Polymeric composite materials for radiation shielding: a review

Microstructure and radiation shielding capabilities of Al-Cu and Al-Mn alloys

In this study, the microstructure and elemental analysis of aluminum-copper alloy type-2024, Al-2024, and aluminum-manganese alloy type-3003, Al-3003, have been investigated by using a scanning electron microscope (SEM) equipped with Energy dispersive spectroscopy (EDS) detector. Experimental and theoretical radiation shielding studies were performed to assess the radiation shielding capabilities of the studied alloys. Considering the radiation shielding theoretical assessment, some reliable software tools were used, such as Phy-X/PSD, MCNP5, NXCom, and MRCsC. The microstructural observations and results have shown the presence of second phases rich with the main alloying elements in both alloys. Considering Al-2024 alloy, coarse second-phase particles, having a size range of 8-15 μm, were found aligning in lines parallel to the rolling direction, whereas smaller ones, having a size range of 2-8 μm, were found decorated the grain boundaries. Also, dark holes represent the pull-out large particles separated during preparation indicated poor adhesion with the main matrix that could be a result of losing particle coherency with the matrix where the misorientation in-between the atomic planes increase. However, better adhesion of the second-phase particles with the matrix, which were found possessing smaller particle size, have been observed in the Al-3003 alloy indicating good coherency and better manufacturing process for the non-heat-treatable alloy. The second-phase particles in case of Al-2024 alloy were found containing significant content of high-Z elements like Cu with greater volume fraction equals 7.5%. On the other side, Al-3003 alloy has possessed second-phase particles which lack of high-Z elements with only volume fraction equals 3.5%. All the former besides the higher density and content of high-Z elements like copper in Al-2024 alloy in compare to Al-3003 alloy and pure aluminum, led to relatively better radiation shielding capabilities against energetic photons, the highest in the low energy band and decreases with the increase of the photon energy, and slight superiority in the case of fast neutrons with only 3%inc. over pure aluminum. For instance, the radiation protection efficiency (RPE) values dropped from about; 23.2, 21.6, and 20.8% at 0.100 MeV to only 5.7, 5.9, and 5.6% at Eγ = 2 MeV, for; Al-2024, Al-3003, and Al-Pure, respectively."Please check and confirm that the authors and their respective affiliations have been correctly identified and amend if necessary.""confirmed".

Preparation, physical, optical, ESR and γ-ray attenuation efficacy investigation of copper oxide/silver borosilicate glass

The sonication method was used to prepare a new set of CuO and CuO/Ag nanocomposites. The particle size was estimated using XRD and HR-TEM while the morphology of the nanoparticles was investigated with SEM. The average particle sizes of CuO and Ag falls in the 29.32-35.80 nm and 35.13-45.95 nm ranges, respectively. XRD declared that CuO has the space groups C 1 c 1 (9) and C 1 2/c 1 (15), while silver has space group F m -3 m (225). XPS analysis indicated the presence of Ag as Ag0 and Cu as Cu2+. Nano-oxide and nanocomposites were used to synthesis CuO and CuO/Ag doped lithium-zinc borosilicate glass. Physical parameters of the glass samples were calculated including density, V m , V o , V m B , OPD, d B - B , n b , and N, R p , and R i depending on Ag and CuO mole fractions. The physical properties of glass indicated an increase in density and an initial expansion in glass structural network with the addition of silver metal due to its larger size followed by a compression as its molar ratio increase due to its higher C no . XRD measurements were reported for the glass samples doped with nanoparticles, proving the amorphous phase. ESR measurements were determined for all glass samples to detect the nature of the doped nanoparticles when incorporated inside a glassy matrix where CuO was found as tetragonal in octahedral sites and silver can be transformed after melting inside the glass matrix into Ag+ to form more stable Ag y x + clusters.The fabricated sample of CuAgB-4 with significant nano silver doping (7.32% mol) has the maximum LAc and effective atomic number. Nano silver content increases the γ -RdSg in the lithium-zinc borosilicate glasses.

Damage Mechanisms in Polyalkenes Irradiated with Ultrashort XUV/X-Ray Laser Pulses

Although polymers are widely used in laser-irradiation research, their microscopic response to high-intensity ultrafast XUV and X-ray irradiation is still largely unknown. Here, we comparatively study a homologous series of alkenes. The XTANT-3 hybrid simulation toolkit is used to determine their damage kinetics and irradiation threshold doses. The code simultaneously models the nonequilibrium electron kinetics, the energy transfer between electrons and atoms via nonadiabatic electron-ion (electron-phonon) coupling, nonthermal modification of the interatomic potential due to electronic excitation, and the ensuing atomic response and damage formation. It is shown that the lowest damage threshold is associated with local defect creation, such as dehydrogenation, various group detachments from the backbone, or polymer strand cross-linking. At higher doses, the disintegration of the molecules leads to a transient metallic liquid state: a nonequilibrium superionic state outside of the material phase diagram. We identify nonthermal effects as the leading mechanism of damage, whereas the thermal (nonadiabatic electron-ion coupling) channel influences the kinetics only slightly in the case of femtosecond-pulse irradiation. Despite the notably different properties of the studied alkene polymers, the ultrafast-X-ray damage threshold doses are found to be very close to ∼0.05 eV/atom in all three materials: polyethylene, polypropylene, and polybutylene.

