Nanostructured superhydrophobic surfaces show promise as promoters of dropwise condensation and may lead to significant efficiency improvements in numerous industrial processes. Droplets with diameters below ~10 µm account for the majority of the heat transferred during dropwise condensation but their growth dynamics on superhydrophobic surfaces have not been systematically studied. Due to the small droplet size, the dynamic nature of the process, and the complex topography of the surface, Environmental Scanning Electron Microscopy (ESEM) is the only method capable of capturing the growth dynamics of droplets in the sub-10 µm regime. By studying electron beam heating effects on condensed water droplets we establish a magnification limit below which the heating effects are negligible and use this insight to study the mechanism of individual drop growth.
Citation: Applied Physics Letters
Pub Type: Journals
ESEM, condensation, nanostructures, superhydrophobic