Two-dimensional array of nanoparticles intermitted by long chain molecules

It is an important theme in nanoscience to control the interval of the orde red array of nanoparticles through modifying the chain length of the passiv ating molecules of the nanoparticles. The theme runs through most of the ap plications of the ordered array of nanoparticles. Though the Langmuir-Blodg ett (LB) technique is one of the most important ways to prepare the two-dim ensional ordered array of nanoparticles, it has only been used in case that the passivating molecules are short enough (<C-12) When the passivating mo lecules become longer, it is difficult to obtain the ordered array of the p articles simply by compressing them on the surface of water. The present wo rk focused on the formation of the two-dimensional array of the octadecylam ine-passivated gold nanoparticles at the air/water interface. By properly m odifying the ordinary LB technique, the long-term two-dimensional ordered a rray of nanoparticles was successfully achieved. The surface pressure-area isotherms and the electron microscopy observation showed that the key to pr eparing the two-dimensional ordered arrangement of nanoparticles is to over come the interaction among the passivant shells.