Incorporating of β-cyclodextrin based nanosheet for advanced thin-film nanocomposite nanofiltration membrane with improved separation and anti-fouling performances

Nanotechnology has created numerous opportunities for the development of novel thin film nanocomposite (TFN) membranes. In this study, we prepared a novel β-cyclodextrin based nanosheets (β-CDNSs) with a lateral size of approximately 200–400 nm and thickness of ∼10 nm through the interfacial polymerization method and used it as the nanofillers in aqueous phase to prepare advanced nanofiltration (NF) membranes. The high microporosity, organic attribute, hydrophilic COOH and reactive OH groups present in β-CDNSs are conducive to the microstructural parameters fine-tuning of the resultant TFN membranes. The optimal membrane TFN-0.02 presented the PA selective layer with thinner thickness, less crosslinking degrees, prominent globule microstructures, and increased hydrophilic properties. As a result, it achieved a remarkable enhancement in pure water permeability (21.46 L m− 2 h− 1 bar− 1, versus 8.79 L m− 2 h− 1 bar− 1, nearly 2.4-fold increase), high rejection of divalent salt (above 98% for Na2SO4) and an outstanding selectivity of αNaCl/Na2SO4 = 50.27. Moreover, the tailored membrane TFN-0.02 exhibited superior resistance towards four typical organic foulants BSA, LYZ, DTAB and SDS. Overall, this work provides insightful guidance for the design of novel organic nanomaterials with desired properties for greatly enhanced separation performances of as-fabricated membranes.