Korean Journal of Chemical Engineering, Vol.40, No.5, 1086-1093, May, 2023
Bioinspired spindle-knotted structure fiber membrane prepared by modified coaxial electrospinning for water-in-oil emulsion separation
Inspired by the conformation of spider silks, fibers with multiscale spindle-knotted structures were fabricated via a one-step modified coaxial electrospinning method. Under a high-voltage electric field, hydrophobic silica polystyrene (PS) fibers coated poly (methyl methacrylate) (PMMA) fibers were integrated together during the electrospinning process. Due to the addition of hydrophobic gaseous SiO2 combining the spindle structure, a superhydrophobic fibrous membrane was prepared, and the bioinspired fibers achieved a superhydrophobic/superoleophilic performance for efficient emulsion separation. The results demonstrate that the incorporation of PS and SiO2 improved the efficiency of emulsion separation of the fabricated fibrous membranes by optimizing microstructure and wettability: Specifically, an extraordinary water contact angle under oil (162° ) and a satisfied oil contact angle under water (0°). For water-in-diesel emulsions, a high separation efficiency of 99.1% was obtained for membrane with PS addition of 4 wt%, which is greater than of pure PVDF membrane with SiO2 (75.5%). It performs better than most other membranes showing strong promise in grease purification and oily wastewater treatment.