Electrochemical study of the interfacial behaviour of cationic polyelectrolytes and their complexation with monovalent anionic surfactants

J. RIVA; K. BIERBRAUER; D. BELTRAMO; M. YUDI

ELECTROCHIMICA ACTA

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2012 vol. 85 p. 659 - 664

0013-4686

The complexation of two hydroxyethylcellulose, of different molecular weights, SC 230 and SC 240, with the anionic surfactants perfluorodecanoic acid, PFDA, and perfluorooctanoic acid, PFOA, has been studied. For this purpose, the anions transfer current across a water/ 1,2 ? dichloroethane interface was employed to quantify anions concentration in the absence or in the presence of polyelectrolyte. When polymers were added in increasing amounts to solutions containing PFDA or PFOA, a gradual decrease in current values was observed, evincing the binding of the anions to the polymer. Transfer Current of the anions, was used for the construction of binding isotherms, which were fitted by Satake and Yang theory. Cooperative binding was observed, but all fluorinated acids gave a similar cooperativity parameter, and it was found that both the overall constant as well as the cooperative binding process, increases with the molecular weight of the polymer.