Facile Preparation of a Fluorine‐Free,Robust, Superhydrophobic Coating through Dip Coating Combined with Non‐Solvent Induced Phase Separation (Dip‐Coating‐NIPS) Method

Superhydrophobic surfaces based on non‐fluorinated materials and facile fabrication techniques are of great practical value with respect to environmental friendliness and industrial applications. In this work, a fluorine‐free, superhydrophobic coating with hierarchical surface structure and low surface energy is successfully fabricated on various substrates through a recently developed dip coating combined with non‐solvent induced phase separation (dip‐coating‐NIPS) method. A bio‐based polymer, poly(l ‐lactic acid), and commercially available hydrophobic SiO₂ nanoparticles, are used. The fabricated coating exhibits superhydrophobicity, with a static water contact angle (WCA) of 155.7° ± 1.4° and contact angle hysteresis (θ_Hys) of 5.2° ± 0.4°. The results from stability tests demonstrate excellent mechanical durability and chemical stability of the superhydrophobic coating. Finally, the fabricated coating is successfully applied in water–oil separation with superior efficiency. This simple, cost‐effective, and time‐efficient method may provide an effective way for the design of nonfluorine‐based environmentally friendly membranes for separation applications.