界面探针法测量液滴与固体壁面间相互作用力

Determination of interaction force between droplet and solid surface using droplet probe

液滴与固体壁面间相互作用力的测量与研究是深入理解润湿机理、调控受限空间内多相流动行为的基础。以液滴轮廓形变为原位微作用力探针,通过拍摄并分析液滴与固体壁面作用过程中轮廓形态变化实现了液滴与固体壁面间相互作用力的测量,测量结果与商用精密微作用力测量仪结果符合良好。相较近年来文献报道的原子力显微镜(AFM)与表面力仪(SFA)测定方法,本方法无须借助外部精密机械探针,具有操作简单、过程可视、成本低廉、不受研究对象透光性限制等优势。最后利用本方法测定了水相环境中十四烷液滴靠近与远离固体壁面时所受的作用力,考察了水相组成对作用力的影响,并发现液滴与壁面间的总斥力仅取决于液滴的形变能力。

The determination of interaction force between droplet and solid surface is of fundamental importance for understanding wetting mechanism and controlling multiphase flow behavior in confine space.In this study,the interaction force between droplet and solid surface is determined by using droplet profile as a probe.The interaction force is calculated by capturing and analyzing the droplet deformation during the interaction.The results are in good agreement with those obtained by the precise commercial weighing sensor.Compared with the atomic force microscope(AFM)and surface force meter(SFA)measurement methods reported in the literatures in recent years,this method does not require external precision mechanical probes,and has the advantages of simple operation,process visualization,and low cost.It is not limited by the light transmittance of the research object.Therefore,it has the advantage of simple,visible,low cost,and not limited to transparent objects.Finally,the dynamic interaction force between the tetradecane droplet and solid surface in various aqueous solutions is determined by the new method.The influence of the component of aqueous solutions is investigated.It is found that the total repulsive force only depends on the droplet deformability.