On the wetting behavior of laser-microtextured stainless steel using Direct Laser Interference Patterning

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Frederic Schell - , Fraunhofer Institute for Material and Beam Technology (Author)
  • Sabri Alamri - , Fraunhofer Institute for Material and Beam Technology, Fusion Bionic GmbH (Author)
  • Tobias Steege - , Fraunhofer Institute for Material and Beam Technology (Author)
  • Christoph Zwahr - , Fraunhofer Institute for Material and Beam Technology (Author)
  • Tim Kunze - , Fraunhofer Institute for Material and Beam Technology, Fusion Bionic GmbH (Author)
  • Andres Lasagni - , Chair of Laser-based Manufacturing, Fraunhofer Institute for Material and Beam Technology (Author)

Abstract

Microtextures generated by pulsed lasers allow for changing the surface properties of a wide palette of materials by replicating nature's most effective topographies. In the case of laser-induced microtextures, the surface's wetting properties evolve over time and eventually stabilize. The size of the fabricated features and the initial surface roughness strongly influence this transition and play a key role in the determination of the final wetting state. This work aims to study the wettability of textured stainless-steel with two different surface finishes. Nanosecond Direct Laser Interference Patterning was applied to fabricate a wide range of dot-like microtextures that were evaluated in terms of surface roughness. The water contact angle was monitored for up to 90 days, showing a transition from hydrophilic to hydrophobic. Applying the Wenzel model, the wettability transition was analyzed in regard to surface roughness, and the transition of the average Young contact angle could be extrapolated. In the steady-state, the textured surfaces exhibited the rose-petal effect, where contact angles up to 154.4 were attributed to the microtextures, while a simultaneous high drop adhesion could be related to the initial surface finish. Measurements with water and diiodomethane showed that the textures were both hydro-phobic and oleophilic in the steady-state. The surface free energy was estimated and decreased on all textures compared to the untextured reference.

Details

Original languageEnglish
Article number128869
Number of pages12
JournalSurface & coatings technology
Volume447
Publication statusPublished - 15 Oct 2022
Peer-reviewedYes

External IDs

Scopus 85138037665

Keywords

Keywords

  • Dlip, Microstructures, Superhydrophobic, Surface free energy, Wettability