DETERMINATION OF THE PORE-SIZE DISTRIBUTION OF MEMBRANES BY GEL-PERMEATION CHROMATOGRAPHY

Polyacrylonitrile membranes with different separation ranges are prepa red and characterized by gel permeation chromatography. The determinat ion of the pore size distribution of the ultrafiltration flat membrane (upper ultrafiltration range) and of the microfiltration hollow fiber membrane (lower microfiltration range) is affected by different measu ring procedures. A comparison of the parameters of separation performa nce is obtained by making use of aqueous poly(ethylene glycol) (PEG) m ixtures with broad molecular weight distribution, or the application o f single PEG test substances is performed. The obtained results are di scussed in connection with the separation range of membranes and the m olecular weight of test solutions.