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Published on: September 7, 2018
Band formation in mixtures of oppositely charged colloids driven by an ac electric field
Teun Vissers1, Alfons van Blaaderen, Arnout Imhof
1Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University, Utrecht, The Netherlands. t.vissers@uu.nl
Abstract:
We present experiments on pattern formation in a Brownian system of oppositely charged colloids driven by an ac electric field. Using confocal laser scanning microscopy we observe complete segregation of the two particle species into bands perpendicular to a field of sufficient strength when the frequency is in a well-defined range. Because of its Brownian nature the system spontaneously returns to the equilibrium mixture after the field is turned off. We show that band formation is linked to the time scale associated with collisions between particles moving in opposite directions.
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