Self-assembled stripe patterns of CdS nanorods

Sterically stabilized CdS nanorods, 3-5 nm in diameter with aspect ratios ranging from 4 to 15, were observed to self-align into networks of stripes several micrometers long when drop-cast from dispersions at submonolayer coverage. The stripes are two to three nanorods thick with nanorods assembled side-by-side with their long axes parallel to the stripe direction. Energetic forces between nanorods, such as van der Waals and dipole-dipole attractions, favor parallel nanorod alignment; however, we propose that pattern formation is kinetically limited, or mediated, by solvent evaporation.