Condensation dynamics at the solid-liquid interface on micro- and nano-structured surfaces by Total Internal Reflection method

提出了一种将全内反射法与光学显微镜相结合的实验装置，用于近距离观察凝结液滴与固体表面的动态相互作用。建立了由长距离光学显微镜镜头Keyence VH-Z50L(空间分辨率为6.1 x 4.6 mm^2,500 X时为610 x 460微米^2)和一台CCD摄像机(500帧/秒)组成的可视化装置。通过使用微米x-y工作台移动视面/焦面，首次获得了直接观察固-液/气界面的实验观测结果。在固-液/气界面的观察揭示了凝结液滴与固体结构之间的密切作用以及凝结液滴与油之间的密切相互作用。实验结果表明，与单一纳米结构的锂离子相比，多层微/纳米结构锂离子交换膜具有较低的固体-凝聚直接相互作用。与纳米结构的LIS相比，低直接液滴-固体相互作用提供了更低的冷凝液与注入润滑剂的分级表面的粘附性，导致更小的液滴脱落，这是高传热的特征。由于PI转移到爱丁堡大学新的学术职位后持续时间较短，设置的第二部分包括：激光、蓝宝石冷却阶段、卤素灯、光学显微镜侧视图，尚未完全敲定。

A new experimental setup combining Total Internal Reflection methodology coupled with optical microscopy was proposed to observe closely the dynamic interactions between condensing drops and solid surfaces. Visualisation setup consisting of a long working distance optical microscope lens Keyence VH-Z50L (spatial resolutions 6.1 x 4.6 mm^2 at 50x, 610 x 460 microns^2 at 500x coupled with a CCD camera (500 frames per seconds) was built.Optical microscopy was applied to image condensation of drops on lubricant infused surfaces LIS. By shifting the plane of view/focus using a micrometer x-y stage the first experimental observations looking directly at the solid-liquid/gas interface were acquired. Observations at the solid-liquid/gas interface reveal the intimate interactions between condensing drops and the solid structures as well as the intimate interactions between the condensing drops and the oil. Observations put forward the lower solid-condensate direct interactions in the case of hierarchical micro-/nano-structured LIS when compared to solely nano-structured LIS. The lower direct drop-solid interactions offer in turn lower adhesion of the condensate to the lubricant infused hierarchical surface inducing the shedding of smaller drops when compared to nano-structured LIS, which is characteristic of high heat transfer.Due to short duration of the grant since the PI moved to a new academic position at The University of Edinburgh, the second part of the setup comprising; laser, sapphire cooling stage, halogen lamps, optical microscopy side view, was not completely finalised.