Radiochromic films composed of polymer matrices and organic dyes are widely used for routine dosimetry purposes in operation of various radiation facilities—gamma and X‐ray‐irradiation, electron accelerators, and so on. However, the sensitivity of these films rapidly decreases at doses exceeding 30–50 kGy due to a saturation of their optical response, making them unsuitable for accurate dosimetry in radiation processing of polymers and composites where doses up to 200 kGy are typically employed. To overcome this limitation, the use of inorganic substances as the coloring agents of polymer‐based radiochromic films was proposed in this paper, specifically, heteropolyacidacid H3PW12O40 (tungstophosphoric acid) in the matrix of poly(vinyl alcohol) (PVA). Nanocomposite PVA/H3PW12O40 films were prepared by solution casting and their optical responses toward 60Co gamma radiation and beams of 6 MeV electrons for a dose range of 10–200 kGy were investigated. It was established that upon exposure to gamma rays and electron beams, the films turn blue and a broad absorption band at 750 nm appears in their spectra. Importantly, the radiation‐induced optical absorption increases in a linear fashion up to the dose of 150 kGy and only slightly deviates from linearity at 200 kGy. Moreover, it was found that the PVA/H3PW12O40 films have a long shelf life, are dose‐rate independent within a wide range, and color‐stable after irradiation. All these features make the nanocomposite PVA/H3PW12O40 films promising for use as routine dosimeters and dose labels in a much wider range of high doses as compared to radiochromic films based on organic dyes.

The name of the 1st author in references 1 and 3 should be O. N. Tretinnikov.

Coloration of polyvinyl alcohol–phosphotungstic acid (PVA–PTA) films by gamma radiation was studied at different concentrations of PTA. It was found that at a minimum concentration (1%), the coloration of the films occurs as a result of radiation-induced reduction of heteropolyanion by two electrons, while at high concentrations (≥20%), one-electron reduction takes place. In the intermediate range of concentrations, the fraction of PTA heteropolyanions reduced by two electrons decreases with a simultaneous increase in the fraction of one-electron reduced anions.