| 초록 |
Monodisperse latex particles are known to undergo ordering to form a colloidal crystalline phase with a hexagonal closed packing structure at low ionic strength when the repulsion between the particles is strong. Two and three-dimensional periodic structures from monodispersed colloidal particles can be easily made from natural convective drying of latex under appropriate conditions. In order to fabricate the high–quality crystals on the solid substrate, however, it is very important to understand the nature of the colloidal particles and substrate as well as nucleation mechanism of the crystal. In this study, for two- and three-dimensional particle array, the natural convective drying method was applied with hydrophobically modified glass substrate, which was prepared with (3-aminopropyl)trimethoxysilane (APTMS). We showed that the particle deformation was observed at 20oC (this temperature is far from the film formation temperature) and this significantly affected the packing density and array pattern in the two and three–dimensional arrays from highly charged poly (styrene/NaSS) particle and APTMS–modified glass substrate. As the results of the particle deformation, hyperdense (packing density ~ 0.78) hcp (or fcc) packing was obtained and the square lattice structure was removed from the particle arrays. We do expect that the square lattice formation, point defects, line defects and dislocations can be effectively eliminated with this system toward minimal defect colloid crystals. |
