Hypothesis

The shape of the liquid film (SLF) between a glass slide and an oil droplet immersed in an aqueous solution is influenced by the direct current (DC) electric field. The liquid film, consisting of the central film region and the meniscus film region, is formed between a floating oil droplet and a glass slide overhead.

Experiments

The SLF was experimentally studied in aqueous solutions of different ionic concentrations and pH values. After the DC electric fields were applied along the glass slide in horizontal direction, the diameter of central film and the thickness of meniscus film were measured by the interference method with an optical microscope.

Findings

The diameter of the central film decreases with the increase in the applied electric fields and declines at higher pH values while increases when the ionic concentration increases. The meniscus film becomes thicker with the increase in applied electric fields and is thicker in pH = 11 solution and thinner in pH = 3 and 1 mM NaCl solution. This is the first study of dynamic thin liquid film under DC electric field, which may be attributed to the balance of dielectrophoretic (DEP) force, colloidal force and the deformable characteristic of the oil droplet.

中文翻译：

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直流电场下的浮动油滴和载玻片之间的液体薄膜

假设

载玻片和浸入水溶液中的油滴之间的液膜（SLF）的形状受直流（DC）电场的影响。由中央膜区域和弯月形膜区域组成的液体膜形成在浮油滴和顶部玻璃载玻片之间。

实验

在不同离子浓度和pH值的水溶液中对SLF进行了实验研究。沿载玻片沿水平方向施加直流电场后，用光学显微镜通过干涉法测量中心膜的直径和弯月形膜的厚度。

发现

中心膜的直径随施加的电场的增加而减小，并在较高的pH值下减小，而在离子浓度增加时增大。弯月面膜随着施加电场的增加而变厚，在pH = 11的溶液中变厚，在pH = 3和1 mM的NaCl溶液中变薄。这是对直流电场下动态薄膜的首次研究，这可能归因于介电泳力，胶体力和油滴的可变形特性之间的平衡。