Membrane engineering of colloidosome microcompartments using partially hydrophobic mesoporous silica nanoparticles

Covalent coupling of hexadecyltrimethoxysilane to the surface of as-synthesized silica-surfactant mesostructured nanoparticles followed by chemical removal of the surfactant template is used to prepare partially hydrophobic mesoporous silica nanoparticles with uniform shape and size comprising both hydroxyl and hexadecyl surface moieties. The mesoporous nanoparticles are used as surface-active building blocks for the preparation of water-in-oil Pickering emulsion droplets consisting of shell-like inorganic microarchitectures (colloidosomes) that exhibit a high adsorption capacity for water/oil-soluble dyes and support interfacial catalytic activity. The colloidosomes can be transferred to water by cross-linking to produce microcapsules delineated by a continuous inorganic nanoparticle-based membrane showing type IV mesoporosity and a high adsorption capacity for gaseous N₂. The design and construction of colloidosomes based on mesoporous nanoparticle building blocks should offer a general route to inorganic microcompartments with tunable porosities, host-guest membrane chemistry, and surface reactivity.