Mostowfi Farshid, Czarnecki Jan, Masliyah Jacob, Bhattacharjee Subir
Department of Mechanical Engineering, University of Alberta, Edmonton, AB, T6G 2G8, Canada.
J Colloid Interface Sci. 2008 Jan 15;317(2):593-603. doi: 10.1016/j.jcis.2007.09.068. Epub 2007 Sep 29.
An experimental technique is developed for assessing stability of thin liquid films by application of electric potential to compress the liquid film and to simultaneously measure the electrical properties of the system. The concept involves creating a thin film at the intersection of two microchannels etched onto a glass substrate. A ramped DC potential difference is applied across the film, which develops an electrical stress across the film. Increasing the potential to a critical value leads to the rupture of the film. The critical potential is used to assess the stability of the liquid film. Small channel dimensions in this microfluidic platform allow characterization of thin films formed between micron-sized droplets representing systems with high capillary pressures, analysis of which are typically beyond the scope of conventional thin film characterization techniques. The results of DC potential breakdown of films show that critical potential can be considered as a measure of thin film stability.
开发了一种实验技术，通过施加电势来压缩液膜并同时测量系统的电学性质，以评估薄液膜的稳定性。该概念涉及在蚀刻在玻璃基板上的两个微通道的交叉处形成薄膜。在薄膜上施加一个斜坡直流电势差，这会在薄膜上产生电应力。将电势增加到临界值会导致薄膜破裂。临界电势用于评估液膜的稳定性。这个微流体平台中的小通道尺寸允许对代表具有高毛细管压力系统的微米级液滴之间形成的薄膜进行表征，而传统薄膜表征技术通常无法对其进行分析。薄膜的直流电势击穿结果表明，临界电势可被视为薄膜稳定性的一种度量。
