One-pot in-situ deposition toward fabricating superhydrophobic fiberglass membranes with composite microstructure for fast water-in-oil emulsions separation

Abstract

The separation of oily wastewater, especially surfactant-stabilized water-in-oil emulsions, has become a pressing global challenge. Herein, to achieve ultrafast and efficient separation of water-in-oil emulsions, this work took advantage of the Dodecyltrimethoxysilane (DTMS)-modified TiO2 sol to prepare a superhydrophobic fiberglass (FG) membrane via a facile one-pot in-situ deposition technique. The unique composite microstructure: stalactite-shaped TiO2-SiO2 composite nanoparticles and multi-layer rough fibers were constructed on the fibrous membranes, which significantly increased the roughness and led to a water contact angle of 162.7°. As-prepared composite microstructures combined the capture, coalescence, and interception effects to achieve ultrafast gravity-driven separation of surfactant-stabilized emulsions, with a flux up to 3130.4 L m−2h−1 for surfactant stabilized water-in-hexane and high separation efficiency above 99% for various emulsions. Additionally, the prepared membrane exhibited an excellent cyclic adsorption capacity of 4.25–19.07 gg−1 and high stability. Such an easy, cost-efficient one-pot in-situ deposition method provides a brand-new solution to fabricate superhydrophobic membranes for efficient separation of water-in-oil emulsions, thus exhibiting great potential in applications of domestic wastewater treatment, oil spill treatment, and oil industry development.