Scanning electron microscopy (SEM)

X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy in attenuated total internal reflectance mode (FTIR-ATR) were employed to probe the surface chemical and physical structure natures of the surface modified wool.The SEM analysis shows the nano-size roughness on the plasma treated or chemical surface modified wool scales.Wenzel equation and Cassie and Baxter equation are used to illustrate the relationship between surface roughness and contact angle

then to reveal the reasons why surface modifications are able to impart an improved water repellence and oil repellence and stain resistance to wool.The XPS and FTIR-ATR analyses indicate the surface disulfide bonds scission and surface lipid modification/removal on the surface modified wool.The wool surface chemical changes are beneficial for water/oil repellent agent to absorb and fix on wool fibers.The synergistic effect between surface modification and water/oil repellent finishing imparts a lotus-like effect to wool

resulting in super water repellence and oil repellence functions of wool.