A spontaneous interfacial process to produce silica Janus nanosheets as perfect emulsifiers in pickering emulsions

Abstract

In this study, Janus nanosheets are synthesized using a spontaneous process at the oil/water interface based on the corporation of (3-Aminopropyl) triethoxysilane and tetraethyl orthosilicate molecules in the formation reaction of plate shape silica nanoparticles. The presence of acidic/alkali catalyst in the water phase increases the reaction rate at the proximity of the interface. Cooling down the system after a specific time causes the melted paraffin (oil phase) to solidify which completely stops the reaction and entraps the formed nanosheets at the interface. Considering the enrichment of the oil and water phases with the reactants and catalyst, respectively, it is possible to reuse them multiple times after harvesting the formed silica Janus nanosheets. The amine groups at one side and the ethoxy groups on the other side of the silica Janus nanosheets help them to serve perfectly as solid emulsifiers in Pickering emulsions.