In this work we show from comparison between experimental and theoretical conductibilities of Sodium Heparin in aqueous dilute solutions according to the ellipsoidal model, that for long chain (Heparin RB21055, LS = 160 A°, ZS = -55), the transition from stretched to coiled configuration occurs progressively with the increase of the Na+ concentration due to the ionic condensation and the screen effect. In contrast, for relatively short chain (Heparin H5027 and H5271, LS = 64 A°, ZS = -22) all the configurations are equivalent. In particular, the polyion could be assimilated to a charged sphere with a radius of about 17 A°.
A. Ghazouani, S. Boughammoura, J. M’halla
héparine, conductibilité, condensation ionique, élecrophorétique, relaxation ionique, friction diélectrique, conformation, ellipsoïdale