8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

Wed 711:10-14:00P5.59Key role of hydrodynamic interactions in colloidalgelationAkira Furukawa 1 and Hajime Tanaka 11 Institute of Industrial Science, The University of Tokyo, Komaba 4-6-1, Meguro-ku,153-8505, Tokyo, JapanColloidal gelation is caused by the formation of a percolated network of colloidal particles suspendedin a liquid. Thus far the major transport process leading to gelation has been believed tobe the Brownian diffusion of particles. Contrary to this common belief, we reveal by numericalsimulations that many-body hydrodynamic interactions between colloidal particles also play an essentialrole in gelation: They significantly promote gelation, or lower the colloid volume fractionthreshold for percolation, as compared to their absence. We find that the incompressible natureof a liquid component and the resulting self-organization of hydrodynamic flow with a transverse(rotational) character are responsible for this enhancement of network-forming ability.59