Engineering electrospun hydrophobic SiO2 nanofibers via organosilica-based click chemistry modification for ultrafast oil-water separation

Oil-water separation is a vital process across various industries, where membrane separation stands out as a promising, energy-efficient solution. Despite its potential, the widespread application is hindered by the limited durability of existing membrane surface engineering effects. This study introduces an innovative fabrication strategy to create a superhydrophobic and durable nanofibrous membrane for efficient oil-water separation. Utilizing electrospinning and a two-step sequential covalent-bonding dip-coating process, the membrane was chemically decorated with vinyl trichlorosilane, followed by a thiol-ene “Click” reaction with 1H, 1H, 2H, 2H-perfluorodecanethiol, resulting in a stable superhydrophobic and oleophilic surface. The membrane exhibited high permeation fluxes for various organic solvents, achieving separation efficiencies exceeding 99.5 % for non-emulsified mixtures (oil:water = 1:1) and over 99.7 % for hydrocarbon oil/water emulsions (oil:water = 99:1). Furthermore, the membrane demonstrated remarkable stability, enduring multiple filtration cycles and harsh chemical environments, including extended exposure to NaOH solutions. To validate its industrial applicability, the nanofibrous membrane was employed in a membrane extraction process post amide synthesis, successfully separating dichloromethane and water, thereby streamlining the extraction process. This work showcases a robust membrane surface engineering strategy for efficient oil-water separation.