Andre Utgenannt in the Keddie Lab found that he could make some beautiful nanostructures simply by mixing Au nanoparticles (10 nm in diameter) in water with colloidal polymer particles (about 350 nm in diameter). The nanoparticles arranged themselves around the larger polymer particles to create ring-like structures. The periodicity resulted in photonic properties, and the Au nanoparticles display plasmonic properties. So, the materials exhibited two types of optical effects. You can read more in our open access publication in ACS Nano.
If Andre heated the nanostructures to just the right temperature, the Au nanoparticles sintered into a continuous phase. If he heated to a too high temperature, he decomposed the polymer and the structure collapsed. After the Au nanoparticles were sintered, he dissolved the polymer phase in an organic solvent. A whole “zoo” of Au nanostructures was left behind: rings, dots, and even some ribbons. You can see the menagerie in the mini-gallery here.