Radiation induced colour changes in a spiropyran/BaFCl:Eu2+/polystyrene composite film and nonwoven fabric
A polystyrene (PS) based composite film and nonwoven fabric consisting of a photochromic spiropyran dye, 1,3,3 trimethylindolino 6' nitrobenzopyrylospiran (6 nitro BIPS) and a photostimulable phosphor, europium doped barium fluorochloride (BaFCl:Eu2+ were developed for the detection of X ray exposure doses on the order of a milligray (mGy) The PS based composite film and the nonwoven fabric were successfully prepared according to a cast method and a forcespinning method. The colours of the composite film and the nonwoven fabric were changed from white to deep blue, and a broad absorption band appeared, with a maximum at 604 nm, with X ray exposures of 0.1 Gy and 5.6 Gy, respectively. The maximum sensitivity of 0.1 Gy of the composite film is equivalent to the radiation dose limit for workers who conduct emergency work.