THE INFLUENCE OF CLASSICAL AND ENZYMATIC TREATMENT ON THE SURFACE-CHARGE OF CELLULOSE FIBERS

Natural cellulose fibres comprise several non-cellulose compounds and cationic trash which cause problems during different adsorption proces ses such as dying, printing, final fiber finishing and coating. Theref ore the pre-treatment (classical NaOH or environmental friendly enzyma tic treatment, demineralisation) is the most important step in cellulo se textile prefinishing - cleaning. An appropriate way to describe the success of different processes in fiber pretreatment which result in distinct surface charge is the determination of electrokinetic propert ies - zetapotential(ZP) of fibers and textile materials. The zetapoten tial was determined by streaming potential measurements as a function of the pH and the surfactant concentration in the liquid phase. Cellul ose fibers in an aqueous medium are negatively charged due to their ch aracteristic carbonyl and hydroxyl groups. The degradation and removal of specific hydrophobic non-cellulose compounds which cover the prima ry wall of the cellulose polymer change the surface charge. The ZP is mainly influenced by waxes, their removal decreases the negative ZP. T his result is obtained by the classical chemical process as well as by an environmentally friendly enzymatic treatment. Our results indicate that the progress of textile treatment and purification is reflected by the zetapotential of the fabrics. This method enables the estimatio n of the process'es progress and the interaction between components of the liquid phase and the fibre surface.