Influence of embedded boron nitride nanosheets on Fe3+ diffusion in Fricke gel dosimeter and its response to γ rays.

The Fe3+ diffusion in Fricke gel dosimeter, widely used for the measurement of accurate dose distributions in radiotherapy, results in a gradual blurring of the dose pattern with time after irradiation. In order to solve this issue, we embedded Fricke gel dosimeter with boron nitride nanosheets. The results show that the nanosheets-embedded gel dosimeter exhibited lower diffusion rate of Fe3+ ions (0.23 mm2 h−1) and a good response to γ irradiation in UV absorbance spectra. The hydrogen bond barriers between nanosheets and the gels were an important mechanism for the hindrance to Fe3+ diffusion besides the physical blocking of the Fe3+ motion by boron nitride nanosheets. This work will benefit understanding the mechanism for the limit on irons' diffusion and developing three dimensional Fricke gel dosimeter for the measurement of accurate dose distributions. [ABSTRACT FROM AUTHOR]