Dielectric response of a dilute suspension of spherical colloidal particles to an oscillating electric field

1997 ◽  
Vol 93 (17) ◽  
pp. 3145-3154 ◽  
Author(s):  
Christine S. Mangelsdorf ◽  
Lee R. White
Keyword(s):  
Electric Field ◽  
Dielectric Response ◽  
Colloidal Particles ◽  
Oscillating Electric Field ◽  
Dilute Suspension

Unsteady electrophoretic motion of a non-spherical colloidal particle in an oscillating electric field

1994 ◽  
Vol 278 ◽  
pp. 149-174 ◽  
Author(s):  
Michael Loewenberg
Keyword(s):  
Dielectric Constant ◽  
Electric Field ◽  
Colloidal Particle ◽  
Volume Fraction ◽  
Added Mass ◽  
Surface Conductivity ◽  
Spherical Particles ◽  
Oscillating Electric Field ◽  
Dilute Suspension ◽  
Spherical Colloidal Particle

The oscillatory motion of an electrically charged non-spherical colloidal particle in an oscillating electric field is investigated. The particle is immersed in an incompressible viscous fluid and assumed to have a thin electric double layer. For moderate-aspect-ration spheroids and cylinders, a simple algebraic expression is derived that accurately describes oscillatory electrophoretic particle motion in terms of the steady Stokes resistance, added mass, and Basset force. The effects of double-layer conduction and displacement currents within dielectric particles are included. The results indicate that electroacoustic measurements may be able to determine the ζ-potential, dielectric constant, surface conductivity (and microstructural information contained therein), size, density, volume fraction, and possibly shape of non-spherical particles in a dilute suspension. A simple formula is obtained for the high-frequency electrical conductivity of a dilute suspension of colloidal spheroids with arbitrary charge and dielectric constant; only the added mass and Basset force are required and the requisite parameters are given. The result is needed for electroacoustic measurements but it may also be independently useful for determining the dielectric constant, surface conductivity, volume fraction, and possibly the shape of non-spherical particles in a dilute suspension. Electroacoustic energy dissipation is described for a dilute colloidal suspension. It is shown that resistive electrical heating and viscous dissipation occur independently. Electrical and viscous dissipation coefficients that characterize the order volume fraction contributions of the suspended particles are calculated; the electrical dissipation coefficient is O(1) for all oscillation frequencies, whereas the latter vanishes at low- and high-frequencies. The fluid motion is shown to be a superposition of unsteady, viscous and potential flows past an oscillating particle with no applied electric field. The electro-osmotic flow field is insensitive to particle geometry and qualitatively different from the flow past an oscillating particle with no applied field.

scholarly journals Shape-directed dynamics of active colloids powered by induced-charge electrophoresis

2018 ◽  
Vol 115 (6) ◽  
pp. E1090-E1099 ◽  
Author(s):  
Allan M. Brooks ◽  
Syeda Sabrina ◽  
Kyle J. M. Bishop
Keyword(s):  
Electric Field ◽  
Colloidal Particles ◽  
Point Group ◽  
Three Dimensions ◽  
Rigid Particles ◽  
Complex Particle ◽  
Energy Inputs ◽  
Oscillating Electric Field ◽  
Different Shapes ◽  
Induced Charge

The symmetry and shape of colloidal particles can direct complex particle motions through fluid environments powered by simple energy inputs. The ability to rationally design or “program” the dynamics of such active colloids is an important step toward the realization of colloidal machines, in which components assemble spontaneously in space and time to perform dynamic (dissipative) functions such as actuation and transport. Here, we systematically investigate the dynamics of polarizable particles of different shapes moving in an oscillating electric field via induced-charge electrophoresis (ICEP). We consider particles from each point group in three dimensions (3D) and identify the different rotational and translational motions allowed by symmetry. We describe how the 3D shape of rigid particles can be tailored to achieve desired dynamics including oscillatory motions, helical trajectories, and complex periodic orbits. The methodology we develop is generally applicable to the design of shape-directed particle motions powered by other energy inputs.

