere structures have been constructed by consecutive alternating adsorption of polyelectrolytes and SiO2 on melamine formaldehyde particles, followed by removal of the cores with HCl and SiO2 with HF. The shells have been distinguished by confocal laser scanning microscopy imaging (see picture) by partially labeling the inner shell with fluorescein (yellow emission) and the outer sphere with rhodamine B (red emission).