Analytical Sciences

Abstract − Analytical Sciences, 24(1), 121 (2008).

Microscopic Measurements of Deformation of Liquid Surfaces Induced by Localized Direct Current Electric Field
Tsuyoshi TSURUTA, Satoshi TSUKAHARA, and Terufumi FUJIWARA
Department of Chemistry, Graduate School of Science, Hiroshima University, Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan
This study presents a new microscopic method for the measurements of the deformation of liquid surfaces induced by a localized direct current (dc) electric field in a noncontact manner. Since the dielectric constant of aqueous and organic liquids is larger than that of air, the liquids tend to occupy a space with a stronger electric field. The horizontal level of transparent surfaces was measured with a constructed microscopic system that possessed a resolution of about 2 µm. When a rod electrode (2.0 mm in radius) was brought near to a liquid surface vertically within 150 - 200 µm and a dc voltage (50 - 75 V) was applied, the surface just under the electrode rose by 4 - 19 µm. The deformation of the liquid surfaces was quantitatively analyzed by using a dielectric force, surface tension, and hydrostatic pressure.