Second interfacial polymerization of thin-film composite hollow fibers with amine-cyclodextrins for pervaporation dehydration

High performance thin-film composite (TFC) hollow fiber membranes have been developed for pervaporation dehydration by second interfacial polymerization (SIP) modification with three kinds of amine-functionalized β -cyclodextrin (amine-CDs), which were synthesized by modifying β -CD with ammonia, ethylenediamine (EDA), and tris(2-aminoethyl)amine, respectively. The chemical properties of amine-CDs and SIP-modified TFC membranes were characterized by various techniques. The effects of amine-CD type and SIP parameters (pH or concentration of CD-EDA solution) were studied systematically to acquire the optimized selective layer of TFC membranes for ethanol dehydration. Among all SIP-modified TFC membranes, the one with SIP by 2 wt% CD-EDA aqueous solution (pH = 2) exhibited the most outstanding separation performance with a ultrahigh permeation flux (3,018.0 ± 12.0 g/m 2 hr) and permeate concentration (98.7 ± 0.2 wt% water) at 50°C (equivalent to separation factor of 415), contributed by the effectively incorporated CD with rich hydrophilic functional groups and intrinsic nanocavities facilitating the passage of water molecules.