电场对液滴界面张力及动力学特征影响的研究进展

Review on the effect of electric field on interfacial tension and dynamics of liquid droplets

电场是改变液滴界面张力的重要因素,施加不同类型的电场对驱动微流体运动、变形、分裂及合并等行为起着至关重要的作用,该技术广泛用于微液滴操控、电子显示和原油脱水等领域,并具有潜在的应用前景。文中综述了电场作用下微液滴气-液、气-固与液-液交界面张力的变化,分析了与界面张力对微液滴运动学行为影响相关的实验现象及模拟成果;指出电场作用下气-液交界面处表面张力的变化趋势,因实验及模拟方法不同目前仍存在较大争议;探讨了直流电和交流电对电润湿过程液滴铺展的不同影响和液滴形态振荡特征;分析了直流电、交流电及电脉冲对电破乳过程中液滴运动行为的重要作用。总结了电场对液滴界面张力影响研究中存在的问题,并提出了值得进一步深入研究的可能方向。

The effect of electric field on the interfacial tension of liquid droplets is of crucial importance to the movement,deformation,splitting and merging of micro fluids actuated by electric fields,which is extensively applied in micro drop control,electronic display,crude dehydration,etc.,and its applications have many potential prospects. In this paper,the effects of electric field on the interfacial tension at gas-liquid,gas-solid and liquid-liquid interface are reviewed comprehensively. The mechanism of micro droplet dynamics induced by interfacial tensions in electric fields is discussed. The related experimental studies and simulation results are summarized. The trend of gas-liquid interfacial tension in the electric field is still controversial due to the difference in the experiments and simulation. The diversiform effects of DC and AC electric fields on the spreading of the droplet and the oscillating characteristic in the process of electrowetting are discussed. Similarly,the remarkable effects of DC,AC and pulse electric field on the movement of a droplet in the process of electric emulsification are analyzed. In addition,based on research progress and existing problems,the possible prospects of electric field on interfacial tension and dynamics of liquid droplets are suggested.