A new technique for the spontaneous growth of colloidal nanoparticle superlattices

The spontaneous growth of thin films of carboxylic acid derivatized colloidal gold particles electrostatically immobilized at the hydrosol-organic solution interface onto moistened hydrophilic substrates is demonstrated. Immersion of the substrates up to the interface of the biphasic mixture leads to superlattice formation by an extremely fast; climbing mechanism, the process apparently driven by surface tension gradients at the substrate surface (Marangoni growth). This approach shows promise for development in the deposition of superlattice films of different surface-modified colloidal nanoparticles as well as salts of fatty lipids.