| Abstract: | Electrokinetic properties of methacrylic acid- and acrylonitrile-grafted polypropylene fibers measured in the presence of cationic dyes are reported. The zeta potential of polypropylene fibers decreases, and the surface charge density along with surface conductivity increases as the concentration of the dyes in the streaming solution increases. The zeta potential at pH 7 decreases as the amount of graft increases in case of both acrylonitrile- and methacrylic acid grafted fibers. Both surface charge density and surface conductivity increase with the increase in dye concentration for both acrylonitrile- and methacrylic acid-grafted fibers. The results are explained on the basis of the cationic dye adsorption on the grafted fiber in the case of methacrylic acid graft. In the case of acrylonitrile-grafted fibers, this could be due to the strong attraction of cationic dye to the nitrile group of the grafted fibers. |
