HEA-PVA gel system for UVA radiation dose measurement

- A gel system based on glutaraldehyde and polyvinyl alcohol was presented.
- 2-Hydroxyethyl acrylate can be used as monomer for UV polymer dosimeter.
- We build a relationship between UV dose and the gels' optical absorbance.
- The HEA-PVA gel dosimeter has good stability、sensitivity and low diffusion.
- The UV dose measurement range was 0-560 J/cm2.

Acrylic monomer is known to be sensitive to ultraviolet radiation (UVR) through photoinitiator. Upon irradiation, the acrylic monomers formed stable polymer through free radical polymerization, hence its appearance will change from colorless and transparent to colored and non-transparent. Furthermore, the degree of changes was based on the UVR dose, and those optical changes could be detected by UV-vis spectrophotometer at the fixed wavelength of 550 nm. In this study, we used 2-hydroxyethyl acrylate (HEA) as acrylic monomer, which mixed with polyvinyl alcohol (PVA), and finally obtained a three-dimensional hydrogel material through cross-linking by glutaraldehyde (GA). After doping with photoinitiator-Bis(2,6-difluoro-3-(1-hydropyrro-1-yl)-phenyl) titanocene (784), the gel material was sensitive to UV-A radiation (400-315 nm), which forms an important part (~ 97%) of the natural solar UV radiation reaching the earth surface. The behavior of different formulations' dose response sensitivity, detector linearity, diffusion, stability after UVA radiation were investigated. The results showed that when the dosage range of UVA radiation was 0-560 J/cm2, the gel had a great sensitivity and the linearity was found to be closed to 1. After UVA radiation, the gel also had a very good optical stability. In addition to this, when irradiated with high dose UVA, the gel could maintain a low diffusion.