Electrokinetic Property of Modified Polyacrylonitrile Membranes in the Haemodialysis

Experimental investigations of electrokinetic property of modified polyacrylonitrile membranes in the haemodialysis were performed using the streaming potential method. The zeta potentials of the membranes in the blood were estimated on the basis of Helmholtz-Smoluchowski equation. The experimental and calculation results show that the membranes are charged negatively, whose zeta potentials maintain at -20 mV around. And the aperture of membranes, the temperature and the filtration flux have little influence on the streaming potentials and the zeta potentials of the membranes . Also the suspended particulates in the sanguine molecular substance are charged negatively. The membranes have strong ability withholding the molecular substance and powerful antipollution competence because of the role of the charges on the membranes.