Synthesis and sustainable application of fluorosilicon-based superhydrophobic coatings for high-salt wastewater treatment: A short two-step method

A fluorosilicon-based superhydrophobic coating (ER-SiO 2 /PVDF/SFT) was engineered by a novel non-hydrolytic two-step methodology, demonstrating exceptional fouling resistance in hypersaline wastewater treatment. The coating achieved a water contact angle of 154.3 ​± ​0.5°, representing a 12 ​% increase over epoxy resin (ER) reference coatings – and effectively repelled organic contaminants (ethylene glycol contact angle: 148.8 ​± ​1.8°). Antifouling efficiency reached 70 ​% against CaCO 3 fouling deposits in simulated two kinds of high-salt fouling solution, attributable to ultralow surface energy and biomimetic hierarchical roughness. Long-term thermal fouling tests revealed <5 ​% hydrophobicity decay, which would save energy in thermal evaporation. The short two-step method not only prevents fouling with minimal operational complexity but also facilitates easy reapplication, reducing material waste and chemical usage while supporting a circular economy in industrial water reuse. This scalable, low-waste coating supports Zero Liquid Discharge (ZLD) initiatives and UN Sustainable Development Goals 6 and 12, making it ideal for industrial applications and sustainable resource consumption. • A superhydrophobic coating named ER-SiO 2 /PVDF/SFT is prepared by two step method. • The superhydrophobic coating increased the WCA of the substrate dramatically. • The anti-fouling efficiency of ER-SiO 2 /PVDF/SFT coating is over 70 ​%. • The CA of ER-SiO 2 /PVDF/SFT coating still retains 145° after 7-day fouling tests. • Preparation of superhydrophobic coatings by a shorting two-step method is feasible.