Giant Dielectric Response with an Electric Field in Charge-Ordered La1−xCaxMnO3Compounds

2009 ◽  
Vol 92 (6) ◽  
pp. 1366-1369 ◽  
Author(s):  
Ying Hou ◽  
Yiping Yao ◽  
Genqiang Zhang ◽  
Qingxuan Yu ◽  
Xiaoguang Li
Keyword(s):  
Electric Field ◽  
Dielectric Response ◽  
Giant Dielectric

Parametric excitation in an inhomogeneous plasma

1971 ◽  
Vol 5 (1) ◽  
pp. 107-113 ◽  
Author(s):  
C. S. Chen
Keyword(s):  
Electric Field ◽  
Parametric Excitation ◽  
Growth Rates ◽  
Inhomogeneous Plasma ◽  
Electron Plasma ◽  
Transverse Waves ◽  
Circularly Polarized ◽  
Polarized Waves ◽  
Oscillating Electric Field ◽  
Unmagnetized Plasma

An infinite, inhomogeneous electron plasma driven by a spatially uniform oscillating electric field is investigated. The multi-time perturbation method is used to analyze possible parametric excitations of transverse waves and to evaluate their growth rates. It is shown that there exist subharmonic excitations of: (1) a pair of transverse waves in an unmagnetized plasma and (2) a pair of one right and one left circularly polarized wave in a magnetoplasma. Additionally, parametric excitation of two right or two left circularly polarized waves with different frequencies can exist in a magnetoplasma. The subharmonic excitations are impossible whenever the density gradient and the applied electric field are perpendicular. However, parametric excitation is possible with all configurations.

Nonlinear Dielectric Response of Relaxor PMN-PZT Ceramics under DC Electric Field

2004 ◽  
Vol 307 (1) ◽  
pp. 151-159 ◽  
Author(s):  
S. A. GRIDNEV ◽  
A. A. GLAZUNOV ◽  
A. N. TSOTSORIN
Keyword(s):  
Electric Field ◽  
Dielectric Response ◽  
Pzt Ceramics ◽  
Nonlinear Dielectric ◽  
Dc Electric Field

Oscillating Electric Field Effects on Adsorption of the Methane–Water System on Kaolinite Surface

2018 ◽  
Vol 32 (11) ◽  
pp. 11440-11451 ◽  
Author(s):  
Yudou Wang ◽  
Bo Liao ◽  
Zhaoyang Kong ◽  
Zhigang Sun ◽  
Li Qiu ◽  
...  
Keyword(s):  
Electric Field ◽  
Water System ◽  
Electric Field Effects ◽  
Field Effects ◽  
Oscillating Electric Field ◽  
Kaolinite Surface

Assembly of Colloidal Particles into Microwires Using an Alternating Electric Field

Langmuir ◽  
2005 ◽  
Vol 21 (11) ◽  
pp. 4874-4880 ◽  
Author(s):  
Simon O. Lumsdon ◽  
David M. Scott
Keyword(s):  
Electric Field ◽  
Colloidal Particles ◽  
Alternating Electric Field

scholarly journals Bidirectional rotation control of a carbon fiber in nematic liquid crystal using AC electric field

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jun-Yong Lee ◽  
Jeong-Seon Yu ◽  
Jong-Hyun Kim
Keyword(s):  
Free Energy ◽  
Liquid Crystal ◽  
Electric Field ◽  
Colloidal Particles ◽  
Colloidal System ◽  
Wide Angle ◽  
Local Minima ◽  
Free Energies ◽  
Rotation Direction ◽  
Ac Electric Field

Abstract Colloidal particles dispersed in nematic liquid crystals are aligned along the orientation that minimizes the elastic free energy. Through applying an electric field to a nematic colloidal system, the orientation of the director can change. Consequently, colloidal particles realign to minimize the total free energy, which is the sum of the elastic and electric free energies. Herein, we demonstrate that if the preferred rotation directions given by the electric and elastic free energies are different during realignment, the rotation direction of the particle can be controlled by how we apply the electric field. When the strength of the electric field gradually increases, the particles rotate in the same direction as the rotation of the director. However, when a sufficiently high electric field is suddenly applied, the particles rotate in the opposite direction. In this study, we analyzed the effect of free energy on the bidirectional rotation behavior of the particles using a theoretical model. This study provides an effective approach to control the rotational behavior of colloidal particles over a wide-angle range between two orientational local minima.

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