We study the response of single nanosized spherical colloids in electrolytesolution to an alternating electric field (AC field) by computer simulations.We use a coarse-grained mesoscopic simulation approach that accounts in fullfor hydrodynamic and electrostatic interactions as well as for thermalfluctuations. The solvent is modeled as a fluid of single Dissipative ParticleDynamics (DPD) beads, and the colloidal particle is modeled as a rigid bodymade of DPD beads. We compute the mobility and the polarizability of a singlecolloid and investigate systematically the effect of amplitude and frequency ofthe AC-fields. Even though the thickness of the Debye layer is not "thin"compared to the radius of the colloid, and the thermal fluctuations aresignificant, the results are in good agreement with the theoretical predictionof the Maxwell-Wagner-O'Konski theory, especially for uncharged colloids.
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