Defined core–shell particles as the key to complex interfacial self-assembly

Abstract

Significance The spontaneous self-organization of matter is ubiquitous in nature and an attractive technological approach to create defined nanostructured materials from the bottom-up. Spherical colloidal particles are among the most widely used building blocks, but their self-assembly is limited to hexagonal symmetries as the densest sphere packing. Here, we demonstrate that this limitation in structural versatility can be overcome using soft core–shell particles self-assembling at a liquid interface. The propensity of the polymer shell to spread at such interfaces allows tailoring their interactions, which in turn affords a complex, nonintuitive phase behavior upon compression. The observed structures agree with theoretical predictions of particles interacting via two length-scale Jagla potentials, which have been predicted decades ago but remained elusive in experiments.