Development of a novel ECTFE melt-blown nonwoven materials and its application in oil-water separation

The removal of oil from water surfaces is crucial for protecting the environment and living organisms from the hazards posed by industrial oily wastewater and offshore oil spills. However, achieving enhanced mechanical robustness, corrosion resistance, and durability in oil-water separation membranes presents a significant challenge. In this study, poly(ethylene chlorotrifluoroethylene) (ECTFE) resin, a novel semicrystalline polymer material composed of alternating ethylene and chlorotrifluoroethylene molecules, was fabricated into melt-blown fabric (MB) by melt-blowing technology. By optimizing the side wind temperature, collector distance, roller speed, and hot air pressure, ECTFE MB with superior mechanical properties was established. Additionally, the obtained ECTFE MB exhibited excellent hydrophobicity with a water contact angle reaching 127.8°. The separation efficiency for various oil-water mixtures (oil phase including carbon tetrachloride, petroleum ether, dichloromethane, n-hexane, and isooctane) exceeded 99 %. Furthermore, after 90 cycles of oil-water separation, ECTFE MB maintained high flux (72183.16 L m⁻² h⁻¹) and separation efficiency of 99.40 % when carbon tetrachloride was used as oil phase. Notably, ECTFE MB demonstrated exceptional resistance to harsh environments, including strong acids, bases, and mild high temperature. The investigation of failure modes of ECTFE MB revealed that the primary failure mode of ECTFE MB was the disruption of the oil-water interface. The maximum water height that the ECTFE MB could withstand was 1376 mm. Consequently, ECTFE MB exhibit excellent mechanical properties, chemical stability, and cycling stability, indicating the potential application in the field of oil-water separation.