Layer-by-layer electrostatic self-assembly deposition of lysozyme and poly(sodium 4-styrene- sulfonate) (PSS) on wool fibers which endowed them with antibacterial properties were studied. Scanning electron microscopy (SEM) presented the surface morphologies of assembled wool. Zeta potentials, dyeing, activity of lysozymes revealed the mechanism of layer-by-layer electrostatic self-assembly process on fibers and the antibacterial effects were determined. SEM showed rougher surfaces of modified wool fibers with partially-filled grooves, indicating that lysozyme and PSS were assembled on the surfaces of wool fibers. The electrical potential, dye uptake, activity of lysozyme all showed obvious “layer-by-layer alternative oscillation”, which demonstrated the changes of electrical charges on the surfaces of assembled fibers|an approximately linear decrease in UV transmissivity with the increasing assembled layers indicated that lysozymes were multilayeredly assembled on the surface of wool, these revealed the fabrication mechanism of layer-by-layer electrostatic self-assembly antibacterial coatings on fibers surfaces. Meanwhile, the activity of lysozyme was gradually increasing with the increase in the layer numbers of assembled enzyme. The antimicrobial ratio of assembled wool could reach 91.7%, indicating a good antimicrobial property.

Key words: lysozyme, immobilization, electrostatic self-assembly, antibacterial, wool