Noniridescent colloidal nanostructures


Noniridescent properties of dried patterns of the model liquids. Photographs of deposited patterns with three different size of silica nanoparticles which are originally composed of (left column) silica + water + ethanol (solution A, B, and C) and (right column) silica + water + ethanol + PEO (solution D, E, and F) where the viewing angle is varied. The pictures are taken under ambient light. Scale bars are 2 mm.

Photonic crystal and photonics glass
Description: Nano silica particles can be packed in a crystalline or disordered structure. The reflected color depends on the particle size and the inter distance between particles. On the left hand side, we display opal materials that consist of 220 nm silica particles, which are packed in a crystalline structure.
New coating method (PRL Editors' suggestion) 
Description: A new particle coating method is introduced, inspired by a dried mark of whisky. A comparison of dried marks of an actual whisky drop (top left), a whisky drop with fluorescent particles (top right), and a model liquid with fluorescent particles (bottom).

Related publication: Kim et al. “Controlled uniform coating induced by multiple Marangoni flows and surface-adsorbable macromolecules,” accepted, PHYS REV LETT.