Oriented polycaprolactone-carbon black/SiO2 fibers with bionic superhydrophobic surfaces as a highly efficient oil–water separator

Abstract

Inspired by the surface structure of rice leaves, an eco-friendly polycaprolactone-carbon black/SiO₂ (PCL-C/SiO₂) membrane with an oriented arrangement was successfully prepared. The oriented arrangement of PCL fibers was achieved by doping carbon black (CB) nanoparticles. Owing to the addition of carbon black, the SiO₂ aerogel was uniformly dispersed along the PCL fiber, which generated a micro-/nanostructure of the bionic rice leaf. The PCL-C/SiO₂ membrane showed superhydrophobicity, and the water contact angle was 169.0° ± 0.2°. For oil–water mixtures, the PCL-C/SiO₂ membrane exhibited an ultrahigh separation efficiency of 99.93° ± 0.01% and a permeate flux of 19 000 ± 1000 L m⁻² h⁻¹. For water-in-oil emulsions with surfactant stabilization, the PCL-C/SiO₂ membrane exhibited excellent separation efficiency (99.90% ± 0.01%) and permeate flux (4966.7 ± 152.8 L m⁻² h⁻¹). Furthermore, the PCL-C/SiO₂ membrane showed superior cycling stability, self-cleaning properties, and resistance to wear and corrosion. This study presents a method for the controllable design of bionic polymer separation membranes.