The sorption of N-cetylpyridinium chloride on Leacril fibers. Electrokinetic properties

An experimental investigation on the streaming potential and sorption of N-cetylpyridinium chloride on Leacril fibers has been carried out. The results reveal that the uptake of N-cetylpyridinium chloride on Leacril fibers takes place by means of electrostatic attraction between the cation of the surface-active agent used and both the sulphonate and the sulfate end-groups of the Leacril. Given the hydrophobic character of Leacril and the amphiphilic nature of the N-cetylpyridinium chloride molecules, hydrophobic attractions between the fiber and the hydrophobic part of the surfactant might account for the interaction, explaining the sorption of N-cetylpyridinium chloride even when it is hindered by electrostatic repulsion. The electrical characterization of Leacril fibers has been carried out and the methods employed for the determination of zeta potentials of Leacril fibers are discussed, on the basis of streaming potential technique. In our case for this hydrophobic fiber, the linear model of Goring and Mason of a bundle of capillaries gives the most precise values of zeta potential. Also discussed is the behavior of the surface conductance of the system in the above process of sorption.