Studies on nanofiltration membrane formed by diisocyanate cross-linking of quaternized chitosan on poly(acrylonitrile) (PAN) support

Positively charged aromatic polyamide reverse osmosis membrane with high anti-fouling property prepared by polyethylenimine grafting

“…permselectivity) intact, especially in the adjustment of the NF membrane surface charge [5,7,10,13,14]. For example, grafting or coating with pendant tertiary amine groups [7] and quaternary ammonium salt [5] on NF membrane surfaces usually succeeded in the obtaining of positively charged membranes.…”

Anti-scaling ultrafiltration/microfiltration (UF/MF) polyvinylidene fluoride (PVDF) membranes with positive surface charges for Ca2+/silica-rich wastewater treatment

“…Thus, in terms of membrane materials, it is necessary to introduce an anti-adhesive force on the surface of membrane to repel metal ions and precipitates. In an attempt to solve membrane scaling, positively charged membranes synthesized by introducing cationic materials to the membrane were recently reported [16][17][18][19][20]. Cheng et al prepared a positively charged nanofiltration (NF) membrane by crosslinking positively charged polyethylene imine (PEI) on the surface [21].…”

Positively charged nanofiltration membrane based on cardo poly(arylene ether sulfone) with pendant tertiary amine groups

“…Positively charged NF membranes can be prepared by coating a positively charged separation layer to a supporting membrane [11][12][13] or induce positive charge to an existing membrane surface by chemical reactions [9,14]. These methods often involve multi steps, thus are uneconomic.…”