Advanced polymeric matrix utilizing nanostructured bismuth and tungsten oxides for gamma rays shielding

In this study, the shielding properties of novel polymer composites, developed by integrating glycidyl methacrylate with nanoparticles of bismuth oxide (Bi2O3) and tungsten oxide (WO3), were explored. The ability of the composites to attenuate gamma radiation was evaluated by measuring the emissions from Ba-133, Co-60, Cs-137, and Na-22. X-ray diffraction (XRD) spectra were obtained for both the pure polymer glycidyl methacrylate and the samples containing nanostructures of Bi2O3, Bi2O3/WO3, and WO3, and scanning electron microscopy (SEM) was used to analyze the samples. The incorporation of Bi2O3 and WO3 nanoparticles into the polymer glycidyl methacrylate matrix significantly enhanced the composites' ability to attenuate gamma radiation, as demonstrated by the increased linear and mass attenuation coefficients. The results showed good agreement between the experiment and the XCOM database. The composites exhibited significant efficiency in attenuating lower-energy gamma rays, which is particularly advantageous in the medical and nuclear industries.

Advanced Electrospun Composites Based on Polycaprolactone Fibers Loaded with Micronized Tungsten Powders for Radiation Shielding

Exposure to high levels of radiation can cause acute, long-term health effects, such as acute radiation syndrome, cancer, and cardiovascular disease. This is an important occupational hazard in different fields, such as the aerospace and healthcare industry, as well as a crucial burden to overcome to boost space applications and exploration. Protective bulky equipment made of heavy metals is not suitable for many advanced purporses, such as mobile devices, wearable shields, and manned spacecrafts. In the latter case, the in-space manufacturing of protective shields is highly desirable and remains an unmet need. Composites made of polymers and high atomic number fillers are potential means for radiation protection due to their low weight, good flexibility, and good processability. In the present work, we developed electrospun composites based on polycaprolactone (polymer matrix) and tungsten powder for application as shielding materials. Electrospinning is a versatile technology that is easily scalable at an industrial level and allows obtaining very lightweight, flexible sheet materials for wearables. By controlling tungsten powder size, we engineered homogeneous, stable and processable suspensions to fabricate radiation composite shielding sheets. The shielding capability was assessed by an in vivo model on prototype composite sheets containing 80 w% of W filler in a polycaprolactone (PCL) fibrous matrix by means of irradiation tests (X-rays) on mice. The obtained results are promising; as expected, the shielding effectivity of the developed composite material increases with the thickness/number of stacked layers. It is worth noting that a thin barrier consisting of 24 layers of the innovative shielding material reduces the extent of apoptosis by 1.5 times compared to the non-shielded mice.

Enhanced radiation shielding efficiency of polystyrene nanocomposites with tailored lead oxide nanoparticles

In this study, we investigated a novel polymer nano-composite, PS-PbO, containing two distinct nano-sizes of lead oxide nanoparticles (PbO-A and PbO-B), in addition to the bulk size (PbO-K). These nanoparticles were embedded separately in a polystyrene (PS) matrix at different weight percentages (10%, 15%, 25%, and 35%) using roll mill mixing and compressing molding. Our evaluation focused on the radiation attenuation ability of PS-PbO and the effect of particle size, considering gamma-ray energies ranging from 0.06 to 1.3 MeV (from sources like 241Am, 133Ba, 137Cs, and 60Co). The linear attenuation coefficient (LAC) was determined by analyzing samples of the synthesized composite with different thicknesses. Then, various shielding parameters were calculated, including total molecular, atomic, and electronic cross-sections (σmol, σatm, σel), as well as the effective atomic number and the electron density (Zeff and Neff). Surprisingly, modifying PbO particle sizes had a significant impact on shielding efficiency. For instance, the composite with 25 wt% of the smallest PbO-B particles showed a 26.7% increase in LAC at 0.059 keV compared to the composite with 25 wt% of PbO-K (larger particles). Notably, the LAC peaked at low energy (0.059 keV), close to the K-edge of Pb, where interaction is directly proportional to Z4. With increasing PbO concentrations, the LAC of PS-PbO composites increased steadily. Additionally, as PbO concentration increased, the composite's effective atomic number Zeff and the electron density Neff increased, leading to a greater total Gamma-ray interaction cross-section. Furthermore, when comparing the Half-Value Layers of the novel nanocomposite to traditional lead shielding, a 70% reduction in mass was observed. Notably, the composite containing the smallest nano-size of PbO exhibited the highest radiation-shielding efficiency among all combinations and could therefore be used to create inexpensive and lightweight shields.

Thermal Weathering of 3D-Printed Lunar Regolith Simulant Composites

The production of lunar regolith composites is a promising venture, especially when enabled by extrusion-based additive manufacturing techniques such as direct ink write. However, both three-dimensional (3D) printing production and usage of polymer composites containing regolish on the lunar surface are challenges due to harsh environmental conditions such as severe thermal cycling. While thermal degradation in polymer composites under thermal cycling has been studied, there is limited understanding of how polymer properties impact the mechanical performance of lunar regolith composites when both printing and usage are carried out under extreme thermal conditions. Here, we aim to bridge that gap through the creation of composites containing a lunar Highlands regolith simulant suspended in an ultraviolet (UV) curable binder, which were printed at -30 °C and thermally cycled between weekly lunar day (127 °C) and weekly night (-190 °C) temperatures. We validate that thermal stresses cause both physical and chemical degradation since the regolith simulant composites become stiffer, more porous, and show yellowing after exposure to thermal cycling. Moreover, we indicate that chemical degradation mechanisms seem to compete with residual polymerization in certain formulations. We attribute this phenomenon to partial crystallization of monomer species during printing at -30 °C, resulting in low vinyl bond conversion during initial curing. The results presented here shed light on the intricate interplay between thermal stresses, uncured polymer properties, and degradation mechanisms, which can help guide future use cases of regolith composites for lunar infrastructure needs.

