Pan/ Cb Spheres Modified Pan/Pvp Dual Amphiphilic Porous Nanofiber Membranes for High-Performance Oil-Water Separation

Abstract

The efficient treatment of oily wastewater remains a significant challenge, particularly the rapid separation of emulsions under gravity-driven conditions. Among existing governance strategies, membrane separation has attracted considerable interest due to its operational efficiency and simplicity. In this study, by incorporating polyvinylpyrrolidone (PVP) via electrospinning, we successfully transformed the weakly hydrophobic polyacrylonitrile (PAN) fiber membrane into an amphiphilic material. Subsequent hot water treatment enhanced the specific surface area and porosity of the fiber membrane. To further optimize membrane performance, PAN/carbon black (CB) microspheres were spray on fiber surfaces via electrostatic spraying, creating microscale roughness to improve interfacial properties. The resulting porous amphiphilic PAN/PVP-PAN/CB fiber membrane exhibited exceptional separation performance for both oil-water mixtures and emulsions under gravity, achieving remarkable water fluxes of approximately 62,946.4 L·m⁻²·h⁻¹ (mixtures) and 1780.4 L·m⁻²·h⁻¹ (emulsions), with separation efficiencies exceeding 99% for all systems. The membrane also demonstrated robust cycling stability. This work presents a novel PAN/PVP-CB/PAN nanofibrous membrane with exceptional oil-water separation capability and practical processability, offering a sustainable material solution for environmental governance.

Keywords: gravity-driven, membrane separation, electrospinning, amphiphilic, electrostatic spraying