Superhydrophobic-Superoleophilic SiO₂/Polystyrene Porous Micro/nanofibers for Efficient Oil-Water Separation

SiO₂/polystyrene porous micro/nanofibers with superhydrophobic and superoleophilic properties were prepared by facile electrospinning method. The spindle-beads-on-string structured fibers were found to be more hydrophobic than those without the beads. The doping of nano-SiO₂ endowed the fibers with porous structure, and thus further increased the water contact angle from 139° to 153°. Simultaneously, the oil contact angle of 0° was obtained. The superhydrophobic-superoleophilic micro/nanofibers could selectively absorb oil from water within eight seconds. The oil sorption process followed pseudo-first order kinetic model. The absorption mechanism was proved to be physical encapsulation by Fourier transform infrared technique. The maximum sorption capacity for highly viscous silicone oil was up to 122.7 g/g. It is higher than many recently reported values. The porous micro/nanofibers exhibit significant value in oil-water separation.