Surface modification of cellulosic fibers using dielectric-barrier discharge

The relationship between the surface chemistry of cellulosic fibers treated with an atmospheric cold plasma generated by dielectric-barrier discharge and recently discovered improvements in wet-strength and wet-stiffness was evaluated. ESCA characterization of cellulosic fibers indicates that treated fiber surfaces undergo selective oxidation, degradation, and removal of extractives and other contaminants. Fiber wettability in water increases with low dielectric-barrier discharge treatment (1.0 kW m−2 min), but diminishes with increased treatment intensity (5.0 kW m−2 min). This is related to changes in the polar and dispersive components of surface energy as determined by dynamic contact angle analysis. ESCA, combined with analysis of wettability and wet-strength properties, reveals that reductions in surface energy at increased treatment levels occur due to oxidative reactions.