Reduced Transport Numbers of PolysulfoneMembranes From The Initial Time EMF Measurements

Abstract

Initial membrane potentials of polysulfone cation exchange membranes were measured with KCl, NaCl, LiCl CaCl2 and FeCl3 solutions by using Ag/AgCl electrodes. The measurements were carried out for KCl / unsupported polysulfone cation exchange membranes (SA3S) or polyester supported polysulfone cation exchange membranes ( SA3T) / KCl, NaCI, LiCI, CaCl2 and FeCl3 systems. The concentration of KCl, C1, was kept constant at 1.10-2 M in one cell; however the concentrations of KCl, NaCI, LiCl, CaCl2 and FeCl3, C2, in the other cell were changed from 1.10-4 M to 2.0 M. The Supported face of SA3T membrane was brought to equilubrium with the left- hand solution and then, the unsupported face of SA3T membrane was exposed to the right-hand solution. Transport number of K+, Na+, Li+, Ca+2, Fe+3 ions corresponding to the each of two surface layers of the membrane was evaluated from the initial time and  the fifth minute emf measurements. The results were compared with between unsupported polysulfone cation exchange membranes and polyester supported polysulfone cation exchange membranes.

Keywords

• The mean reduced transport number
• mean
• Initial time
• Cation exchange membrane

References

1. Y.Yamada, C.H. Witter, M.J. Bukovoc, Penetration of ions through isolated cuticles, Plant Physiol. 39 ( 1964) 29-32.
2. T.S. Sorensen, J.B. Jensen, B. Malgren-Hansen, Electrochemical characterization of cellulose acetate membranes.1. Influence of hydrogen and calcium ions on the emf of LiCl concentration cells with a CA-membrane as separator, J. Non- Eq. Therm. 13 (1988) 57-79.
3. T.S. Sorensen, V. Compan, Salt flux and electromotive force in concentrations cells with asymmetric ion exchange membranes and ideal :1 electrolytes, J.Phys. Chem. 100 (1996) 15273.
4. J. Garrido,V. Compan, Asymmetry potential inhomogeneous membranes, J. Phys. Chem. 96 (1992) 2721-2724
5. V. Compan,M.L Lopez, T.S. Sorensen, J. Garrido Transport numbers in the surface layers of asymmetric membranes from initial time measurements, J. Phys. Chem. 98 (1994) 9013
6. T.S. Sorensen, V. Compan, S.R. Rivera, comparison of initial time and stationary state measurements of the emf concentration cells using phenolsulfonic acid membrane seperators, J Phys. Chem. 99(1995) 12553-12558.
7. T.S. Sorensen, V. Compan, Nernst-Planck model simulating the electromotive force measured over asymmetric membranes with special reference to the initial time method for investigation of surface layers, J. Phys. Chem. (1996) 7623-7631.
8. M.Ersöz,Transport numbers in biomembranes from emf measurement. Biophsical Chemistry (2001) 237-243.

9. M. Ersöz, permeability of Biomembranes In: Encyclopedia of Surface and colloid Sicience, Ed. Arthur Hubbard, marcel Deccer(2001).
10. M. Ersöz, H.J. Duncan, Permeability of periderm and cuticular membranes to alkali cations,J Coll. İnter. Sci.169(1995) 143-148.
11. Haredia J. Benavente, A study of membrane potential across isolated fruit cuticles for NaCl and CaCl solutions, biochem. Biophs. Acta 1062 (1991) 239-244. J. Benavente, A.Munoz,
12. Electrokinetic paramaters of ion transport across isolated paper cuticular membranes, J. Membr. Sici. 139(1998)147-154. Haredia,
13. V. Compan, T.S. Sorensen, A. Andreo, L Lopez, J. De Abajo, Transport numbers from initial measurements of the emf in non-ionic polysulfonic membranes, J. Membr. Sci. (1997) 293-302. stationary state