Colloids at interfaces: Pinned down

In 1903 Walter Ramsden found that an air bubble placed in a liquid suspension of microscopic particles can be seen to pick up the particles and to retain them obstinately 1 Ramsden had discovered the strong affinity of colloidal particles to fluid interfaces, an affinity that a century later can be harnessed to make microstructured materials such as Pickering emulsions, colloidosomes and bijels2. The production of these materials relies not only on the particles obstinately sticking to the interface, but also on their ability to move about and self-assemble. In this regard, Maurizio Nobili and colleagues3