Stabilizing and structuring oil–oil interfaces by molecular brush surfactants

Oil-in-oil emulsions provide a unique platform for numerous applications not compatible with water or aqueous systems. However, the limited types and complicated synthesis process of surfactants are problematic. Here, we put forward simple, yet powerful strategy to stabilize oil–oil interface, then prepare oil-in-oil emulsions, by using co-assembly polar molecular brushes nonpolar oligomeric ligands at DMF–octane interface. Molecular brush (MBSs) form assemble in situ minimizing interfacial energy producing robust film. We find that binding MBS interface is sufficiently high, leading construction structured liquids jamming MBSs. Using MBSs as emulsifiers, different including DMF-in-octane, octane-in-DMF, high internal phase can be easily prepared, showing promising microreactor systems advanced composite materials.