Long-term influence of laser-processing parameters on (super)hydrophobicity development and stability of stainless-steel surfaces

Gregorčič, Peter (avtor), Conradi, Marjetka (avtor), Hribar, Luka (avtor), Hočevar, Matej (avtor)

Controlling the surface wettability represents an important challenge in the field of surface functionalization. Here, the wettability of a stainless-steel surface is modified by 30-ns pulses of a Nd:YAG marking laser (λ = 1064 nm) with peak fluences within the range 3.3–25.1 J cm$^{−2}$. The short- (40 days), intermediate- (100 days) and long-term (1 year) superhydrophilic-to-(super)hydrophobic transition of the laser-textured surfaces exposed to the atmospheric air is examined by evaluating its wettability in the context of the following parameters: (i) pulse fluence; (ii) scan line separation; (iii) focal position and (iv) wetting period due to contact angle measurements. The results show that using solely a short-term evaluation can lead to wrong conclusions and that the faster development of the hydrophobicity immediately after laser texturing usually leads to lower final contact angle and vice versa, the slower this transition is, the more superhydrophobic the surface is expected to become (possibly even with self-cleaning ability). Depending on laser fluence, the laser-textured surfaces can develop stable or unstable hydrophobicity. Stable hydrophobicity is achieved, if the threshold fluence of 12 J cm$^{−2}$ is exceeded. We show that by nanosecond-laser texturing a lotus-leaf-like surface with a contact angle above 150° and roll-off angle below 5° can be achieved.

• Jezik: Angleški jezik
• Ključne besede: laser surface engineering, wetting, superhydrophobic surfaces, laser material processing, surface modification
• Vrsta gradiva: Članek v reviji
• Tipologija: 1.01 - Izvirni znanstveni članek
• Organizacija: FS - Fakulteta za strojništvo
• Status publikacije: Objavljeno
• Različica publikacije: Objavljena publikacija
• Leto izida: 2018
• Št. strani: 15 str.
• Številčenje: Vol. 11, iss. 11, art. 2240
• PID: 20.500.12556/RUL-105246
• UDK: 621.7(045)
• ISSN pri članku: 1996-1944
• DOI: 10.3390/ma11112240
• COBISS.SI-ID: 16343835
• Datum objave v RUL: 14.11.2018

Gradivo je del revije

• Naslov: Materials
• Skrajšan naslov: Materials
• Založnik: MDPI
• ISSN: 1996-1944
• COBISS.SI-ID: 33588485

Licence

• Licenca: CC BY 4.0, Creative Commons Priznanje avtorstva 4.0 Mednarodna
• Povezava: http://creativecommons.org/licenses/by/4.0/deed.sl
• Opis: To je standardna licenca Creative Commons, ki daje uporabnikom največ možnosti za nadaljnjo uporabo dela, pri čemer morajo navesti avtorja.
• Začetek licenciranja: 11.11.2018

Sekundarni jezik

• Jezik: Slovenski jezik
• Ključne besede: laserski inženiring površin, superhidrofobne površine, laserske obdelave