(666g) High-Perfromance Nanofiltration Hollow Fiber Membranes for Wastewater Treatment

Due to the well-defined pore size (i.e., 0.5−2.0 nm in diameter) and rationally designed surface charge characteristics, nanofiltration (NF) membranes can effectively remove a variety of inorganic and organic contaminants from wastewater. In order to simplify the fabrication process of conventional polyamide thin film composite (TFC) NF membranes and leverage the advantages of hollow fiber configurations, NF hollow fiber membranes with ultrahigh water permeability and well-defined nanopores and surface charge characteristics were developed via a single-step spinning process. The as-spun NF hollow fiber possesses a high pure water permeability (PWP) of 80 L·m^−2·h^−1·bar^−1 with a small pore size of 1.0 nm in diameter and a MWCO of 1000 Da. Surface modification by hyperbranched polyethylenimine (PEI) can further lower the pore diameter to 0.85 nm and MWCO to 680 Da. In addition, the NF hollow fibers exhibit outstanding performance stability, low fouling tendency, and great fouling reversibility in textile wastewater treatment. This study provides important insights for the design and fabrication of wholly integral asymmetric hollow fiber NF membranes with ultrahigh flux and good rejection for wastewater treatment and water purification.