Soft nanoparticles from a University of Pennsylvania research team stick to the plane where oil and water meet, but do not stick to one another. The interface presents a potentially useful set of properties. The nanoparticles freely move past one another while being confined to the interface, effectively acting as a 2D liquid.
Gold nanoparticles were decorated with surfactant, or soap-like, ligands. The ligands have a water-loving head and an oil-loving tail, and the way they are attached to the central particle allows them to contort themselves.
The arrangement produces a “flying saucer” shape, with the ligands stretching out more at the interface than above or below. The ligand bumpers keep the particles from clumping together.
The researchers also devised ways of measuring the system's properties. Their data will better inform computer simulations and potentially lead to applications in fields like nanomanufacturing and catalysis.
Also: Learn about a Nanoparticle/Polymer Nanocomposite Bond Coating.