Graphene-based nanocomposites as gamma- and X-ray radiation shield

Commonly used materials for protection against ionizing radiation (gamma and X-ray energy range) primarily rely on high-density materials, like lead, steel, or tungsten. However, these materials are heavy and often impractical for various applications, especially where weight is a key parameter, like in avionics or space technology. Here, we study the shielding properties of an alternative light material-a graphene-based composite with a relatively low density ~ 1 g/cm3. We demonstrate that the linear attenuation coefficient is energy of radiation dependent, and it is validated by the XCOM model, showing relatively good agreement. We also show that the mass attenuation coefficient for selected radiation energies is at least comparable with other known materials, exceeding the value of 0.2 cm2/g for higher energies. This study proves the usefulness of a commonly used model for predicting the attenuation of gamma and X-ray radiation for new materials. It shows a new potential candidate for shielding application.

3D Printing of Composite Radiation Shielding for Broad Spectrum Protection of Electronic Systems

The miniaturization of satellite systems has compounded the need to protect microelectronic components from damaging radiation. Current approaches to mitigate this damage, such as indiscriminate mass shielding, built-in redundancies, and radiation-hardened electronics, introduce high size, weight, power, and cost penalties that impact the overall performance of the satellite or launch opportunities. Additive manufacturing provides an appealing strategy to deposit radiation shielding only on susceptible components within an electronic assembly. Here, a versatile material platform and process to conformally print customized composite inks at room temperature directly and selectively onto commercial-off-the-shelf electronics is described. The suite of inks uses a flexible styrene-isoprene-styrene block copolymer binder that can be filled with particles of different atomic densities for diverging radiation shielding capabilities. Additionally, the system enables the combination of multiple distinct particle species within the same printed structure. The method can produce graded shielding that offers improved radiation attenuation by tailoring both shield geometry and composition to provide comprehensive protection from a broad range of radiation species. The authors anticipate this alternative to traditional shielding methods will enable the rapid proliferation of the next generation of compact satellite designs.

Study on polymer composites with glass for gamma ray shielding

The shielding of gamma radiation is of the utmost importance in industries, such as nuclear power plants, medical imaging, and space exploration. For the purpose of shielding objects in such an environment, it is essential to design materials with flexibility as well as high shielding capability. In order to enhance the radiation attenuation effectiveness of polymers, such as polyvinyl alcohol (PVA), glass has been blended with varying percentages. The fabricated composite has been subjected to gamma-ray interaction studies. The radiation shielding parameter, such as mass attenuation coefficient (μ/ρ), has been determined for various energies, such as 137Cs (661.6 keV) and 60Co (1173 and 1332 keV). It is observed that the PVA composite with glass exhibits improved gamma radiation shielding properties compared to PVA. Therefore, the present work paves the way for the utility of PVA polymer with glass, offering a cost-effective and sustainable approach to gamma radiation shielding in radiation environments.

Investigating polyurethane foam loaded with high-z nanoparticles for gamma radiation shielding compared to Monte Carlo simulations

Since the beginning of research into radiation and protection against it, the importance of searching for proper materials against radiation hazards has been recognized. Gamma radiation protection materials usually deal with heavy elements with high prices, which are hard to maintain. Polyurethane-based (PU) materials are popular in sound and thermal insulation due to, their low-weight properties and, most importantly, fast and convenient construction ingredients. PU foams (PUF) can be used as radiation shield and noise and heat resistance due to their approachability, light-weight, high resistance, and comfortable construction. This study involved simulation and an experiment to construct and investigate the properties of Polyurethane material doped with lead oxide as a gamma shield. The shield was considered in several weight fractions of lead, yielding several samples. The MCNPX 2.6 Monte Carlo code has been utilized for simulation procedure, and 137Cs was employed as the gamma source in both simulation and experiment. The results offer a promising response against the gamma radiation and are suitable for attenuating gamma rays.

Production of Composite Zinc Oxide-Polylactic Acid Radiopaque Filaments for Fused Deposition Modeling: First Stage of a Feasibility Study

Three-dimensional printing technologies are becoming increasingly attractive for their versatility; the geometrical customizability and manageability of the final product properties are the key points. This work aims to assess the feasibility of producing radiopaque filaments for fused deposition modeling (FDM), a 3D printing technology, starting with zinc oxide (ZnO) and polylactic acid (PLA) as the raw materials. Indeed, ZnO and PLA are promising materials due to their non-toxic and biocompatible nature. Pellets of PLA and ZnO in the form of nanoparticles were mixed together using ethanol; this homogenous mixture was processed by a commercial extruder, optimizing the process parameters for obtaining mechanically stable samples. Scanning electron microscopy analyses were used to assess, in the extruded samples, the homogenous distribution of the ZnO in the PLA matrix. Moreover, X-ray microtomography revealed a certain homogenous radiopacity; this imaging technique also confirmed the correct distribution of the ZnO in the PLA matrix. Thus, our tests showed that mechanically stable radiopaque filaments, ready for FDM systems, were obtained by homogenously loading the PLA with a maximum ZnO content of 6.5% wt. (nominal). This study produced multiple outcomes. We demonstrated the feasibility of producing radiopaque filaments for additive manufacturing using safe materials. Moreover, each phase of the process is cost-effective and green-oriented; in fact, the homogenous mixture of PLA and ZnO requires only a small amount of ethanol, which evaporates in minutes without any temperature adjustment. Finally, both the extruding and the FDM technologies are the most accessible systems for the additive manufacturing commercial apparatuses.

