Chatterjee Jaideep
Hindustan Lever Research Center, 64 Main Road, Whitefield, Bangalore 560066, India.
J Colloid Interface Sci. 2007 Oct 1;314(1):199-206. doi: 10.1016/j.jcis.2007.05.051. Epub 2007 May 24.
This paper shows how 2 coupled Young-Laplace equations can be solved to predict the shapes of two coupled menisci formed in a capillary system. Experiments are performed, which demonstrate that the equilibrium volume of liquid retained in a vertical capillary, can be variable, even when all the properties of the system are invariant. This variability in liquid retention also leads to different equilibrium shapes of the top and bottom menisci. A coupled form of the Young-Laplace equation is solved to predict the two coupled menisci shapes. The curvature of the top meniscus is fitted to the experimentally recorded meniscus shape. The coupled Young-Laplace equation solution is used to predict the shape of the bottom meniscus. The shape of the bottom meniscus thus obtained, is shown to match the experimentally recorded bottom meniscus shape reasonably well. This observed coupling of the menisci has a significant impact on some porosimetric techniques which are based on liquid extrusion and explains why the volume of liquid that can be retained in a capillary can vary, under invariant conditions. Retention of liquids in capillaries is of interest in several applications like fabric wash.
本文展示了如何求解两个耦合的杨 - 拉普拉斯方程，以预测在毛细管系统中形成的两个耦合弯月面的形状。进行了实验，实验表明，即使系统的所有属性不变，垂直毛细管中保留的液体平衡体积也可能是可变的。这种液体保留的变异性还会导致顶部和底部弯月面的不同平衡形状。求解了杨 - 拉普拉斯方程的耦合形式，以预测两个耦合弯月面的形状。将顶部弯月面的曲率拟合到实验记录的弯月面形状。耦合的杨 - 拉普拉斯方程解用于预测底部弯月面的形状。由此获得的底部弯月面形状与实验记录的底部弯月面形状匹配得相当好。观察到的弯月面耦合对一些基于液体挤出的孔隙率测定技术有重大影响，并解释了为什么在不变条件下，毛细管中可保留的液体体积会发生变化。毛细管中液体的保留在诸如织物洗涤等多种应用中具有重要意义。
