Graft modification of polybenzimidazole membranes for organic solvent ultrafiltration with scale up to spiral wound modules

In this work the selectivity of crosslinked organic solvent stable PBI membranes is tuned by varying molar ratio two grafting agents: a long flexible polymer modifier (Elastamine RE-1-1000, 1000 g mol-1) and small molecule (2-methoxyethylamine, 75 mol-1). Grafting exclusively with chain provided membrane molecular weight cut-off (MWCO) 2000 mol-1 in acetonitrile. Increasing proportion reaction capped sites membrane. This caused decrease density allowed for MWCO to be customised between 20,000 High densities underlie control performance, up 43% increase specific during modification. technique was scaled manufacture 5 m lengths that were incorporated into 1.8″ x 12” spiral wound modules, which showed performance consistent flat sheet membranes.