Preparation of self-healing and pH-responsive nanofiltration membranes with improved anti-fouling property for salt/dye separation

Nanofiltration (NF) membranes can inevitably suffer from external damage in the practical application process, causing the loss of their original function and performances. In this work, the β-CD-D X -S were synthesized for the first time through one-step polymerization of SBMA, DMAEMA and double bond functionalized β-CD. Subsequently, the membrane was successfully fabricated via interfacial polymerization using the constructed β-CD-D X -S as aqueous phase monomer alone. The prepared β-CD-D X -S/PES membrane exhibits novel self-healing performance attributing to the host-guest interaction between DMAEMA and β-CD. The membranes also possess excellent pH-responsive property attributing to the protonation and deprotonation behavior under different pH environments of dimethylamine unit in DMAEMA. The grafted DMAEMA and SBMA enhanced the hydrophilic property of membrane, reducing electrostatic adsorption of pollutants on the surface of membrane. The hydrophobic binding site inside the cavity of β-CD can accommodate dimethylamino group in the DMAEMA which could be regulate the spatial structure of β-CD-based materials, strengthening salt/dye selectivity of membrane. The results indicated that the prepared β-CD-D X -S/PES membranes possess good potential for NF applications.