Résumé
The evaporation of single droplets of colloidal tobacco mosaic virus (TMV) nanopartides on a superhydrophobic surface with a hexagonal pillar-pattern results in the formation of coffee-ring type residues. We imaged surface features by optical, scanning electron, and atomic force microscopies. Bulk features were probed by raster-scan X-ray nanodiffraction. At similar to 100 pg/mu L nanoparticle concentration, the rim of the residue connects to neighboring pillars via fibrous extensions containing flow-aligned crystalline domains. At similar to 1 pg/mu L nanoparticle concentration, nanofilainents of >= 80 nm diameter and similar to 20 mu m length are formed, extending normal to the residue-rim across a range of pillars. X-ray scattering is dominated by the nanofilament form-factor but some evidence for crystallinity has been obtained. The observation of sheets composed of stacks of self-assembled nanopartides deposited on pillars suggests that the nanofilaments are drawn from a structured droplet interface.