Influence of Gravity on Structure of Colloidal Crystal Using Simulated Microgravity

Liquid mixtures of water and deuterium oxide as the liquid phase, were used to match the density of charged colloidal particles. Kossel diffraction method was used to detect the crystal structures. The experiments under the density-matched (g=0) and unmatched (g=1) conditions are compared to examine the influence of gravity on the crystal structures formed by self-assembly of 110 nm (in diameter) polystyrene microspheres. The result shows that the gravity tends to make the lattice constants of colloidal crystals smaller at lower positions,which indicates that the effect of gravity should be taken into account in the study of thecolloidal crystals.