Three kinds of fabrics-cotton, silk and nylon-were exposed to artificially-produced nitrogen dioxide and ozone gases in a glass chamber in a laboratory. The gases were supplied at constant concentrations of 290 and 0.5 ppm for 96 h, respectively. The fabric surfaces after exposure were examined with scanning electron microscopy.
As for the exposure to nitrogen dioxide and ozone gases, the following result was observed : Small cracks and splits appeared on the surface of cotton fiber after 48 h of exposure to 290 ppm of nitrogen dioxide. On the silk fiber, the number of fibrils was observed to be seriously affected by the exposure time. On the nylon fiber after 48 h of exposure, a swelling condition was observed on the surface. It is considered that nitrogen dioxide may cause serious damage, due to its acidity and oxidation performance. On the other hand, the depth of wrinkles of cotton fiber seemed to become more significant according to the exposure duration after 96 h of exposure to 0.5 ppm of ozone. Fine fibrils appeared on the surface of silk fiber. Detachment of fibrils along the axis was found on the surface condition of the nylon fiber. Ozone is also considered one of the damage factors in the environment due to its strong oxidation performance.