Study On X-ray Shielding Composites Based On Bismuth And Europium

With the widespread use of radioactive rays,which brings social progress and also leads to a series of hazards,prolonged radiation exposure can cause irreversible damage to living organisms.Products containing lead are the most traditional X-ray shielding materials,but lead has the disadvantages of toxicity,environmental damage and weak absorption area for X-rays.How to prepare a non-toxic and environmentally friendly X-ray shielding material has become one of the key points for researchers to consider.In this study,a new X-ray shielding material preparation method is proposed to meet the current growing demand of X-ray shielding.Translated with In the study,the preparation process and the best process conditions of X-ray shielding materials are determined,and bismuth oxide nanoparticles（Bi₂O₃）and europium oxide nanoparticles（Eu₂O₃）are used for the study.The role of bismuth is a good replacement element for lead,and the rare earth element europium can compensate for the"weak absorption region"of lead.The nanoparticles of Bi₂O₃ and Eu₂O₃ before and after modification were characterized and tested by X-ray diffraction（XRD）,Fourier infrared spectroscopy（FT-IR）,transmission electron microscopy（TEM）,sedimentation volume measurement,contact angle test,etc.The results showed that the modified nanoparticles were successfully wrapped with coupling agent on the surface,and the dispersion of the modified nanoparticles in the matrix increased and the interfacial bonding between the nanoparticles and the matrix was enhanced.In this study,a combination of simulation calculations and experiments was used with Win XCOM simulation software,which can simulate the mass attenuation coefficients and reaction cross sections of elements with atomic numbers in the range of 1 to 100,as well as compounds or mixtures of these elements,in the range of incident energies from 10^-3 to 10³Me V.In this study,the shielding ability of Bi₂O₃ and Eu₂O₃ against X-rays was simulated by Win XCOM,and the mass ratio of Bi₂O₃ and Eu₂O₃ to achieve the best shielding performance was calculated.The results show that the modified Bi₂O₃ and Eu₂O₃nanoparticles with a mass ratio of 1:1 have both medium and low energy shielding performance against X-rays.Bi₂O₃/Eu₂O₃/EPVC composites were prepared by the composite of the modified nanoparticles with PVC paste resin at the mass ratio of 1:1.The effects of the content of the modified nano-filler on the properties were studied by thermogravimetric analysis,mechanical properties testing,cross section scanning and X-ray shielding performance testing.The results show that the higher the filler content is,the better the X-ray shielding performance is.When the mass ratio of EPVC matrix to the modified nano-filler is 5:2 and the thickness of the composite material is 4 mm,it can provide the best shielding effect for X rays.The mass attenuation coefficient of EPVC matrix for 60 ke V ray energy can reach1.43 cm²·g^-1,and the lead equivalent is 0.16 mm Pb.The mass attenuation coefficient of 109ke V ray energy is 0.77 cm²·g^-1,and the lead equivalent is 0.09 mm Pb.In the mechanical properties test,the best tensile properties were obtained with a matrix-to-filler mass ratio of5:1,with an elongation at break of 313%and a tensile strength of 5.04 MPa.The modified nano Bi₂O₃/Eu₂O₃/EPVC composites have good performance,and can be used to replace some functions of lead-containing materials in X-ray shielding.