NANOCLUSTER SUPERLATTICES GROWN AT SOLUTION SURFACES

摘要

Gold (Au)nanocrystals with hydrophilic surfactant modified surfaces were assembled into three-dimensional (3D) lattice arrangements at an air/aqueous suspension interface. The electrolyte concentration and the temperature controlled the assembly rate of the nanoclusters. Under optimum conditions, micrometer-sized faceted structures were grown at the suspension surface. TEM observations show that each nanocluster assembly formed a single crystal arrangement with a hexagonal close-packed (HCP) structure where a = 5.2 nm. As the temperature rises, the attractive interactions between the nanoclusters increased, which indicates that the driving force of the assembly is due to the hydrophobic effect. The hydrophobic effect is a result of the hydrophilicity-hydrophobicity conversion as the pH decreases.