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Novel polyamide thin film composite (TFC) nanofiltration (NF) membranes were prepared on polyetherimide supports by the interfacial polymerization of 1,2,4,5-benzene tetracarbonyl chloride and m-phenylenediamine followed by modification with ethylenediamine (EDA). The TFC NF membranes thus prepared were characterized by attenuated total reflection Fourier transform infrared (ATR-FTIR), solid-state nuclear magnetic resonance (NMR) and X-ray photoelectron spectroscopy (XPS); these results indicated that by covalent bonding with EDA, the unstable carboxylic groups on the initially generated poly(amic acid) (PAA) TFC membrane surfaces were effectively transformed into polyamide, including the methylene group in the chemical structure chain, for preparing the PAA-cov-EDA NF membranes. At an operating pressure of 1.0 MPa, the PAA-cov-EDA NF membrane exhibits a glucose rejection of 90% at a flux of 25 L m−2 h−1, and a MgSO4 rejection of 76% at a flux of 31 L m−2 h−1, in particular demonstrating its superior chlorine resistance, after being immersed in a 200 ppm NaClO solution for 100 h. Such novel polyamide TFC NF membranes have the advantages of mild preparation conditions and high rejection towards low-molecular-weight organics, thus demonstrating their potential in the pharmaceutical industry. [ABSTRACT FROM AUTHOR]

Sulfonated polysulfone (SPSF) with different sulfonation degrees (10%, 30%, and 50%) was added to polyethersulfone (PES) to improve the separation and antifouling performance of polyethersulfone ultrafiltration membranes. The PES/SPSF blend ultrafiltration membrane was prepared by the non-solvent induced phase inversion method (NIPS), and the effect of sulfonation degree on the ultrafiltration performance was studied. The compatibility of SPSF and PES was calculated by the group contribution method, and confirmed by differential scanning calorimetry (DSC). The morphology and surface roughness of the membrane were characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM), the chemical composition of the membrane was analyzed by X-ray photoelectron spectroscopy (XPS) and infrared spectroscopy (FTIR), and the permeability and anti-fouling performance of the blend membrane were studied through filtration experiments. The research shows that the flux and anti-fouling performance of the blend membrane have been improved after adding SPSF. When the sulfonation degree of the SPSF is 30%, the pure water flux of the blend membrane can reach 530 L m -2 h -1 , the rejection rate of humic acid (HA) is 93%, the flux recovery rate of HA increases from 69.23% to 79.17%, and the flux recovery rate of BSA increases from 72.56% to 83%., Competing Interests: On behalf of my co-authors, we declare that we have no conflicts of interest to this work. We do not have any commercial or associative interest that represents a conflict of interest in connection with the work., (This journal is © The Royal Society of Chemistry.)

The hydrophobicity of ultrafiltration membranes is the main cause of membrane fouling and reduced permeability, so it is necessary to improve the hydrophilicity and anti-fouling performance of ultrafiltration membrane materials. MoS 2 nanoparticles that were modified with polydopamine (PDA) and polyethyleneimine (PEI), named MoS 2 -PDA-PEI, were added to fabricate a polyethersulfone ultrafiltration membrane (PES/MoS 2 -PDA-PEI) for the first time. The effects of modified MoS 2 nanoparticles on membrane performance were clarified. The results indicated that the permeability, rejection, and anti-fouling capability of the hybrid PES/MoS 2 -PDA-PEI membrane have been improved compared with the pristine PES membrane. When the content of MoS 2 -PDA-PEI nanoparticles in the membrane is 0.5%, the pure water flux of the hybrid membrane reaches 364.03 L m -2 h -1 , and the rejection rate of bovine serum albumin (BSA) and humic acid (HA) is 96.5% and 93.2% respectively. The flux recovery rate of HA reached 97.06%. As expected, the addition of MoS 2 -PDA-PEI nanoparticles promotes the formation of the porous structure and improves the hydrophilicity of the membrane, thereby improving its antifouling performance., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)