Development of Lead-Free Materials for Radiation Shielding in Medical Settings: A Review

Radiation protection is an essential issue in diagnostic radiology to ensure the safety of patients, healthcare professionals, and the general public. Lead has traditionally been used as a shielding material due to its high atomic number, high density, and effectiveness in attenuating radiation. However, some concerns related to the long-term health effects of toxicity, environmental disease as well as heavy weight of lead have led to the search for alternative lead-free shielding materials. Leadfree multilayered polymer composites and non-lead nano-composite shields have been suggested as effective shielding materials to replace conventional lead-based and single metal shields. Using several elements with high density and atomic number, such as bismuth, barium, gadolinium, and tungsten, offer significant enhancements in the shielding ability of composites. This review focuses on the development and use of lead-free materials for radiation shielding in medical settings. It discusses the drawbacks of traditional lead shielding, such as toxicity, weight, and recycling challenges, and highlights the benefits of lead-free alternatives.

Physical, structural and nuclear radiation shielding behavior of Ni-Cu-Zn Fe2O4 ferrite nanoparticles

In this study, Ni-Cu-Zn Fe2O4 ferrite nanoparticles have successfully been synthesized utilizing the Co-precipitation technique. The primary objectives encompassed elucidating phase purity, discerning functional groups, scrutinizing surface morphology, and conducting structural analyses. To accomplish these objectives, a battery of advanced characterization techniques was employed, including power X-ray diffraction, Transmission infrared spectroscopy, UV-Visible spectrophotometer, and Scanning electron microscopy. Furthermore, the investigation was extended to the assessment of the gamma ray shielding properties exhibited by the synthesized Ni-Cu-Zn Fe2O4 nanoparticles, spanning an energy range from 122 keV to 1330 keV. This evaluation was carried out through the utilization of a NaI(Tl) detector coupled with a PC-based multichannel analyzer. The acquired data were meticulously compared with established theoretical value. The results of this study point to a viable route for using this simple, cost-effective, and low-temperature synthesis approach to create nanomaterials suited for gamma ray shielding applications, as well as broader radiation protection. This novel technique has the potential to significantly improve radiation shielding technology. Along with this fast neutron attenuation capability of this prepared ferrite samples have been studied in terms of fast neutron removal cross section.

Attenuation properties of poly methyl methacrylate reinforced with micro/nano ZrO2 as gamma-ray shields

This research aimed to examine the radiation shielding properties of unique polymer composites for medical and non-medical applications. For this purpose, polymer composites, based on poly methyl methacrylate (PMMA) as a matrix, were prepared and reinforced with micro- and nanoparticles of ZrO2 fillers at a loading of 15%, 30%, and 45% by weight. Using the high purity germanium (HPGe) detector, the suggested polymer composites' shielding characteristics were assessed for various radioactive sources. The experimental values of the mass attenuation coefficients (MAC) of the produced composites agreed closely with those obtained theoretically from the XCOM database. Different shielding parameters were estimated at a broad range of photon energies, including the linear attenuation coefficient (μ), tenth value layer (TVL), half value layer (HVL), mean free path (MFP), effective electron density (Neff), effective atomic number (Zeff), and equivalent atomic number (Zeq), as well as exposure buildup factor (EBF) and energy absorption buildup factor (EABF) to provide more shielding information about the penetration of γ-rays into the chosen composites. The results showed that increasing the content of micro and nano ZrO2 particles in the PMMA matrix increases μ values and decreases HVL, TVL, and MFP values. P-45nZ sample with 45 wt% of ZrO2 nanoparticles had the highest μ values, which varied between 2.6546 and 0.0991 cm-1 as γ-ray photon energy increased from 0.0595 to 1.408 MeV, respectively. Furthermore, the highest relative increase rate in μ values between nano and micro composites was 17.84%, achieved for the P-45nZ sample at 59.53 keV. These findings demonstrated that ZrO2 nanoparticles shield radiation more effectively than micro ZrO2 even at the same photon energy and filler wt%. Thus, the proposed nano ZrO2/PMMA composites can be used as effective shielding materials to lessen the transmitted radiation dose in radiation facilities.

Preparation of eGaIn NDs/TPU Composites for X-ray Radiation Shielding Based on Electrostatic Spinning Technology

Thermoplastic polyurethane (TPU) composites with eutectic gallium (Ga) and indium (In) (eGaIn) fillings of 0 wt%-75 wt% were prepared using the electrostatic spinning method. Field emission scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier-transform infrared (FTIR) spectroscopy were used to characterize the eGaIn NDs/TPU composites. To evaluate their X-ray shielding properties, Phy-X/PSD and WinXCom were employed to calculate the mass attenuation coefficients, linear attenuation coefficients, half-value layers, tenth value layers, mean free paths, and adequate atomic numbers of the eGaIn NDs/TPU composites. The SEM results indicated that the eGaIn nanodroplets were evenly distributed throughout the TPU fibers, and the flowable eGaIn was well-suited for interfacial compatibility with the TPU. A comparison of the eGaIn NDs/TPU composites with different content levels showed that the composite with 75 wt% eGaIn had the highest μm at all the evaluated energies, indicating a superior ability to attenuate X-rays. This non-toxic, lightweight, and flexible composite is a potential material for shielding against medical diagnostic X-rays.

