All-Silica Colloidosomes with a Particle-Bilayer Shell

We report on the preparation of all-silica colloidosomes with adjustable size, shell structure, mechanical strength, and permeability. Our approach is based on the coassembly at the water/oil interface of silica nanoparticles and a silica precursor polymer—hyperbranched polyethoxysiloxane—which acts as a binder for particles as well as an additional interfacial component. Remarkably, the shell of colloidosomes can be fine-tuned from a particle monolayer up to a bilayer bound with a sandwiched thin silica film. This method presents a facile approach toward multiscale production of microcapsules which have a high potential in encapsulation technology and in smart coating formulations.