title: Chlorine-Resistant Polyamide Reverse Osmosis Membrane with Monitorable and Regenerative Sacrificial Layers.
abstract: Improving chlorine stability is a high priority for aromatic polyamide (PA) reverse osmosis (RO) membranes especially in long-term desalination. In this Research Article, PA RO membranes of sustainable chlorine resistance was synthesized. Glycylglycine (Gly) was grafted onto the membrane surface as a regenerative chlorine sacrificial layer, and the zeta-potential was used to monitor the membrane performance and to conduct timely regeneration operations for chlorinated Gly. The Gly-grafted PA membrane exhibited ameliorative chlorine resistance in which the N-H moiety of glycylglycine served as sacrificial pendants against chlorine attacks. Cyclic chlorination experiments, combined with FT-IR and XPS analysis, were carried out to characterize the membrane. Results indicated that the resulting N-halamines could be fast regenerated by a simple alkaline reduction step (pH 10). A synchronous relationship between the zeta-potential and the chlorination extent of the sacrificial layer was observed. This indicated that the zeta-potential can be used as an on-site sensor to conduct a timely regeneration operation. The intrinsic mechanism of the surface sacrificial process was also studied.
authors.affiliation: Key Laboratory of Biomass Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University , Hangzhou 310027, P. R. China.
authors.forename: Hai
authors.initials: H
authors.lastname: Huang
authors.affiliation: Key Laboratory of Biomass Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University , Hangzhou 310027, P. R. China.
authors.forename: Saisai
authors.initials: S
authors.lastname: Lin
authors.affiliation: Key Laboratory of Biomass Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University , Hangzhou 310027, P. R. China.
authors.forename: Lin
authors.identifier: http://orcid.org/0000-0002-1337-2538
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Biomass Chemical Engineering, College of Chemical and Biological Engineering, Zhejiang University , Hangzhou 310027, P. R. China.
authors.forename: Li'an
authors.initials: L
authors.lastname: Hou
keywords: chlorination; grafting membrane; regenerative membrane; reverse osmosis; zeta-potential