Nanospiral Formation by Droplet Drying: One Molecule at a Time
Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, Michigan 48202, USA
Nanoscale Res Lett 2011, 6:49 doi:10.1007/s11671-010-9793-9Published: 30 September 2010
We have created nanospirals by self-assembly during droplet evaporation. The nanospirals, 60–70 nm in diameter, formed when solvent mixtures of methanol and m-cresol were used. In contrast, spin coating using only methanol as the solvent produced epitaxial films of stripe nanopatterns and using only m-cresol disordered structure. Due to the disparity in vapor pressure between the two solvents, droplets of m-cresol solution remaining on the substrate serve as templates for the self-assembly of carboxylic acid molecules, which in turn allows the visualization of solution droplet evaporation one molecule at a time.