Development of X-ray shielding textile materials with micro and nano sized particles

Abstract

In many fields of work, including medical diagnosis and therapy, nuclear power plants and space exploration, ionizing radiation (e.g X-ray) is found. These radiation source create serious risks to human health, including mutagenic and carcinogenetic effects on bodily-organs. Therefore, it is important to limit the amount of radiation that professionals who operate in the radiation areas are exposed to. Beer-Lambert equation states that the atomic number, density and thickness of X-ray absorbing materials strongly impact X-ray attenuation performance. Lead (Pb), bismuth (Bi), tungsten (W) and barium (Ba) are common examples of the types of high- atomic number metal compounds utilized to provide efficient shielding fillers in composites with types of polymers. But lead's (Pb) toxicity and density means that it can not be used without precautions as a shielding material. High atomic number, lightweight and non-Pb radiation shielding apparel has become the focus on recent research. Accordingly, this study was conducted in order to develop lightweight, environmentally friendly, textile-based materials which has effective radiation protection using conventional textile coating technology. For this purpose, in preliminary work a coating mixture was prepared utilizing micro copper particles and water-based polymers. In addition to these, micro and nano bismuth oxide powders were employed in preparation of a coating mixture with the help of water-based polymers for this purpose. For advanced characterizing of the coated textile surfaces developed, Fourier Transform Infrared-Attenuated Total Reflectance (FTIR) and Scanning Electron Microscopy (SEM), and Energy Dispersive Spectroscopy (EDS) techniques were used. The radiation attenuation performance of the samples was, on the other hand, measured in accordance to Narrow Beam geometry described in the standard TS EN 61331-1:2014 at Nuclear Energy Research Institute, Turkish Energy, Nuclear and Mineral Research Agency (TENMAK- NÜKEN). The findings of the study have shown that it is possible to produce textile based shielding materials offering lead-equivalent protection without using any lead. Furthermore, it has been shown that the samples with nano powder doping had a greater radiation attenuation rate than those with the micro powder doping, while having almost identical volumetric ratios of powder and coating thicknesses. When comparing the samples with a volumetric ratio of 60%, the 3 plied composite textile based materials containing nano bismuth oxide powder with a thickness of 0.9225 mm provide 83% attenuation at 40 kV whereas the same material present 71.3 % protection at 60 kV. When it comes to the measurement results of the micro bismuth oxide powder with the same values however show 60.2% attenuation at 60 kV. In the study, it was demonstrated that nano-sized powders had a more uniform dispersion in the materials developed than the micro-sized powder particles. The results have also suggested that the layered textile based composite material may attain a sufficient level of lead equivalent. Also, it was found that the attenuation ratio of such materials decreases as the X-ray energy increases. Moreover, by increasing the thickness of the materials the X-ray shielding levels can be increased by 95% and over. In conclusion, it has been shown that lead-free, nature-friendly textile based materials which contain nano and micro powder for use in the field of medical industry can have sufficient lead equivalent protection against X-rays by using traditional textile production methods.