Soft colloids for complex interfacial assemblies

The design of complex materials and the formation of specific patterns often arise from the properties of the individual building blocks. In this respect, colloidal systems offer a unique opportunity because nowadays, they can be synthesized in the laboratory with many different shapes and features. Hence, an appropriate choice of the particle characteristics makes it possible to generate macroscopic structures with desired properties. The versatility of colloids can also be explored in two dimensions using liquid-liquid or air-liquid interfaces as privileged substrates where they can adsorb and self-assemble. Other than being innovative model systems for fundamental studies, the great interest of the scientific community is also technological and applicative since colloidal-scale surface patterns are very promising, for example, in photonics or biosensing. In a recent study published in PNAS, Menath et al. (1) combine these elements and exploit core-shell colloids, consisting of a silica core and a soft, noncross-linked polymer shell, to make an important step forward in controlling the assembly of complex structures at an interface.