화학공학소재연구정보센터
Langmuir, Vol.21, No.13, 5667-5671, 2005
Fabrication of gradient colloidal topography
A rather simple but yet effective way to self-assemble polystyrene (PS) beads in gradient colloidal crystal topography is proposed. The PS bead concentration, solvent, and substrate have a big effect on the colloidal crystal topography. Whether the gradient-shaped crystals can form or not depends on the Bond number [Bo; the ratio of gravitational potential energy (G) to adhesive energy (E-a), or gravitational to capillary forces]. When Bo < 1, that is, the capillary force dominates over the gravitational force, the liquid meniscus is stable. The gradient-shaped crystals can form. Otherwise, PS beads form a uniform multilayer structure.