LOOSE ULTRAFILTRATION OF PROTEINS USING HYDROLYZED POLYACRYLONITRILE HOLLOW-FIBER

Ultrafiltration of proteins using hydrolyzed polyacrylonitrile hollow fiber was investigated in this work, Polyacrylonitrile hollow fiber wa s spun and hydrolyzed with NaOH aqueous solution under various conditi ons. A thin layer of polyacrylic acid was formed on the inner surface of the hollow fiber, and the ionic density on the hydrolyzed surface w as determined through titration. The hydrolyzed hollow fiber was chara cterized with the hydraulic permeability and the retention of dextran. A sharp decrease in the hydraulic permeability was observed between p H 5 and 6, possibly due to the swelling of the hydrolyzed layer. The r etention of dextran slightly increased with the ionic density of the h ydrolyzed hollow fiber. The retentions of two proteins, myoglobin and cytochrome c, were measured over a range of pH values (4 similar to 10 ). The results show that the retention of protein changes with pH, and is the lowest at the isoelectric point. Separation of mixtures of cyt ochrome c and myoglobin was performed at pH 5, 7, and 9 using hydrolyz ed PAN hollow fiber. The selectivity of the cytochrome c over myoglobi n was about 40 at pH 5, about 1 at pH 7, and about 0.5 at pH 9.