Abstract
Frank Smallenburg: „Colloidal particles in external biaxial and uniaxial electric fields”
University of Utrecht, The Netherlands
Colloidal particles with a dielectric constant mismatch with the surrounding solvent in an external electric field obtain a dipole moment parallel to the field. The resulting dipolar interactions significantly affect the phase behavior of the particles, and can lead to the self-assembly of a large variety of string-like structures, depending on the shape of the particles. Additionally, if a biaxial (rotating) field is used, the particles interact via an "inverted" dipole interaction, leading to sheet-like aggregates.
We determine the phase behavior both colloidal hard spheres and charged spheres in a biaxial field, using Helmholtz free energy calculations in Monte Carlo simulations. Additionally, we examine the structures that can be formed in uniaxial fields by modifying the shape of the particles, and compare our results with preliminary experimental results.