Ligninsulfonate/trimesoylchloride nanocomposite membrane with transmembrane nanochannels via bionic cell membrane for molecular separation

Separation membrane with high permeance was constructed via a facile in situ silver nanoparticle (AgNP) introduction technology: (1) the AgNPs were in situ formed and stabilized in aqueous phase by adding ligninsulfonate (SLS) to AgNO₃ aqueous solution; (2) the thin-film nanocomposite (TFN) membrane with uniform distribution of AgNPs in the active layer (TFN-Ag membrane) was fabricated through the interfacial polymerization between SLS aqueous phase in which AgNPs were introduced and trimesoyl chloride (TMC) organic phase. The uniform and stable dispersion of AgNPs in the SLS aqueous phase enabled the uniform distribution of AgNPs in the active layer of the TFN-Ag membrane, endowing the membrane with transmembrane nanochannels, similar to nanochannels of cell membrane for mass transfer. The hydrophilicity of the fabricated membrane was also enhanced. In addition, the TFN-Ag membrane exhibited a highly negatively charged surface at pH 3–10. Therefore, the TFN-Ag membrane exhibited a high permeance of 41.7 L m⁻² h⁻¹ bar⁻¹ with 99.8% rejection rate of Congo red (CR), excellent flux recovery ratio of 99.2%, and stable separation performance in salt, acid, and alkali environments for CR removal. The excellent separation performance indicated that the fabricated membrane has significance in separation processes.