In situ synthesis of three-dimensional electrospun polyacrylonitrile nanofiber network reinforced silica aerogel for high-efficiency oil/water separation

Abstract

In situ electrospun 3D polyacrylonitrile (PAN) nanofiber-reinforced (EPNR) silica aerogel monoliths were prepared through methyltriethoxysilane–trimethylchlorosilane modification followed by ambient pressure drying (APD). The 3D PAN nanofiber network was built into silica sol by liquid-assisted collection. Homodispersed and intertwined PAN nanofibers were well incorporated into the silica aerogel matrix. The APD-EPNR silica aerogel had a porosity of 90.9% and a BJH pore volume of 2.15 cm³ g⁻¹. Furthermore, the APD-EPNR silica aerogel monolith showed excellent flexibility and revealed a highly hydrophobic surface with a water contact angle of 145º. The APD-EPNR aerogel was suitable for removal of oil from water. The static mass of the APD-EPNR silica aerogel achieved 700%–1500% to various solvents and the aerogel can be recovered without obvious performance decline. The APD-EPNR silica aerogel mat also achieved oil/water separation with a separation efficiency of more than 99%. Hence, the prepared APD-EPNR silica aerogel has promising application for treatment of oil pollution.