A durable biomimetic superhydrophilic/underwater superoleophobic fabric bed for highly efficient emulsion separation. (June 2022) - Zhou, Yi
Abstract: A superhydrophilic/underwater superoleophobic fabric was fabricated via an immersion process in buffer solution of gallic acid (GA) and polyethyleneimine (PEI) and a short-term complexation process with cupric ions (Cu 2+ ). The fabric shows superhydrophilicity with a water contact angle (WCA) of 0° and underwater superoleophobicity with an underwater oil contact angle (UWOCA) of 162.2 ± 2.4°. Its superwettability can be kept after harsh acid/base/salty treatment, 1000 g sand impact and 50 cycles of tape-peeling, demonstrating outstanding chemical and physical durability. A fabric bed constructed by as-prepared fabrics was used for separating surfactant-stabilized toluene/isooctane/petroleum ether/1, 2-dichloroethane-in-water emulsions, with separation efficiencies all over 99.1%. The separation efficiency could be retained above 99.1% after repeated separation, indicating excellent reusability of the fabric bed. Graphical Abstract: ga1 Highlights: Underwater superoelophobic fabric was prepared by co-depositing GA/PEI particles and complexing with cupric ions. The fabrication is facile and green with inexpensive raw materials. The fabric shows excellent chemical and physical stability. The fabric bed indicates high separation efficiency and reusability for emulsion separation.