Effect of modified graphene nanosheets on the properties of ²²²Rn and gamma ray multifunctional shielding polymer composite materials

Development of shielding materials for Rn-222 and gamma radiation has crucial implications for ensuring the safety of individuals. This paper reports the synthesis of modified graphene nanosheets (MGNPs) via the reaction of KH560 with graphene nanosheets (GNPs), while melt blending and hot-press molding technique were used to fabricate a multifunctional polymer composite shielding material, MGNP/WB/PMMA (polymethyl methacrylate). Successful synthesis of MGNP was confirmed by Fourier transform infrared spectroscopy, and scanning electron microscope (SEM) analysis was utilized to assess the distribution of functional fillers within the cross-section of the polymer composite. Additionally, thermogravimetric analysis (TGA) demonstrated that MGNP and WB particles enhance the thermal stability of the polymer composite materials. Compared to pure PMMA, 98.7% decrease in the radon diffusion coefficient was observed for MGNP1.5 wt%/PMMA composite material. In addition to enhance the radon-blocking characteristics of the polymer composites, inclusion of WB particles also boosts their shielding capacity against gamma radiation. The Rn-222 diffusion coefficient of MGNP1.5 wt%/WB25wt%/PMMA polymer composite material decreased by 99.6% and at energies of 60 KeV, 80 KeV, 122 KeV, 365 KeV, the mass attenuation coefficient (MAC) for the composite material increased by 0.79, 1.97, 0.57, and 0.05 cm(2)/g, respectively, compared to pure PMMA. Highlights center dot The PMMA composite materials doped with graphene nanosheets demonstrate outstanding resistance to Rn-222. center dot Graphene nanosheets modified by KH560 exhibit favorable dispersion within PMMA. center dot WB can further enhance the radon resistance of MGNP/WB/PMMA composite materials. center dot The polymer composites exhibit excellent Rn-222 and gamma ray shielding properties.