Wet Classification of a Submicron Silica Particle Using Counter-Electrophoresis and Orthogonal-Electrophoresis Method

Abstract

We have investigated the wet classification of a submicron silica particle using the counter-and orthogonalelectrophoresis method. The counter-electrophoresis method is a classification technique to move particles in the opposite direction with respect to their gravitational settling direction using electrophoresis. In contrast, the orthogonalelectrophoresis method is a technique to move particles using electrophoresis in the orthogonal direction with respect to the flow direction of the slurry. In order to examine the effectiveness of these two methods, two types of slurry were prepared: an ultrasonicated silica slurry with a constant electrophoretic mobility regardless of the particle diameter and a bead-milled silica slurry in which the absolute value of the electrophoretic mobility increases with the increase in the particle size. The results revealed that understanding the electrophoretic characteristics of the slurry and selecting a suitable classification method are important parameters for conducting wet classification using electrophoretic phenomena.

Size and Shape Selective Classification of Nanoparticles

“…In the following, Equation ( 10) is applied for converting a number-weighted twodimensional PSD of cylinders into surface-and volume-weighted ones. In this case, the property vector 𝑥𝑥 ⃗ depends on the length l and the diameter d of the cylinder according to Equation (11).…”

“…Although the separation of nanoparticles is still challenging, highly promising results for classification regarding size were obtained by using methods like nanoparticle chromatography [1][2][3][4][5][6][7][8], size-selective precipitation of semiconductor quantum dots [9,10], electrophoresis [11][12][13][14] and field flow fractionation [15][16][17][18][19][20][21][22]. In particular, chromatographic methods for the classification of nanoparticles are promising because of their high efficiency and good scalability.…”