Study of surface modification of tungsten nanostructures for superhydrophobic applications

摘要

In this work, we studied the impact of the modification of the structure of tungsten surfaces through physical vapor deposition (magnetron sputtering), electrochemical (anodization and electropolishing), and thermal (annealing) processes on the wettability of the designed surfaces. We observed static contact angle values ranging from around 10° to above 150° showing the importance of the techniques used to produce the surfaces. We noticed that the annealing process tends to increase the wettability, transforming hydrophobic surfaces into hydrophilic surfaces. We also observed that electropolishing affects the wettability in such a way that the contact angles of pre-chemically treated tungsten foils tend to decrease after coating when the electrochemical process is judged efficient due to a shadowing effect during the glancing angle deposition. Finally, we introduce a novel technique to create a dual micro-/nano-structure, preferable for superhydrophobicity. This novel technique may have tremendous implications for anti-icing applications.