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

P5.74Wed 711:10-14:00Structural changes in dipolar colloidal gels due toexternal fieldsPatrick Ilg 1 and Emanuela Del Gado 11 ETH Zurich, Institute for Polymers, HCI H529, Wolfgang-Pauli-Str. 10 8093, Zurich,SwitzerlandDipolar colloids can form a reversible but persistent network (gel) made of chain-like structures.We perform molecular dynamics simulations of charged soft dumbbells and find that, under theeffect of an external electric field, this gel displays a highly non-linear electrical susceptibility.We show that the nonlinearity is due to the field-induced switching from a network to a structureof bundling chains. Such dramatic structural transformation upon applying external fields couldallow the control of the mechanical and electrical response of these complex fluids, pointing tonew applications of dipolar colloids as smart materials. P. Ilg, E. Del Gado, Soft Matter 7 (2011)163.74