Maximum spreading behavior of a water droplet on the aluminium surfaces with different wettabilities

Abstract

This work demonstrates the maximum spreading behavior of water droplets on prepared surfaces: superhydrophilic (etched), hydrophilic (inherent nature), hydrophobic (treated with hexadecyltrimethoxysilane (HDTMS), and superhydrophobic (etched and HDTMS treated). Here, a simple chemical etching and immersion approach were used to modify the surfaces. Altering one surface property to the next shows a significant variation in the wetting behavior. The change in the wettability of the aluminium surface depends on its surface roughness and surface chemistry. The wettability of the fabricated surfaces was determined via water contact angle (WCA) measurement using a goniometer. A field emission scanning electron microscope (FESEM) and a 3-D optical non-contact profilometer were used to analyze the surface morphology and surface roughness of all manufactured surfaces, respectively. Additional features such as the droplet dynamics property of all surfaces were studied in detail. Finally, the experimental results for the maximum spreading factor were compared to the existing model.