Fabrication of cadmium chloride PVA polymer composite for γ-ray shielding

Reducing the effect of exposure to radiation in places such as radiation labs, nuclear reactors, radiotherapy facilities, industries involving radiation, etc., is essential for the health of radiation workers. In such cases materials having flexibility added with high attenuation coefficient of radiation is required for manufacturing wearables. Even though materials such as lead compounds, building materials, etc., have high attenuation coefficient, they are toxic and rigid, making them unsuitable for this purpose. In this regard, blending compounds with polymers would lead to flexible materials with high shielding capability. In the present work, 25 wt% cadmium chloride in polyvinyl alcohol (PVA) polymer composite has been prepared using solution casting method. The obtained polymer composite is characterised by energy dispersive X-ray spectroscopy. The mass attenuation coefficients (μ/ρ) and half value layer (HVL) of gamma radiations were measured at various energies 511, 661, 1173 and 1332 keV using calibrated gamma ray spectrometer with NaI(Tl) detector and compared to WinXCom-calculated theoretical values. The measured μ/ρ and HVL are 0.089, 0.078, 0.064, 0.061 cm2/g and 0.685, 0.778, 0.985, 1.003 cm, respectively. It is found that the obtained experimental values are in good agreement with theoretical values within the experimental errors. Also, it is observed that the μ/ρ decreases and HVL increases with increase in energy. Even though PVA is not radiation resistant, when it is blended with 25 wt% cadmium chloride it shows good shielding property. Thus, the fabricated cadmium chloride-PVA polymer composite can be used for radiation shielding instead of toxic and expensive materials.

Medical-Radiation-Shielding Film Fabricated by Imitating the Layered Structure Pattern of Abalone Shell and Verification of Its Shielding Effect

Radiation-shielding clothing for medical workers must be light and thin, thus ensuring flexibility. However, controlling the thickness and weight is limited by shielding performance requirements. This study aims to improve shielding performance by considering a shielding structure that mimics the internal structure of an abalone shell. Two shields were produced: a sheet made with a carrier process using a liquid polymer and tungsten mixture, and a fillet made by compounding the same material and laminated using a heat-treatment press after the injection process. The tungsten content and thickness were the same at 85 wt% and 0.3 mm, respectively. In the high-energy region, the shielding film based on the laminated structure of abalone shells showed a shielding rate that was higher by more than 7%. Compared to that of a 0.3 mm lead plate, the shielding ratio of the shielding film was approximately 16% lower at 120 kVp, thereby confirming the radiation-shielding effect of the layered-structure shielding film. Therefore, it is concluded that the laminated structure of the shielding film, which is identical to the internal laminated structure of the abalone shell, expands the impact area of incident radiation and attenuates the energy intensity, thereby improving the medical-radiation-shielding performance.

Mechanical Recycling and Its Effects on the Physical and Mechanical Properties of Polyamides

The aim of this study is to investigate the impact of mechanical recycling on the physical and mechanical properties of recycled polyamide 6 (PA6) and polyamide 66 (PA66) in relation to their microstructures. Both PA6 and PA66 raw materials were reprocessed six times, and the changes in their properties were investigated as a function of recycling number. Until the sixth round of recycling, slight changes in the mechanical properties were detected, except for the percentage of elongation. For the physical properties, the change in both flexural strength and Young's modulus followed a decreasing trend, while the trend in terms of elongation showed an increase. Microscopic analysis was performed on virgin and recycled specimens, showing that imperfections in the crystalline regions of polyamide 6 increased as the number of cycles increased.

Study of the Structural, Morphological, Strength and Shielding Properties of CuBi2O4 Films Obtained by Electrochemical Synthesis

In this research, the formation processes of CuBi2O4 films were examined using atomic force microscopy, energy dispersive analysis and X-ray diffraction analysis methods. The films were synthesized through electrochemical deposition from sulfuric acid solutions at a potential difference of 3.5 V. The duration of film growth was set to between 10 and 90 min to assess the possibility of controlled film growth and preserve the stability of their structural properties during growth over an extended period. An analysis of the data obtained by X-ray diffraction revealed that the resulting film samples are highly ordered structures with a tetragonal CuBi2O4 phase. The results of the connection between the thickness of CuBi2O4 films and strength properties depending on the time of film deposition were obtained. The results of the shielding efficiency of low-energy γ-quanta using CuBi2O4 films were obtained.

Microstructural and Radioactive Shielding Analyses of Alumix-231 and Alumix-231 Reinforced with B4C/SiC/Al2O3 Particles Produced through Hot Pressing

Al2O3, SiC, and B4C (10%) particle-reinforced Alumix-231 matrix composites and nonreinforced Alumix-231 blocks were produced by pressing under uniaxial pressure using the powder metallurgy method. The Archimedes density of the produced samples was analyzed using microstructures (SEM and EDS), powder size analysis, and theoretical (PSD software) and experimental methods (Co-60 and Cs-137 radiation sources). As a result of the theoretical and experimental calculations, the Alumix-231 + 10% B4C composite material showed the lowest shielding feature against γ radiation, while the Alumix-231 + 10% Al2O3 composite material showed the highest shielding feature.

