On Blend CA/PAN Ultraflltration Membrane

The CA/PAN blend ultrafiltration membrane is studied. Some preparative methods for making a blend membrane with cut-off molecular weight 67 000 a found: ① Use (DMF+LiCl): DMAC=1.5:1.0 as blend solvent, with polymer concentration 16%. ② Apply acetone, benzol and formamine as secondary additives, with polymer concentration 14%. ③ Use aqueous solution which contains some inorganic salt or organic solvent (e.g. CaBr₂, alcohol, DMF or DMAC) as gelating medium, with ploymer concentration 18%. In these methods, addition of secondary additives is the most effective.