ILJA SHENDEROVICH and HANS-HEINRICH LIMBACH

The surface characteristics of several natural fibers—flax, hemp and cellulose— were investigated using scanning electron microscopy, BET-surface area and zeta (-) potential measurements. -Potential measurements using the streaming poten-tial method were performed in order to study the water uptake behavior as well as the surface properties of several natural fibers. The influence of different flax-fiber separation methods and several modifications, like industrial purification, and such a treatment followed by alkaline purification as well as polypropylene grafting on the fiber surface morphology, surface area and time- and pH-depending -poten-tials were studied. The time-dependence of the -potential, measured in 1 mM KCl solution, offers an alternative possibility to estimate the water uptake behavior for nearly all investigated natural fibers. The water uptake data derived from the -po-tential measurements ( f (t)) were compared with data from conventional water adsorption studies for some chosen examples