Preparation and characterization of anti-fouling β-cyclodextrin/polyester thin film nanofiltration composite membrane

Novel β-cyclodextrin (β-CD)/polyester thin film nanofiltration composite membranes were prepared via in situ interfacial polymerization of trimesoyl chloride (TMC) and triethanolamine (TEOA) in the presence of β-CD. The effects of the concentration and pendant group of β-CD on the separation, morphology and anti-fouling performance of NF composite membrane were investigated. The results show that introducing an appropriate amount of β-CD into membrane effectively improves the membrane performance. When the concentration of β-CD is 1.8% (w/v) in the aqueous phase, the water flux of NF composite membrane reaches a value which is almost two times that of the bare polyester membrane, while maintaining the rejection to Na2SO4 at a relative high level. The NF composite membrane exhibits a remarkable increase in the negative charge density and salt rejection by the incorporation of sulfated β-CD (sβ-CD) which possesses sulfonic acid groups as pendant groups instead of hydroxyls. Furthermore, the β-CD/polyester NF composite membrane also presents a significant enhancement in the anti-fouling performance. Therefore, β-CD can be considered as a potential additive to improve the property of nanofiltration composite membrane.