The significance of surface charge and structure on the accessibility of cellulose fibres

The electrokinetic properties of macroscopic solids can describe both the surface modifications as well as the interaction abilities during processing. Normally the zeta potential (ζ) is measured and can be used to develop, optimise and control the manufacturing process. The zeta potential of natural and regenerated cellulose fibres changes noticeably during the pre-treatment and finishing process and it is important for the quality of the final product (whiteness, colour, hydrophilicity). The pre-treatment of cellulose fibres improves the accessibility of dissociable groups. Further improvement of hydrophilicity (mercerisation) causes a pronounced increase in the surface charge density and a reduction in the degree of crystallinity and structural modifications. The progress of the chemical as well as the enzymatic treatment correlates with ζ. These data correlate very well with the results obtained using tensiometry, water retention, and water vapour and iodine adsorption. The changes in crystallinity index and the accessibility for low molecular components are well described by the latter methods.