Can the NF membrane directly obtained by the interfacial polymerization of MPD and TMC?

In the practical application of nanofiltration (NF) membrane, regular chemical cleaning is necessary to eliminate the membrane fouling and ensure the normal operation of the system. Generally, the commercial NF membranes can be divided into MPD-TMC membranes and PIP-TMC membranes of which the permeability and pH resistance cannot be balanced. In this work, the ultra-low concentration monomers of MPD and TMC were used to fabricate the dense polyamide layer of NF membrane through a conventional interfacial polymerization reaction. The newly prepared membrane exhibited a smooth surface with very low roughness. Besides, the pore size distribution and desalination performance including water permeability and salt rejection of our membrane were comparable to the lab-made and commercial PIP-TMC membranes. The membrane was also confirmed to have an excellent separation efficiency to SO42−/Cl− anions and good resistance to extreme pH conditions. Overall, this study presents a new insight for the preparation of high-performance NF membrane with good chemical stability.