Transition Metal Borides for All-in-One Radiation Shielding

All-in-one radiation shielding is an emerging concept in developing new-generation radiation protection materials since various forms of ionizing radiation, such as neutrons and gamma rays, can occur simultaneously. In this study, we examine the ability of transition metal borides to attenuate both photon and particle radiation. Specifically, fourteen different transition metal borides (including inner transition metal borides) are selected for examination based on their thermodynamic stabilities, molecular weights, and neutron capture cross-sections of the elements they contain. Radiation shielding characteristics of the transition metal borides are computationally investigated using Phy-X/PSD, EpiXS and NGCal software. The gamma-ray shielding capabilities of the transition metal borides are evaluated in terms of the mass attenuation coefficient (μm), the linear attenuation coefficient (µ), the effective atomic number (Zeff), the half-value layer (HVL), the tenth-value layer (TVL), and the mean free path (MFP). The mass and linear attenuation factors are identified for thermal and fast neutrons at energies of 0.025 eV and 4 MeV, respectively. Moreover, the fast neutron removal cross-sections (∑R) of the transition metal borides are calculated to assess their neutron shielding abilities. The results revealed that borides of transition metals with a high atomic number, such as Re, W, and Ta, possess outstanding gamma shielding performance. At 4 MeV photon energy, the half-value layers of ReB2 and WB2 compounds were found as 1.38 cm and 1.43 cm, respectively. Most notably, these HVL values are lower than the HVL value of toxic Pb (1.45 cm at 4 MeV), which is one of the conventional radiation shielding materials. On the other hand, SmB6 and DyB6 demonstrated exceptional neutron attenuation for thermal and fast neutrons due to the high neutron capture cross-sections of Sm, Dy, and B. The outcomes of this study reveal that transition metal borides can be suitable candidates for shielding against mixed neutron and gamma radiation.

Novel slag/natural rubber composite as flexible material for protecting workers against radiation hazards

This work is an attempt to employ the electric arc furnace (EAF) slag as a by-product material to develop an alternative and environmentally friendly material for gamma-radiation protection applications such as in medical and industrial areas. For this purpose, different concentrations of micro-sized EAF slag (0, 20, 40, 60, 80, 100, 500, and 800 phr) were incorporated as fillers in the natural rubber (NR) matrix to produce the shielding composites. In addition, nano-sized EAF slag particles were prepared by using a high-energy ball milling technique to investigate the effect of particle size on the gamma-radiation shielding properties. The synthesized micro and nano EAF/NR composites were tested as protective materials against gamma-radiation by employing NaI(Tl) scintillation detector and standard radioactive point sources (152Eu, 137Cs, 133Ba, and 60Co). Different shielding parameters such as linear and mass attenuation coefficient, half value layer (HVL), tenth value layer, mean free path, effective atomic number (Zeff), and effective electron density (Neff) were determined to assess the radiation shielding capability of the EAF/NR composites. Furthermore, equivalent atomic number (Zeq) and the exposure buildup factor values for photon energy in the range from 0.015 to 15 MeV were also computed by Geometric Progression method. The experimental results of micro EAF/NR composites showed that at 121.78 keV, EAF0 composite (without EAF slag content) had the lowest μ value of 0.1695 cm-1, while the EAF800 composite (which was loaded with 800 phr of micro EAF slag) had the highest μ value of 0.2939 cm-1 at the same energy, which in turn decreases the HVL from 4.09 to 2.36 cm, respectively. Therefore, increasing the filler weight fractions of EAF slag in the NR matrix, increases the shielding properties of the composites. Moreover, the NR composite reinforced with 800 phr of nano EAF slag has better gamma-radiation shielding efficiency compared to that filled with 800 phr of micro EAF slag. The success of this work was to prepare a flexible, lightweight, low-cost, and lead-free material with better shielding capability.

Circular Production, Designing, and Mechanical Testing of Polypropylene-Based Reinforced Composite Materials: Statistical Analysis for Potential Automotive and Nuclear Applications

The circularity of polymer waste is an emerging field of research in Europe. In the present research, the thermal, surface, mechanical, and tribological properties of polypropylene (PP)-based composite produced by injection molding were studied. The pure PP matrix was reinforced with 10, 30, and 40% wt. of pure cotton, synthetic polyester, and polyethylene terephthalate post-consumer fibers using a combination of direct extrusion and injection molding techniques. Results indicate that PP-PCPESF-10% wt. exhibits the highest value of tensile strength (29 MPa). However, the values of tensile and flexural strain were lowered with an increase in fiber content due to the presence of micro-defects. Similarly, the values of modulus of elasticity, flexural modulus, flexural strength, and impact energy were enhanced due to an increase in the amount of fiber. The PP-PCCF-40% wt. shows the highest values of flexural constant (2780 MPa) and strength (57 MPa). Additionally, the increase in fiber loadings is directly proportional to the creation of micro-defects, surface roughness, abrasive wear, coefficient of friction, and erosive wear. The lowest average absolute arithmetic surface roughness value (Ra) of PP and PP-PCCF, 10% wt., were 0.19 µm and 0.28 µm. The lowest abrasive wear value of 3.09 × 10-6 mm3/Nm was found for pure PP. The erosive wear value (35 mm3/kg) of PP-PCCF 40% wt. composite material was 2 to 17 times higher than all other composite materials. Finally, the single-step analysis of variance predicts reasonable results in terms of the p-values of each composite material for commercial applications.

