| 초록 |
Active oxygen species (AOS) generated under atmosphere can be applied for a variously industrial process owing to extremely strong oxidative abilities. It is well known that excited singlet oxygen atom [O(1D)], ozone (O3) and hydroxyl radicals (OH*), are of interest and value in surface modification. The AOS generated under ultraviolet (UV) lamps, whose wavelength are 185 and 254 nm was used in this experiment. It is well known that methylene blue dye is easily decomposed by the ozone (O3). It is one of convenient indicators that can detect the AOS as its colour turns to be transparent after the exposure of the AOS due to degradation of the dye. In this case, the O3 is a low oxidation ability of active oxygen. To detect a higher oxidative active oxygen, it was mixed with high organic polymer, Sodium alginate, which has high affinity to methylene blue, and form the methylene blue composite film. Humidity condition affects generation species of the active oxygen. In the low humidity condition, O(1D) and O3 are generated. In the high humidity condition, the most oxidative OH* is generated. By utilizing this property, decolourization mechanism of the composite film was investigated. As a result, decolourization of this composite thin film could be observed at only in a high humidity condition, which suggests that the decolorization in high humidity was caused by the OH*. However, this specific decolourization mechanism is unknown, and we elucidate the decolourization mechanism of methylene blue dye employed sodium alginate film due to the OH*. |
