Environmental Engineering Reference
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structures, where few experimental studies report how such metallodielectric JP
assemble respond to external AC fields under DEP [
31
]. The metallodielectric
particles assemble into new types of chain structures, where the metallized halves
of neighboring particles align into lanes along the direction of the electric field,
while the dielectric halves face in alternating direction. These particles could form
clusters rather than strings, the staggered chains may also assemble in various
orientations to form different types of two-dimensional metallodielectric crystals.
The JP could display electrohydrodynamic mobility in the direction perpendicular
to the electric field, form crystals of unique symmetries by confining staggered
chains of Janus particles in a small area, or form more complex three-dimensional
(3D) bundle structures. These structures disassembled once the electric field turns
off, proving the reversibility of this process. The assembly of Janus metallodi-
electric particles may find applications in liquid-borne microcircuits and materials
with directional electric and heat transfer The metal-coated hemispheres of the
particles have a main role in the formation of different structures and in the
electrohydrodynamic mobility of the particles once the electric field intensity
within the experimental cell becomes strong enough to overcome Brownian
motion. The knowledge of Janus particles can be applied to other types of aniso-
tropic particles, which may form different types of novel structures and potentially
lead to the fabrication of new materials [
27
].
Another significant application of DEP is for sorting carbon nanotubes [
6
,
32
],
which is an essential step in the fabrication of carbon-nanotube based sensors,
because different nanotube types have different dielectric properties and dimen-
sions. DEP is also used for assembling carbon nanotube networks on electrodes.
This will enable the construction of novel sensors based on carbon nanotube
response properties. Sensors for temperature and fluid flow have also been
manufactured using DEP to deposit carbon nanotubes to electrodes [
33
,
34
].
The aim of the present study is to analyze dielectrophoresis, both theoretically
and numerically, in order to reveal its potential for novel applications in the field of
the manipulation of nanoparticles, focusing on the enhancing of the performance of
filtering devices and the reduction of nanoparticles emissions in the air through the
optimization of the residual gas filtering conditions. After reviewing the basic
equations used for modeling the dielectrophoretic process, this paper presents
some aspects regarding the numerical investigation of the behavior of a suspension
of submicron particles under the action of DEP force in a system consisting of a
micro-channel controlled with an interdigitated electrode array. In particular, we
want to identify a suitable way to predict accurately the particle entrapment by
using numerical solutions of the DEP-flow equations for the fluid and find the
optimal values of the control parameters for separation process of nanoparticles
from flue gas, in order to be useful in designing of appropriate microfluidic devices.
