Zeta potential of hollow fiber dialysis membranes and its effects on hydrogen phosphate ion permeability.
To clarify ion transport, dialysis membranes are evaluated in terms of zeta potential calculated by the Helmholtz-Smoluchowski equation from data on streaming potential delta E and pressure drop delta P, depending upon the operating conditions at which the values are measured. The objective of the current study is to design an improved method for measurement of delta E and delta P of hollow fiber dialysis membranes and to clarify the diffusive permeability of hydrogen phosphate ion. A polytetrafluoroethylene cylindrical cell with an inside diameter of 14 mm and a height of 10 mm was packed with 2,000-3,000 pieces of hollow fibers, and glass filters were set on either side of the cell. Deaerated water purified by ion exchange and reverse osmosis with an electric conductivity of approximately 150 microS/m was caused to flow in the hollows at 293 K to determine delta E and delta P. A good linear relationship between delta E and delta P and the reproducibility of the data was obtained and is shown in Figures 5 and 6, demonstrating the utility of the improved method to measure delta E and delta P, and the validity of the Helmholtz-Smoluchowski equation to calculate zeta potential from data on delta E and delta P. Hydrogen phosphate ion permeability increased with zeta potential for the membranes at about the same rate as pure water permeability. This indicates that hydrogen phosphate ion permeability depends upon the charge and internal structure of dialysis membranes.
Suzuki
Y
Y
Department of Chemical Engineering, Waseda University, Tokyo, Japan.
Kanamori
T
T
Sakai
K
K
D015314:Dialysis Solutions; D004058:Diffusion; D006801:Humans; D007688:Kidneys, Artificial; D008567:Membranes, Artificial; D010710:Phosphates
D015314:Dialysis Solutions; D008567:Membranes, Artificial; D010710:Phosphates