Gas Bubble in Liquid Film under External Electric Field

5 Gas Bubble in Liquid Film under External Electric Field 

In the past decade, effects of an EEF on the properties of lubrication and wear have attracted significant attention. Many experimental results indicate that the friction coefficient changes with the intensity of the EEF on tribo-pairs. These phenomena are thought to be that the EEF can enhance the electrochemical reaction between lubricants and the surfaces of tribo-pairs, change the tropism of polar lubricant molecules, or help the formation of ordered lubricant molecular layers [51,73-77]. An instrument for measuring lubricant film thickness with a technique of the relative optical interference intensity (ROII) has been developed by Luo et al. [4,48,51,78] to capture such real-time interference fringes and to study the phenomenon when an EEF is applied, which is helpful to the understanding of the mechanism of thin film lubrication under the action of the EEF. 

An interesting phenomenon that some gas microbubbles emerged in the thin liquid film in a nanogap under an EEF was observed by Luo s group [78-80]. They have investigated the influence factors on and the mechanism of the emergence of these micro-bubbles. 

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TABLE 8—Physical pressure). parameters of experimental liquid samples (23°C and normal atmosphere 

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