Wednesday, 27 June 2007 - 10:00 AM
Pencader 116
339

Dynamics and Collapses of Two-Dimensional Colloidal Lattices

Sowmitri Tarimala, Chihyuan Wu, and Lenore L. Dai. Texas Tech University, Lubbock, TX

One interesting aspect of colloidal particles is the formation of colloidal crystals at the two-dimensional and three-dimensional level. Here we report the dynamics and collapses of colloidal lattices at liquid-liquid interfaces using Pickering emulsions as an experimental template. The colloidal particles oscillate around their equilibrium positions. The short-time diffusion constant of single particles increases with increasing the lattice spacing; the oil phase viscosity only has an effect on diffusion at large inter-particle distances. Strikingly, we observe that the equilibrium structure can be disturbed when increasing the output laser intensity in a confocal laser scanning microscope which leads to the collapse of colloidal lattices under small radiation pressure forces.