Multicomponent X-ray Shielding Using Sulfated Cerium Oxide and Bismuth Halide Composites

Lead is the most widely used X-ray-shielding material, but it is heavy (density ≈ 11.34 g/cm3) and toxic. Therefore, the replacement of Pb with lightweight, ecofriendly materials would be beneficial, and such materials would have applications in medicine, electronics, and aerospace engineering. However, the shielding ability of Pb-free materials is significantly lower than that of Pb itself. To maximize the radiation attenuation of non-Pb-based shielding materials, a high-attenuation cross-section, normal to the incoming X-ray direction, must be achieved. In this study, we developed efficient X-ray-shielding materials composed of sulfated cerium oxide (S-CeO2) and bismuth halides. Crucially, the materials are lightweight and mechanically flexible because of the absence of heavy metals (for example, Pb and W). Further, by pre-forming the doped metal oxide as a porous sponge matrix, and then incorporating the bismuth halides into the porous matrix, uniform, compact, and intimate composites with a high-attenuation cross-section were achieved. Owing to the synergetic effect of the doped metal oxide and bismuth halides, the resultant thin (approximately 3 mm) and lightweight (0.85 g·cm-3) composite achieved an excellent X-ray-shielding rate of approximately 92% at 60 kV, one of the highest values reported for non-heavy-metal shielding materials.

Advances in Organic-Inorganic Hybrid Latex Particles via In Situ Emulsion Polymerization

Hybrid latex particles combine the unique properties of inorganic nano/micro particles with the inherent properties of polymers, exhibiting tremendous potential for a variety of applications. Recent years have witnessed an increased interest in the design and preparation of hybrid latex particles with well-defined size, structure and morphology. Due to its simplicity, versatility and environmental friendliness, the in situ (Pickering) emulsion polymerization has been demonstrated to be a powerful approach for the large-scale preparation of hybrid latex particles. In this review, the strategies and applications of in situ (Pickering) emulsion polymerization for the preparation of hybrid latex particles are systematically summarized. A particular focus is placed on the strategies for the preparation of hybrid latex particles with enhanced properties and well-defined core-shell, yolk-shell, multinuclear, raspberry-like, dumbbell-shaped, multipod-like or armored morphologies. We hope that the considerable advances, examples and principles presented in this review can motivate future contributions to provide a deeper understanding of current preparation technologies, develop new processes, and enable further exploitation of hybrid latex particles with outstanding characteristics and properties.

Practical guidance to reduce radiation exposure in electrophysiology applying ultra low-dose protocols: a European Heart Rhythm Association review

Interventional electrophysiology offers a great variety of treatment options to patients suffering from symptomatic cardiac arrhythmia. Catheter ablation of supraventricular and ventricular tachycardia has globally evolved a cornerstone in modern arrhythmia management. Complex interventional electrophysiological procedures engaging multiple ablation tools have been developed over the past decades. Fluoroscopy enabled interventional electrophysiologist throughout the years to gain profound knowledge on intracardiac anatomy and catheter movement inside the cardiac cavities and hence develop specific ablation approaches. However, the application of X-ray technologies imposes serious health risks to patients and operators. To reduce the use of fluoroscopy during interventional electrophysiological procedures to the possibly lowest degree and to establish an optimal protection of patients and operators in cases of fluoroscopy is the main goal of modern radiation management. The present manuscript gives an overview of possible strategies of fluoroscopy reduction and specific radiation protection strategies.

Recent Progress in Gd-Containing Materials for Neutron Shielding Applications: A Review

With the rising demand for nuclear energy, the storage/transportation of radioactive nuclear by-products are critical safety issues for humans and the environment. These by-products are closely related to various nuclear radiations. In particular, neutron radiation requires specific protection by neutron shielding materials due to its high penetrating ability to cause irradiation damage. Herein, a basic overview of neutron shielding is presented. Since gadolinium (Gd) has the largest thermal neutron capture cross-section among various neutron absorbing elements, it is an ideal neutron absorber for shielding applications. In the last two decades, there have been many newly developed Gd-containing (i.e., inorganic nonmetallic-based, polymer-based, and metallic-based) shielding materials developed to attenuate and absorb the incident neutrons. On this basis, we present a comprehensive review of the design, processing methods, microstructure characteristics, mechanical properties, and neutron shielding performance of these materials in each category. Furthermore, current challenges for the development and application of shielding materials are discussed. Finally, the potential research directions are highlighted in this rapidly developing field.

Synthesis and Investigation of the Properties of Biphasic Hybrid Composites Based on Bentonite, Copper Hexacyanoferrate, Acrylamide and Acrylic Acid Hydrogel

This article presents a study of the synthesis and characterization of new biphasic hybrid composite materials consisting of intercalated complexes (ICC) of natural mineral bentonite with copper hexaferrocyanide (phase I), which are incorporated into the bulk of the polymer matrix (phase II). It has been established that the sequential modification of bentonite with copper hexaferrocyanide and introduction of acrylamide and acrylic acid cross-linked copolymers into its volume by means of in situ polymerization promote the formation of a heterogeneous porous structure in the resulting hybrid material. The sorption abilities of prepared hybrid composite toward radionuclides of liquid radioactive waste (LRW) have been studied, and the mechanism for binding radionuclide metal ions with the components of the hybrid composition have been described.

Investigation on Physico Chemical and X-ray Shielding Performance of Zinc Doped Nano-WO3 Epoxy Composite for Light Weight Lead Free Aprons

This report addresses a way to reduce the usage of highly toxic lead in diagnostic X-ray shielding by developing a cost-effective, eco-friendly nano-tungsten trioxide (WO₃) epoxy composite for low-weight aprons. Zinc (Zn)-doped WO₃ nanoparticles of 20 to 400 nm were synthesized by an inexpensive and scalable chemical acid-precipitation method. The prepared nanoparticles were subjected to X-ray diffraction, Raman spectroscopy, UV-visible spectroscopy, photoluminescence, high-resolution-transmission electron microscope, scanning electron microscope, and the results showed that doping plays a critical role in influencing the physico-chemical properties. The prepared nanoparticles were used as shielding material in this study, which were dispersed in a non-water soluble durable epoxy resin polymer matrix and the dispersed materials were coated over a rexine cloth using the drop-casting method. The X-ray shielding performance was evaluated by estimating the linear attenuation coefficient (μ), mass attenuation coefficient (μ_m), half value layer (HVL), and X-ray percentage of attenuation. Overall, an improvement in X-ray attenuation in the range of 40-100 kVp was observed for the undoped WO₃ nanoparticles and Zn-doped WO₃ nanoparticles, which was nearly equal to lead oxide-based aprons (reference material). At 40 kVp, the percentage of attenuation of 2% Zn doped WO₃ was 97% which was better than that of other prepared aprons. This study proves that 2% Zn doped WO₃ epoxy composite yields a better particle size distribution, μ_m, and lower HVL value and hence it can be a convenient lead free X-ray shielding apron.

