Langmuir · 2009 · 783 citations · 34 references
Natural SciencesMaterials EngineeringMaterials ScienceMetallic MaterialsSurface ChemistrySurface ScienceNanostructured SurfacesSurface HydrophobicitySurface ModificationSurface MorphologySurface PhysicsSurface RoughnessContact Angle HysteresisSuperhydrophilic SurfacesSuperhydrophobic SurfacesSurface WettabilitySurface WettingSurface Wetting BehaviorWettingWetting Phenomena
The study demonstrates that femtosecond laser irradiation of metal alloys creates dual‑scale roughness that initially yields superhydrophilic surfaces. Over time the laser‑textured surfaces transition from superhydrophilic to nearly superhydrophobic (contact angles ~150°) with low hysteresis (2–6°), a change driven by surface carbon content and the interplay of morphology and chemistry.
This work shows that after creating certain dual scale roughness structures by femtosecond laser irradiation different metal alloys initially show superhydrophilic behavior with complete wetting of the structured surface. However, over time, these surfaces become nearly superhydrophobic with contact angles in the vicinity of 150° and superhydrophobic with contact angles above 150°. The contact angle hysteresis was found to lie between 2 and 6°. The change in wetting behavior correlates with the amount of carbon on the structured surface. The explanation for the time dependency of the surface wettability lies in the combined effect of surface morphology and surface chemistry.
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Wettability of porous surfaces
A. B. D. Cassie, S. Baxter · Transactions of the Faraday Society · 1944 · 13.5K citations
Super‐Hydrophobic Surfaces: From Natural to Artificial
Libang Feng, Shuhui Li, Yuanxin Li et al. · Advanced Materials · 2002 · 4.4K citations