Second Interfacial Polymerization of Thin-film Composite Hollow Fibers
with Amine-CDs for Pervaporation Dehydration
Abstract
High performance thin-film composite (TFC) hollow fiber membranes have
been developed for pervaporation dehydration by second interfacial
polymerization (SIP) modification with 3 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 ultra-high
permeation flux (3018.0±12.0 g/m2.h) 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.