Issue EPL Volume 78, Number 4, May 2007 Article Number 48004 Number of page(s) 5 Section Interdisciplinary Physics and Related Areas of Science and Technology DOI 10.1209/0295-5075/78/48004 Published online 07 May 2007

EPL, 78 (2007) 48004
DOI: 10.1209/0295-5075/78/48004

Enhanced dielectrophoresis of nanocolloids by dimer formation

E. Salonen¹, E. Terama¹, I. Vattulainen^{1, 2, 3} and M. Karttunen<sup>4

1</sup>  Laboratory of Physics and Helsinki Institute of Physics, Helsinki University of Technology - Espoo, Finland
²  Memphys-Center for Biomembrane Physics, University of Southern Denmark - Odense, Denmark
³  Institute of Physics, Tampere University of Technology - Tampere, Finland
⁴  Department of Applied Mathematics, The University of Western Ontario - London, Ontario, Canada

emppu.salonen@hut.fi
emt@fyslab.hut.fi
vattulai@csc.fi
mkarttu@uwo.ca

received 17 January 2007; accepted in final form 10 April 2007; published May 2007
published online 7 May 2007

Abstract
We investigate the dielectrophoretic motion of charge-neutral, polarizable nanocolloids through molecular dynamics simulations. Comparison to analytical results derived for continuum systems shows that the discrete charge distributions on the nanocolloids have a significant impact on their coupling to the external field. Aggregation of nanocolloids leads to enhanced dielectrophoretic transport, provided that increase in the dipole moment upon aggregation can overcome the related increase in friction. The dimer orientation and the exact structure of the nanocolloid charge distribution are shown to be important in the enhanced transport.

PACS
82.70.Dd - Colloids.
47.57.jd - Electrokinetic effects.
82.20.Wt - Computational modeling; simulation.

© Europhysics Letters Association 2007

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