Bioinspired Bionic Superhydrophobic Coating Based on Rosin Acid and TiO2 Nanoparticles for Oil–Water Separation and Anti-icing

Oily wastewater discharge in daily life and industry poses a major threat to the environment and human health. Recently, superhydrophobic materials for the treatment of oily wastewater have attracted much attention. Herein, bioinspired from blueberry and mussel, a superhydrophobic coating (RA-S@TiO2 coating) based on sulfhydryl-modified rosin acid (RA-S) and titanium dioxide nanoparticles (TiO2) was successfully prepared. To increase the micro/nano roughened structure on the material surface, TiO2 nanoparticles with better self-cleaning properties were used as one of the coating components. The prepared RA-S@TiO2 coating exhibited excellent superhydrophobicity (water contact angle greater than 153°) and superoleophilicity. What is more, the separation efficiency and flux of the RA-S@TiO2 coating for various oil–water mixtures were greater than 95% and 6759 L·m–2·h–1, respectively. It was clearly found that the separation efficiency and flux remained above 95% and 6451 L·m–2·h–1 even after 10 separations. Moreover, the RA-S@TiO2 coating exhibited desirable durability and stability as well as emulsion separation performance after the treatments. Droplets on the RA-S@TiO2 coating demonstrated desirable anti-icing performance with freeze delays up to 1200 s at −18 °C. Furthermore, life cycle assessment revealed that the environmental impact of the RA-S@TiO2 coating was significantly lower than that of the other two commercially available superhydrophobic materials. In conclusion, due to the environmental advantages of the RA-S@TiO2 coating, it provided a sustainable solution for the preparation of a superhydrophobic material, which had a promising future in the fields of oil–water separation and anti-icing.