Size-Sorting and Pattern Formation of Nanoparticle-Loaded Micellar Superstructures in Biconcave Thin Films.

Biconcave thin water layers represent a template to induce organization of supramolecular structures into ordered monolayers. Here we show how micelles form extensive micrometer-sized pseudo-2D superstructures that reveal size-sorting and geometric pattern formation, as shown by cryo-transmission electron microscopy (cryoTEM). Electron-rich gold particles inside the micelles facilitate direct visualization and determination of size, composition, and ordering of the micellar assemblies over multiple length scales. Some of the patterns observed show intriguing geometric patterns for superstructures, including Fibonacci-like, double-spiral domains that also appear in, for example, sunflower seed head patterns.