| Summary: | 碩士 === 國立臺灣大學 === 機械工程學研究所 === 95 === At the beginning of this article, the situation of single colloid interacting with liquid is concerned. It is found that when the colloid is hydrophilic, the vertical force necessary to pull the colloid away from liquid is larger than that necessary to put the colloid into liquid. The reverse is true when the colloid is hydrophobic. The interaction between two colloids is also discussed. When two colloids are on the liquid-air interface, they attract or repel each other due to surface tension on the liquid-air interface. When the two colloids are at the same height above the far-field-liquid level, they attract each other. If their positions are both higher than far-field-liquid level but they are not at the same height, the interaction between them is attractive at long distance, and turns to be repulsive at some critical distance with a stable equilibrium. When one colloid is above the far-field-liquid level and the other is below this level, the interaction between the two colloids is repulsive. In other word, two colloids attract or repel each other depends on the elevations of colloids and the meniscus shape between colloids. Besides, this study successfully got the analytical solution of meniscus shape between colloids from Young-Laplace equation, and analysis variation of interaction between colloids and total energy in all situation. Finally, a experiment of measuring shape of meniscus between colloids is set up. We compared the experiment data with the analytical solution. By taking image of meniscus shape, we can also analysis interaction between colloids.BY taking image of meniscus shape, we can analysis interaction between colloids .
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