Highly chlorine-resistant end-group crosslinked sulfonated-fluorinated poly(arylene ether) for reverse osmosis membrane

Building bridges: Crosslinking of sulfonated aromatic polymers—A review

“…In fact, this does not occur as expected. For example, some SAP membranes for PEMFC applications were synthesized via direct polymerization from monomers containing olefinic bonds [81][82][83][84][85] or alkyne bonds [86][87][88][89][90][91][92]. The subsequent UV-light-induced XL reactions were performed under the activation of a photo-initiator, which is a key factor for achieving fast and extensive crosslinking.…”

Chlorination disadvantages and alternative routes for biofouling control in reverse osmosis desalination

“…36 Moreover, they can be used only in the pH range between 3.5 and 6.5 and being organically derived make them more vulnerable to microbial attacks. 37 Additionally, hydrolysis and oxidation degradation phenomena slowly impair their performance, as the first phenomenon causes a conversion of the polymer acetyl groups into hydroxyl groups over time, reducing the ability of the membrane to retain salt. 38 The most commonly used RO membranes in the desalination industry are made of multi-layered PA thin film composites (TFC), based on a thin cross-linked polyamide layer less than 0.2 µm thick, offering higher water flux, good chemical stability, and requiring a lower operating pressure differential.…”

“…Such membranes are built as in ref. 37 and studied for varying sulfonation amount, showing high resistance to chlorine, with however a significant drawback of salt retention percentage between 75% and 98%, too low for industrial applications as onepass desalination membranes. PA membranes based on 17 different diamine compounds (aromatic, aliphatic, cycloaliphatic and heterocyclic) and isophthaloyl dichloride (IPC) or 1,3,5benzenetricarbonyl trichloride (TMC) were fabricated as per ref.…”

Degradation of Polymer & Elastomer Exposed to Chlorinated Water—A Review

“…Recent studies on membrane stated that Crosslinked (C-ESFx-BP) and non-crosslinked (N-ESFx-BP) sulfonated poly(arylene ether) (SPAE) membranes displayed the long-term stability longer than 30 days during the operation condition under high acidic chlorine concentration of NaOCl 4000 ppm unlike commercial PA membranes which are unstable under the chlorine treatment [95]. The polyimide thin film composite, reverse osmosis membranes prepared from MPD [m-phenylene diamine], BTC [1,2,4,5-benzene tetracarbonyl chloride] and TMC [trimesoyl chloride] showed significantly enhanced chlorine resistance due to the elimination of chlorine-sensitive sites by the replacement of amide linkage with imide linkage [96].…”