Search

Experiments have assessed various polymer composites for radiation shielding in diverse applications. These composites are lighter and non-toxic when compared to lead (Pb), making them particularly effective in diagnostic imaging for shielding against low-energy photons. This study demonstrates the fabrication of four composites by combining a base material, specifically a high-density polyethylene (HDPE) polymer, with 10% and 20% silicon (Si) and silicon carbide (SiC), respectively. Additionally, 5% molybdenum (Mo) was incorporated into the composites as a heavy metal element. The composites obtained were fabricated into 20 disks with a uniform thickness of 2 mm each. Discs were exposed to radiation from a low-energy X-ray source (32.5–64.5 keV). The chemical and physical properties of composites were assessed. The shielding ability of samples was evaluated by determining the linear and mass attenuation coefficients (μ and μm), radiation protection efficiency (RPE), half-value layer (HVL), and mean free path (MFP). According to our findings, supplementing HDPE with additives improved the attenuation of beams. The μm values showed that composite X-ray shielding characteristics were enhanced with filler concentration for both Si and SiC. Polymer composites with micro-molecule fillers shelter X-rays better than polymers, especially at low energy. The HVL and MFB values of the filler are lower than those of the pure HDPE sample, indicating that less thickness is needed to shield at the appropriate energy. HC-20 blocked 92% of the incident beam at 32.5 keV. This study found that increasing the composite sample thickness or polymer filler percentage could shield against low-energy radiation. [ABSTRACT FROM AUTHOR]

The usage of radiation is mandatory for modern life; in the same manner, controlling the outflow of harmful radiation is vital and could be achieved via employing a shielding material to eliminate any potential nuclear and radiation accidents and incidents. Considering this point, this study aims to manufacture composite samples based on waste marble as novel radiation shields. The physical and radiation shielding ability of the prepared shields were determined and analyzed. For this purpose, a high-purity germanium (HPGe) detector was used to detect the incoming photons emitted from three point sources (Am-241, Cs-137, and Co-60). The radiation attenuation factors for the new marble-based composites were measured for some energies, ranging from 0.06 to 1.333 MeV. We examined the effect of increasing the PbCO3 and CdO contents on the physical properties and radiation attenuation factors of the newly developed radiation shielding absorber. We found that the density of the samples increases from 1.784 to 1.796 g/cm3 when the CdO changes from 0 to 12.5 wt%. The linear attenuation coefficient (LAC) for all marble compositions has the maximum value at 0.06 MeV, while the LAC decreases with increasing energy. The highest LAC was found for Marb-3, with a composition of waste marble (50 wt%), polyester (25 wt%), PbCO3 (17.5 wt%), and CdO (7.5 wt%). We studied the impact of the addition of CdO on the expense of PbCO3 and we found that the half value layer (HVL) decreases with increasing the CdO content. Hence, when there is no space problem, the newly developed radiation shielding absorber can be used to maintain the cost effectiveness and environmentally friendliness of products. [ABSTRACT FROM AUTHOR]

We have attempted to develop the gamma radiation shielding abilities of newly prepared epoxy composites by introducing ZrO2. The radiation shielding parameters are experimentally reported below. The experimental setup included an HPGe detector and different radioactive point sources which emitted photons with energies of 0.06, 0.662, 1.173, and 1.333 MeV. The gamma radiation shielding abilities of the epoxy composites were examined in the context of the linear attenuation coefficient (LAC), half-value layer (HVL), radiation absorption ratio, and other factors. The experimental and Phy-X results for the LAC were compared, and acceptable consistency was reported. The lowest LAC values were reported for EBZr-0 (free of ZrO2), and we found that the photon attenuation competence of the present epoxy improved as a result of increasing the ZrO2 content. We compared the LAC values for the present epoxy composites with other samples, and we found that the prepared composites with 20% to 40% ZrO2 had higher LAC values than epoxy with 30% Yahyali Stone. The HVL lengths of the epoxy composites reduced with the addition of ZrO2 for the four selected energies, which confirmed that introducing ZrO2 improves the radiation absorption abilities of epoxy composites. At 0.06 MeV, the HVL for the ZrO2-free epoxy was 2.60 cm, which fell to 0.23 cm after adding 40% ZrO2. The mean free path (MFP) for the prepared composites was less than 1 cm at 0.06 MeV (standard for EBZr-0), while it was 1.32 cm for EBZr-10. For the other energies, it was higher than 6 cm, and became higher than 10 cm at 1.333 MeV for all composites. The obtained results suggest that non-toxic, natural, and cheap epoxy composites with high ZrO2 content have the potential to improve the gamma ray shielding competence of epoxy composites for low energy radiation applications. [ABSTRACT FROM AUTHOR]

