Effects of Glassy Polymers as Active Layer of Polyethersulphone Membranes for Optimisation of Air Separation Process at Low Pressures

Three kinds of composite membranes based Polyethersulphone (PES) were prepared via coating procedure for oxygen enrichment process at low pressures. Different concentration of glassy polymers (1, 2 and 6%wt) include Ethyl cellulose (EC), Poly vinyl alcohol (PVA) and Polystyrene (PS) were employed for active layer preparation on the PES support membrane (18%wt PES). Performance results showed that EC composite membranes did not have any selectivity but PVA and PS have changed the selectivity of PES membranes to some extent. For enhancement of the EC composite membrane selectivity the composition of support and active layer solution were increased separately (9-wt% for EC in coating solution and 25 and 37- wt% for PES in support solution). Gas permeability and selectivity of EC membranes revealed that coating solution with EC concentration of 6%wt on the PES membrane with concentration of 25-wt% is an optimum state for enhancing the selectivity. For proving the structural changes in composite membranes, some morphological analyzes using scanning electron microscopy and IR-ATR experiments were performed.

کلیدواژه ها:

membrane structure ، morphology ، gas separation ، phase inversion