A method for separating particles in liquid by exploiting the competition between acoustic radiation force and electrostatic force has been investigated. To elucidate the size and charge dependence of the shift of the particles away from the sound pressure node, the effective charges of polystyrene spheres and alumina particles, which have opposite signs of electric charge on the surface, were measured for particles of various diameters. The shift of the particles from the pressure node due to the electrostatic force was also measured. Polystyrene spheres smaller than 10μm in diameter showed same mobility in a 1Hz, 13.4Vpp/mm alternating electric field, which indicates that the effective charge of the particle is directly proportional to the radius of the particle. Using 500kHz ultrasound and a 0.5V/mm electric field, 7μm polystyrene spheres and 10 μm alumina particles were shifted in opposite directions, according to the sign of the effective charge on the particles.
|ジャーナル||Japanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers|
|出版ステータス||Published - 1996 12 1|
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