Reversible radiochromic plate based on polyvinyl alcohol-iodide complex containing silica nanoparticles

Thermally Controllable Decolorization of Reusable Radiochromic Complex of Polyvinyl Alcohol, Iodine and Silica Nanoparticles (PAISiN) Irradiated with γ-rays

“…The initial white color of PAISiN was changed to a red color immediately after γ-ray irradiation, as previously observed for 30 kV X-rays [17]. As examples, selected color images of PAISiN stored at room temperature (20 °C) for 0.25 h, 11.6 h and 70.6 h after irradiation are shown in Figure 2.…”

“…In reference to a preceding study [31], nanoparticles of SiO 2 (SiNP) with a diameter of 12 nm were extracted from a commercial product of SiNP-dispersed aqueous solution (LUDOX HS-40, Sigma-Aldrich Co., Ltd., St. Louis, MI, USA) by washing out repeatedly with distilled water, and then 12 mL of 20 wt% SiNP solution was made. According to the finding that the radiation sensitivity of the radiochromic reaction of PAISiN was exponentially enhanced with increasing SiNP concentration [17], 1 mL of the PVA-I solution and 2 mL of the SiNP solution were put into a transparent quartz cell with dimensions of 12.5 × 12.5 × 58.0 mm 3 coupled with a screw-type cap and mixed well by careful shaking to achieve the final composition of 0.66 mmol L −1 , 0.3 mol L −1 KI and 13 wt% SiNP, which is slightly acidic due to the contribution of the residual acetyl group of polyvinyl acetate. It is considered that PVA is absorbed onto the SiNP surface due to the hydrogen bonding between hydroxyl groups and those in PVA in this complex [32].…”

“…As a consequence, the authors focused on a complex composed of polyvinyl alcohol (PVA), iodide (I) and silica nanoparticles (SiNP), named "PAISiN" here. This complex was developed and investigated with 30 kV X-rays by Miyoshi et al [17]. They found that the addition of SiNP as a reductant worked as a radiation sensitizer for enhancing the radiochromic reaction.…”

Radiation‐sensitive nanogel‐incorporated Fricke hydrogel dosimeters with reduced diffusion rates

“…The influence of CHPA concentration on the stability of nanogel‐incorporated Fricke hydrogels was investigated, which is important for practical applications, as shown in Figure 4A. ImageJ software was used to quantify the intensity of the optical photograph in the inset, and five areas in each group were randomly selected for analysis 39 . Compared with the control group, the optical intensity (expressed as gray level) of experimental samples decreases gradually with the increased CHPA concentration.…”

“…and five areas in each group were randomly selected for analysis. 39 Compared with the control group, the optical intensity (expressed as gray level) of experimental samples decreases gradually with the increased CHPA concentration. It indicates that excessive CHPA significantly increases the background absorbances of dosimeters, which is unbeneficial for their stability and dose response.…”