Modulation of Polyether Ether Ketone (PEEK) Surfaces via High-Speed Femtosecond Laser Treatment and Perfluoropolyether-Based Polyurethane Coating.

Abstract

We report a rapid and scalable method for fabricating hierarchically microstructured polyether ether ketone (PEEK) surfaces using high-speed femtosecond laser treatment. The resulting structures exhibit two primary morphological features: cylindrical hills (11-16 μm in diameter) formed by ablation and a micro-/submicron-scale mesh originating from melt flow and resolidification. These features significantly modify surface wettability, increasing the water contact angle (WCA) up to 136° and promoting complete wetting by hexadecane. Subsequent deposition of ∼20 nm of a perfluoropolyether-based polyurethane coating further modifies surface properties, achieving superhydrophobicity (WCA ≈ 180°) and strong oleophobicity (HDCA of 90-120°). The reported WCA and HDCA values rank among the highest for laser-structured engineering polymers. This approach demonstrates the potential of femtosecond laser texturing combined with perfluoropolyether-based coating to create advanced, multifunctional PEEK surfaces. We expect that the surface treatment described in this work can be readily transferred to a number of other essential thermoplastic polymers and industrial applications, especially in the areas of water/oil repellency, ice-phobic coatings, biointerfaces, and adhesion.