| Abstrakt: |
Radiation shielding materials of lightweight and geometrical compatibility are highly desired in a series of important applications including nuclear energy, medical imaging, radiotherapy treatment, industrial inspection, and occupational health protection. In this regard, advanced polymer composites embedded with micro- and nanosize particles show great potential as next-generation radiation shielding materials. In this work, we report an innovative dual-polymerization methodology to enable the quick fabrication of radiation shielding materials, i.e., poly(methyl methacrylate) (PMMA) composites with 0–30 wt % Bi2O3and ZrO2fillers, which exhibit exciting shielding performance. The surface features and dispersion state of fillers into the PMMA matrix were investigated through laser confocal microscopy. The Fourier transform infrared measurements revealed the presence of functional groups from PMMA and embedded particles, while the results of Raman spectroscopy showed high-efficiency polymerization among all PMMA composites. In addition, the mass attenuation coefficients and the half-value layer of these PMMA composites were measured by using a high-purity germanium (HPGe) detector for γ-rays of Am-241 and Ba-133 radioactive sources. Our results show that the shielding capabilities of as-fabricated PMMA composites are enhanced with the increasing loading of fillers from 0 to 30 wt %. The mass attenuation coefficient was enhanced 14 times for the composite containing 30 wt % fillers at 59 keV energy, compared to the pure PMMA (0 wt %). The experimental results of γ-ray shielding measurements also agreed well with the theoretical calculation of XCOM and Phy-X. Simultaneously, SRIM calculation was performed to study the shielding performance of PMMA composites with respect to the charged particles. The projected range of pure PMMA is much higher than particle-embedded PMMA composites, indicating an efficient stopping power of Bi2O3and ZrO2particles. This work confirms the viability of employing dual polymerization for fast and high-efficiency fabrication of particle-embedded polymer composites for γ radiation shielding. PMMA composites enhanced with 30 wt % ZrO2and Bi2O3demonstrate exceptional gamma and charged particle shielding capabilities among other prepared composites. |
