Abstract
The ζ-potential of synthetic fibers, polyacrylonitrile (Cashimilon), polyester (Tetoron), polypropylene (Pylen), polyvinylalcohol (Vinylon) and polyamide (Nylon 6), was measured in surface active went (anionic agents SDS and cationic agent DPB) solutions at neutrality and at alkalinity. The charge density and the amount of surface active agents adsorbed per unit area of the fiber surface were calculated from the ζ-potential of the fibers.
From the effect of the concentration of surface active agent on the ζ-potential, it is suggested that the adsorption of anionic agent SDS on these fibers takes place mainly by the van der Waals' force, but the adsorption of cationic agent DPB on these fibers takes place mainly by the electrostatic attractive force.
The amount of surface active agent adsorbed per unit area of the fiber surface increased with the increase of the concentration of those agents, and the greater the increase was, the more hydrophobic the fiber in the order of polyvinylalcohol, polyaerylonitrile, polyamide, polyester and polypropylene.
Also the amount of SDS adsorbed per unit area of the fiber surface in aqueous neutral solution was greater than that in aqueous alkali solution, but the amount of DPB adsorbed per unit area of the fiber surface in aqueous alkali solution was greater than that in aqueous neutral solution.
