A new technique for the spontaneous growth of colloidal nanoparticle superlattices

The spontaneous growth of thin films of carboxylic acid derivatized colloid al gold particles electrostatically immobilized at the hydrosol-organic sol ution interface onto moistened hydrophilic substrates is demonstrated. Imme rsion of the substrates up to the interface of the biphasic mixture leads t o superlattice formation by an extremely fast; climbing mechanism, the proc ess apparently driven by surface tension gradients at the substrate surface (Marangoni growth). This approach shows promise for development in the dep osition of superlattice films of different surface-modified colloidal nanop articles as well as salts of fatty lipids.