A colorimetric indicator for detection of hydroxyl radicals in atmosphere using a methylene blue dye based on nafion film

Methylene blue based on the nafion film was prepared and chemical reactions in contact with active oxygen species were estimated. In addition, decolorization mechanism of the film due to exposure of the active oxygen species is discussed. The active oxygen species was exposed to the methylene blue based on the nafion film in low and high humidity conditions. Although decolorization of the film was hardly observed when it was exposed in the ozone and the active oxygen species in low humidity condition, the decolorization was observed when it was exposed in the high humidity condition. It is considered that the decolorization of the film due the active oxygen species exposure relates to the degradation reaction of the methylene blue molecule due to hydroxyl radicals. (C) 2015 Elsevier Ltd. All rights reserved.