Polybenzimidazole Membranes for Organic Solvent Nanofiltration Applications in Extreme pH

摘要

Many pharmaceutical and chemical processes require separations at different stages of their production. Industrial applications often involve separation between dissolved molecules in the range of 200 - 2000 g.mol~(-1). Membrane nanofiltration (NF) can provide the necessary discrimination between solutes in this range. Development of polymeric NF membranes has started in the early 1970s and since then membranes have been widely applied to processes in aqueous environments e.g. in food production and water softening [1]. The lack of solvent stable polymer materials has so far limited the use of NF in non-aqueous environments. However, organic solvent nanofiltration (OSN) has gained interest in recent years and much research has been carried out to improve chemical resistance of membrane materials. Although much progress has been made to improve OSN technology [2], current membranes still face several issues in OSN - low discrimination between target molecules and waste reagents, poor chemical stability especially in basic/acidic environments and poor consistency over service life time.