Superhydrophobic laser ablated PTFE substrates

• Published in: Applied surface science Vol. 349; pp. 715 - 723
• Main Authors: Falah Toosi, Salma, Moradi, Sona, Kamal, Saeid, Hatzikiriakos, Savvas G.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.09.2015
• Subjects: Beams (radiation); Contact angle; Contact angle hysteresis; Laser ablation; Laser beams; Micro/nano pattern; Morphology; Nanostructure; Polytetrafluoroethylenes; Polytetrafluoroethylne; Scanning; Superhydrophibicity; Surface wettability; Wettability; Surface wettability; Laser ablation; Contact angle hysteresis; Polytetrafluoroethylne; Superhydrophibicity; Micro/nano pattern
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2015.05.026

•Uniaxial and biaxial patterns fabricated on PTFE surface are responsible for superhydrophobic behavior of the surface.•Biaxial scan artificially creates high level of dual scale roughness on the PTFE surface with high contact angles (CAs) and low contact angle hysteresis (CAH) similar in all directions.•Contact angle of biaxially scanned surfaces can be as high as 170° and their contact angle hysteresis can reach as low as 3°. The effect of femtosecond laser irradiation process parameters (fluence, scanning speed and beam overlap) on the wettability of the resulted micro/nano-patterned morphologies on polytetrafluoroethylene is studied in detail. Several distinctly different micro/nano-patterns were fabricated including uniaxial and biaxial patterns. In particular, using biaxial scanning well defined pillared morphology was fabricated. The wettability analysis of the biaxially scanned samples revealed enhanced superhydrophobicity exhibiting high contact angles and low contact angle hysteresis.