Space-charge-perturbed electrophoresis in nonpolar colloidal dispersions

Abstract

This paper reports the observation of bipolar, space-charge-perturbed transport in colloidal dispersions using an experimental technique that time-resolves electrophoresis in nonpolar colloidal systems. Unlike existing methods for studying electrophoresis, this technique can be applied to dispersions of diverse types and concentrations over a wide range of electric fields, including the space-charge-perturbed conditions often encountered in practical applications. The phenomenon is investigated as a special case of dielectric relaxation in a leaky capacitor connected in series to a perfect one. Using the first principle charge transport theory, such dielectric relaxation, occurring under the non-Ohmic supply and space-charge-perturbed transport conditions, is shown to differ from that expected by the conventional equivalent-circuit treatment. The combined theoretical analysis and the experimental technique provides a means for independently determining the densities and mobilities of charged species in such systems. Using a liquid developer for electrography as a prototype system, results are presented that illustrate the power of the technique as a new tool to provide new insights into the generic transport and generation mechanisms of charged species in colloidal systems.

Evaluation of Electrophoretic Migration of Submicron Particles in a Microgap by Optical and Current Responses

“…11) The cell with a small gap was modeled in one-dimension, where the direction vertical to the flat electrode was expressed as the X-axis. We show the equations of the model for N types of charged particles.…”

“…nðx; tÞ is assumed to have the Gaussian distribution expressed as 11) nðx; tÞ ¼ N ð2Þ 1=2 s Et exp À 1 2…”

Synthesis of polystyrene nanoparticles with monodisperse size distribution and positive surface charge using metal stearates

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Phase- and Wall-Locked Modes Found in a Large Reversed-Field Pinch Machine, TPE-RX

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