engleski

ELECTROKINETIC PHENOMENA OF TEXTILE FIBERS

Electrokinetic phenomena are crucial for textile dyeing and finishing processes. These interface phenomena have influence on adsorption of surfactants, optical brighteners, dyes and finishing agents due to interaction forces between fiber surface and solutions. The electrokinetic (zeta, ζ ) potential is part of the total potential drop occurring in the intermediate surface layer at the boundary of the solid/liquid phases as a consequence of the ions distribution from the solid surface to the liquid mass. At the interface of an electrically charged textile fibers and an aqueous solution of electrolyte, surfactants or dyes an electric double layer is setting up. Moving one of these two charged surfaces results by electrokinetic (zeta) potential. Zeta potential gives information about nature and dissociation of functional groups, hydrophilicity or hydrophobicity of fiber surface as well as ions or water sorption. In general, specific adsorption of ions or dissociation of the surface groups in aqueous solution results with their surface charge. Fiber surface charge depends upon their molecular and supramolecular structure, swelling capacity as well as upon ionogenity, structure and concentration of adsorbate. The wet treatments change the fiber surface charge, zeta potential and adsorption ability as well. Therefore, this paper reports electrokinetic phenomena in water solution of textile fibers commonly used in textile and clothing industry. The electrokinetic (zeta) potential, Isoelectric Point (IEP), Point of Zero Charge (PZC) and specific quantity of surface charge (q) of Cotton, Wool, Polyamide 6.6 (PA), Polyester (PET) and Polypropylene (PP) in the present work has been determined using the special techniques. Zeta potential was measured by streaming potential/current method using a Brookhaven-Paar electrokinetic analyzer (EKA), with a circular cell designed for textile fibers. Specific quantity of surface charge was calculated after back-titration method, applying Mütek’ s Particle Charge Detector (PCD 02). These phenomena characterize electrical charge of investigated textile fibers.

electrokinetc phenomena; zeta potential; textile fiber; surface charge

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