A facile, sustainable and effective fabrication of environmentally safe, durable multifunctional superhydrophobic fabric with self-cleaning and oil–water separation properties

Polyester (PET) fabrics with superhydrophobic features are highly desirable for oil–water separation applications. Herein, flexible, breathable and superhydrophobic Polyester fabrics (ODPFs) were fabricated via a facile, environmentally friendly, low-cost and high-efficiency two-step process for a broad application scope of textiles and soft materials with different apertures, specifications and dimensions. The ODPFs were etched by a green deep eutectic solvent (DES) consisting of choline chloride and oxalic acid and coated with Octadecyltrichlorosilane (OTS)/water mixture colloidal aggregates, without the use of any toxic organic solvents. The results reveal that the ODPFs exhibit a water contact angle of 160.9°, allowing it to repel various liquids like common daily solutions, acids, and alkaline solutions. Furthermore, the ODPFs possess exceptional self-cleaning properties and oil–water separation with a high separation efficiency (>99.3 %) and excellent durability against 100 cycles on sandpaper (400 mesh). In addition, DES was demonstrated to improve the surface roughness and assisting silicone polymers to further enhance the hydrophobicity of PET, making it ideal for applications such as anti-fouling, self-cleaning, anti-icing, and oil–water separation. The presented superhydrophobic strategy is considered feasible to multiple substrates, offering novel perspectives on extending the utilization of DES and enabling the practical application of fluorine-free superhydrophobic fabrics.