Synthesis and assembly of gold and iron oxide particles within an emulsion droplet; facile production of Core@Shell particles

Here we report a method for synthesising and assembling nanomaterials at the liquid-liquid interface of an emulsion droplet, resulting in a simple strategy for producing hollow Au shells, or Fe3O4@Au core@shell particles. Mercaptododecanoic acid stabilised Au nanoparticles were added to the aqueous continuous phase, in order to stabilise hexane emulsion droplets formed within a microfluidic chip. The diameters of Au Pickering emulsions could be controlled by varying the flowrates, this produce hollowparticles. The addition of a second nanoparticle, Fe3O4 (average diameter of 12 nm), into the organic phase produced core@shell particles. The diameter of the resultant material was determined by the concentration of the Fe3O4. This report is the first to demonstrate Pickering emulsions within a microfluidics chip for the production of Fe3O4@Au particles, and it is believed that this could be a versatile platform for the large scale production of core@shell particles.