Kumano, Atsuo, et al. Solvent Extraction Research and Development, 2012, 19, 89-99.
A composite nanofiltration hollow fiber membrane was created using perfluorotripentylamine as a solvent. This membrane featured a thin polyamide layer on its outer surface, formed through a unique interfacial polymerization technique. The characteristic of this process is that by using a third liquid (perfluorotripentylamine) that is neither miscible with nor miscible with amine aqueous solution, interfacial polymerization occurs only on the outer surface of the hollow fiber.
Preparation of composite hollow fiber membranes
· First, a microporous hollow fiber support membrane was prepared using polysulfone, polyethylene glycol (average molecular weight 600), sodium dodecylbenzenesulfonate and dimethylacetamide.
· The hollow fiber support membrane was first submerged in the amine aqueous solution, followed by passing through air and finally through the inert liquid fluorocarbon perfluorotripentylamine. The amine aqueous solution comprises of 2wt% piperazine, 0.5wt% triethylenediamine, and 0.1wt% sodium dodecylsulfonate. Meanwhile, the n-hexane solution includes 1wt% TMC.
· Subsequently, the membrane was passed through the n-hexane/TMC solution to initiate an interfacial reaction. These procedures were carried out at a coating speed of 1 m/min, at room temperature (approximately 25°C), resulting in the formation of a continuous composite hollow fiber membrane.
· The composite hollow fiber membrane then underwent a drying process in a chamber set at 50°C before being immersed in a water washing bath at 25°C.
Zhang, Hong, et al. Journal of the American Chemical Society, 2020, 132(50), 17867-17879.