Adsorption of Cationic SA on Polyester Fiber Surface and its Influence on the Electrokinetic Potential

Resumo

Results

from a study of the adsorption of the cationic surfactant (SA) catamine AB from aqueous solutions onto the surface of polyester fibers are reported. It was found that a bimolecular layer was formed after adsorption of this SA. The SA molecules in the first adsorbed layer reacted with polyester polar groups to form an interpolymer complex. A specific adsorption potential, i.e., intermolecular interaction of SA hydrocarbon groups with fiber hydrophobic sections, was also apparent. The second adsorption layer was formed exclusively via reaction of hydrocarbon radicals of the first and second adsorbed layers. The effect of catamine-AB adsorption on the polyester-fiber electrokinetic surface potential was investigated. It was found that the negative electrokinetic potential decreased as the adsorbed SA layer formed on the fiber surface. The isoelectric surface state was observed at a catamine concentration of ~5·10^–2 g/L, after which the fiber became overcharged. This indicated that the SA adsorbed to form a bilayer structure.