Controlling pattern formation in nanoparticle assemblies via directed solvent dewetting

Phys Rev Lett. 2007 Sep 14;99(11):116103. doi: 10.1103/PhysRevLett.99.116103. Epub 2007 Sep 14.

Abstract

We have achieved highly localized control of pattern formation in two-dimensional nanoparticle assemblies by direct modification of solvent dewetting dynamics. A striking dependence of nanoparticle organization on the size of atomic force microscope-generated surface heterogeneities is observed and reproduced in numerical simulations. Nanoscale features induce a rupture of the solvent-nanoparticle film, causing the local flow of solvent to carry nanoparticles into confinement. Microscale heterogeneities instead slow the evaporation of the solvent, producing a remarkably abrupt interface between different nanoparticle patterns.