(400b) Semipermeable Colloidosomes from Double Emulsions

Colloidosomes are semipermeable capsules composed of a shell of colloidal particles. Nanoparticle colloidosomes with selective permeability are generated by using water-in-oil-in-water (W/O/W) double emulsions as templates. Glass capillary microfluidic devices are used to prepare monodisperse W/O/W double emulsions with a core-shell geometry. Hydrophobic silica nanoparticles that are dispersed in the oil phase stabilize the double emulsions, and subsequently make up the shell of the colloidosomes upon removal of the organic solvent in the shell. Morphology of the colloidosomes can also be controlled by varying the number of internal droplets resulting in non-spherical colloidosomes. The nanoparticle colloidosomes have selective permeability to molecules with different molecular weights. Our approach provides a general and robust means to fabricate colloidosomes with different compositions.