Radiochromic reactions in repetitive X-ray irradiations of a novel gel complex composed of polyvinyl alcohol, iodide, and silica nanoparticles (PAISiN)

Radiochromic materials have good potentials for the prompt on-site detection of accidental high-dose exposure. One of the drawbacks of using these materials in various occasions is that they cannot generally be reused after coloration. In the present study, a recently developed radiochromic complex composed to polyvinyl alcohol, iodide, and silica nanoparticles named "PAISiN," was repeatedly annealed at 40°C for 3 hours and irradiated with X-rays (160 kV, 6.3 mA) at 8, 4 and 2 Gy(H2O) each up to a total dose of 24 Gy. RGB color images of the PAISiN samples were acquired with a flatbed scanner and analyzed using image processing software. As results, PAISiN showed reproducible responses in all fractionated dose levels. Additionally, it was confirmed that the PAISiN samples annealed after repetitive irradiation maintained a stable white color for 12 days at room temperature. From these findings, it is expected that PAISiN could be used repeatedly and effectively for personal monitoring of accidental high-dose exposure under normal indoor conditions.