Raw data (Wetting angles) from Characterization of interface properties of fluids by evaporation of a capillary bridge

The surface properties between two non-miscible fluids are key elements to understand mass transfer, chemistry and bio-chemistry at interfaces. In this paper, surface properties are investigated in evaporating and non-evaporating conditions. A capillary bridge between two large plates (similarly as a Hele-Shaw cell) is considered. The temporal evolution of surface forces and mass transfers due to evaporation of the liquid are measured. The force depends on surface properties of the substrate. It is adhesive in the wetting case and repulsive in the non-wetting case. The force is also shown to depend linearly on the volume of the capillary bridge <i>F</i> ∝ <i>V</i>₀ and inversely to the height of the bridge. Modelling is performed to characterize both surface force and evaporation properties of the capillary bridge. The evaporation is shown to be diffusion driven and is decoupled from the bridge mechanics.

两种不互溶流体之间的表面特性，是理解界面处传质、化学及生物化学过程的关键要素。本文针对蒸发与非蒸发工况下的流体表面特性展开研究，本研究考虑两块大平板间形成的毛细桥（capillary bridge）结构，其原理与赫勒-肖池（Hele-Shaw cell）类似。研究人员对液体蒸发引发的表面力随时间的演化规律以及对应的传质过程进行了定量测量。该表面力的大小取决于基底的表面特性：在润湿工况下表现为粘附力，在非润湿工况下则表现为排斥力。研究同时发现，表面力与毛细桥的体积V₀呈线性正相关，且与桥体高度呈反比关系，即F ∝ V₀。本研究通过建模手段，对毛细桥的表面力与蒸发特性进行了系统表征。实验结果表明，蒸发过程由扩散机制主导，且与桥体的力学行为完全解耦。