A robust UiO-66-F4/polysulfone nanofibrous membrane for efficient separation of hot oil-water mixture and emulsion

A hydrophobic metal-organic framework (MOF) nanofibrous membrane (NFM) with excellent comprehensive properties was successfully fabricated by a simple method. Benefiting from the excellent hydrophobicity, chemical stability, thermal stability and good structural fit of UiO-66-F 4 and polysulfone (PSF), the UiO-66-F 4 /PSF NFM has been directly prepared via co-electrospinning of UiO-66-F 4 and PSF without any additional modifications. Characterization with PXRD, FT-IR and XPS indicated that UiO-66-F 4 crystals were effectively incorporated into PSF fibers and their crystal structure was not destroyed. The obtained UiO-66-F 4 /PSF NFM exhibited improved hydrophobicity compared with the parent materials, even after the treatment with heat, acid or alkali solutions. Therefore, it was competent for separating different forms of oil-contaminated water, including oil-water mixture and water-in-oil emulsion, even in harsh conditions. In the case of hot oil-water mixture, UiO-66-F 4 /PSF NFM still showed a separation efficiency of about 99 % and an oil flux of 1036 L m −2 h −1 . More importantly, the separation efficiency remained relatively stable during 30 cycles of separation, indicating that UiO-66-F 4 /PSF NFM can meet the requirements of long-term use. In view of this, UiO-66-F 4 /PSF NFM had the potential to treat practical oily wastewater in harsh environments.