Morphology on the surface of wool fibers treated with glow discharge under atmospheric pressure

The surface structures of wool fibers treated with the glow discharge under atmospheric pressure and the low-temperature plasma were mainly examined by SEM. The ruggedness morphologies, which were caused by the oxidation-etching effects, were observed on the surface of specimens treated with oxygen low-temperature plasma. The morphology of the specimens treated with low-temperature plasma of helium gas flow was little changed compared with original one. In the case of glow discharge under atmospheric pressure, numerous granules with a diameter of ca. 0.15 mu m appeared on the cuticle layer. These granules were completely soluble in methanol. According to the XPS spectra, such granular materials consist of substances containing large amount of carboxyl group. It was suggested that such granules were composed of polar compounds with lower-molecular weight which were different from the original substance of wool fiber. It is likely that the granular materials are degraded products of the proteins in surface layer generated partly by the glow-discharge energy and remained on the surface of wool fibers due to the atmospheric pressure.