Hierarchical self-assembly of polydisperse colloidal bananas into a two-dimensional vortex phase

Self-assembly of microscopic building blocks into highly ordered and functional structures is ubiquitous in nature and found at all length scales. Hierarchical structures formed by colloidal building blocks are typically assembled from monodisperse particles interacting via engineered directional interactions. Here, we show that polydisperse colloidal bananas self-assemble into a complex and hierarchical quasi-two-dimensional structure, called the vortex phase, only due to excluded volume interactions and polydispersity in the particle curvature. Using confocal microscopy, we uncover the remarkable formation mechanism of the vortex phase and characterize its exotic structure and dynamics at the single-particle level. These results demonstrate that hierarchical self-assembly of complex materials can be solely driven by entropy and shape polydispersity of the constituting particles.

Automated summary

Research has found that polydisperse colloidal bananas can self-assemble into a complex and hierarchical structure, called the vortex phase, solely due to excluded volume interactions and polydispersity in particle curvature. The formation mechanism of the vortex phase and its exotic structure and dynamics have been uncovered and characterized at the single-particle level using confocal microscopy. These results demonstrate that hierarchical self-assembly of complex materials can be driven by entropy and shape polydispersity of the constituting particles.