This work aims to experimentally report the radiation attenuation factors for four different clays (red, ball, kaolin and bentonite clays) at four selected energies (emitted from Am-241, Cs-137, and Co-60). The highest relative difference in the mass attenuation coefficient (MAC) is equal to −3.02%, but most of the other results are much smaller than this value, proving that the experimental and theoretical data greatly agree with each other. From the MAC results, the shielding abilities of the clay samples at 0.060 MeV follow the order of: bentonite > red > ball > kaolin. Thus, at low energies, the bentonite clay sample provides the most effective attenuation capability out of the tested clays. The half value layer (HVL) increases as energy increases, which suggests that, only a thin clay sample is needed to sufficiently absorb the radiation at low energies, while at higher energies a thicker sample is needed to shield the same amount of high energy radiated. Furthermore, bentonite clay has the lowest HVL, while the kaolin clay has the greatest HVL at all energies. The radiation protection efficiency (RPE) values at 0.060 MeV are equal to 97.982%, 97.137%, 94.242%, and 93.583% for bentonite clay, red clay, ball clay, and kaolin clay, respectively. This reveals that at this energy, the four clay samples can absorb almost all of the incoming photons, but the bentonite clay has the greatest attenuation capability at this energy, while kaolin clay has the lowest. [ABSTRACT FROM AUTHOR]

Recently developed polymer-based composites could prove useful in many applications such as in radiation shielding. In this work, the potential of a bismuth oxide (Bi2O3) nanofiller based on an LDPE polymer was developed as lead-free X-ray radiation shielding offering the benefits of lightness, low-cost and non-toxic compared to pure lead. Three different LDPE-based composites were prepared with varying weight percentages of Bi2O3: 5%, 10% and 15%. The characterizations were extended to include structural properties, physical features, mechanical and thermal properties, and radiation shielding efficiency for the prepared nanocomposites. The results revealed that the incorporation of the Bi2O3 nanofiller into an LDPE improved the density of the composites. There was also a slight increase in the tensile strength and tensile modulus. In addition, there was a clear improvement in the efficiency of the shield when fillers were added to the LDPE polymer. The LDPE + Bi2O3 (15%) composite needed the lowest thickness to attenuate 50% of the incident X-rays. The LDPE + Bi2O3 (15%) polymer can also block around 80% of X-rays at 47.9 keV. In real practice, a thicker shield of the proposed composite materials, or a higher percentage of the filler could be employed to safely ensure the radiation is blocked. [ABSTRACT FROM AUTHOR]

Utilizing a polymer-based radiation shield offers lightweight, low cost, non-toxic compared to lead and solution for eliminating generated secondary neutrons. Incorporating silicon (i.e., one of the most abundant elements) in new applications, such as shielding, would have an impact on the economy and industry. In this study, seven potential shielding materials, composed of silicon, silicon carbide, and boron carbide embedded ethylene vinyl acetate (EVA) copolymers, are proposed. The shielding performance of these composite materials, including the attenuation coefficients (µ), the mass attenuation coefficients (µm), the half value layer (HVL), the mean free path (MFP), and the radiation protection efficiency (RPE) were examined using photon beams. Measured µm were verified against the calculated values. The averaged agreement was within ±7.4% between the experimental measurements and the theoretical calculation results. The HVL and MFP measured values for the polymer composites were lower than that for the pure EVA polymer, indicating the fillers in the polymers enhanced the shielding performance. The EVA + SiC (30%) and EVA + Si (15%) + B4C (15%) composites required the lowest thickness to stop 50% of the incident photons. The evaluation of experimental results of the RPE revealed that the polymer composites containing SiC (30%), Si (15%) + B4C (15%), or SiC (15%) + B4C (15%) succeeded in blocking 90–91% of X-rays at nearly 80 keV. However, a thicker shield of the proposed composite materials or combined layers with other high-Z materials could be used for higher energies. [ABSTRACT FROM AUTHOR]