Assessment of X-ray shielding properties of polystyrene incorporated with different nano-sizes of PbO

PbO (lead oxide) particles with different sizes were incorporated into polystyrene (PS) with various weight fractions (0, 10, 15, 25, 35%). These novel PS/PbO nano-composites were produced by roll mill mixing and compressing molding techniques and then investigated for radiation attenuation of X-rays (N-series/ISO 4037) typically used in radiology. Properties of the PbO particles were studied by X-ray diffraction (XRD). Filler dispersion and elemental composition of the prepared nano-composites were characterized using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS), revealing better filler distribution and fewer agglomerations with smaller PbO particle size. Linear and mass attenuation coefficients (μ and μ_m), total molecular and atomic cross-sections (σ_mol and σ_atm), as well as effective atomic number and electron density (Z_eff and N_eff), were calculated for the energy range N40 to N200. The influence of PbO weight percentage on the enhancement of the shielding parameters of the nano-composites was expected; however, the effect of PbO particle size was surprising. Linear and mass attenuation coefficients for PS/PbO composites increased gradually with increasing PbO concentrations, and composites with a small size of nanoparticles showed best performance. In addition, increasing PbO concentration raised the effective atomic number Z_eff of the composite. Hence, the electron density N_eff increased, which provided a higher total interaction cross-section of X-rays with the composites. Maximum radiation shielding was observed for PS/PbO(B). It is concluded that this material might be used in developping low-cost and lightweight X-ray shielding to be used in radiology.

Study of Prepared Lead-Free Polymer Nanocomposites for X- and Gamma-ray Shielding in Healthcare Applications

Polymer composites were synthesized via melt mixing for radiation shielding in the healthcare sector. A polymethyl-methacrylate (PMMA) matrix was filled with Bi₂O₃ nanoparticles at 10%, 20%, 30%, and 40% weight percentages. The characterization of nanocomposites included their morphological, structural, and thermal properties, achieved using SEM, XRD, and TGA, respectively. The shielding properties for all synthesized samples including pristine PMMA were measured with gamma spectrometry using a NaI (Tl) scintillator detector spanning a wide range of energies and using different radioisotopes, namely Am-241 (59.6 keV), Co-57 (122.2 keV), Ra-226 (242.0), Ba-133 (80.99 and 356.02 keV), Cs-137 (661.6 keV), and Co-60 (1173.2 and 1332.5 keV). A substantial increase in the mass attenuation coefficients was obtained at low and medium energies as the filler weight percentage increased, with minor variations at higher gamma energies (1173 and 1332 keV). The mass attenuation coefficient decreased with increasing energy except under 122 keV gamma rays due to the K-absorption edge of bismuth (90.5 keV). At 40% loading of Bi₂O_3, the mass attenuation coefficient for the cesium ¹³⁷Cs gamma line at 662 keV reached the corresponding value for the toxic heavy element lead. The synthesized PMMA-Bi₂O₃ nanocomposites proved to be highly effective, lead-free, safe, and lightweight shielding materials for X- and gamma rays within a wide energy range (<59 keV to 1332 keV), making them of interest for healthcare applications.

A comparative neutron and gamma-ray radiation shielding investigation of molybdenum and boron filled polymer composites

This work presents a detailed radiation shielding study for polymer composites filled with Boron and Molybdenum additives. The chosen novel polymer composites were produced at different percentages of the additive materials to provide a proper evaluation of their neutron and gamma-ray attenuation abilities. The effect of additive particle size on the shielding characteristics was further investigated. On the gamma-ray side, simulation, theoretical and experimental evaluations were performed in a wide range of photon energies varying from 59.5 keV to 1332.5 keV with help of MC simulations (GEANT4 and FLUKA), WinXCOM code, a High Purity Germanium Detector, respectively. A remarkable consistency was reported between them. On the neutron shielding side, the prepared samples produced with nano and micron particle size additives were additionally examined by providing fast neutron removal cross-section (Σ_R) and the simulated neutron transmissions through the prepared samples. The samples filled with nano sized particles show better shielding capability than the one filled with micron sized particles. In other words, a new polymer shielding material that does not contain toxic content is introduced: the sample codded N-B0Mo50 exhibits superior radiation attenuation.

United atom and coarse grained models for crosslinked polydimethylsiloxane with applications to the rheology of silicone fluids

Siloxane systems consisting primarily of polydimethylsiloxane (PDMS) are versatile, multifaceted materials that play a key role in diverse applications. However, open questions exist regarding the correlation between their varied atomic-level properties and observed macroscale features. To this effect, we have created a systematic workflow to determine coarse-grained simulation models for crosslinked PDMS in order to further elucidate the effects of network changes on the system's rheological properties below the gel point. Our approach leverages a fine-grained united atom model for linear PDMS, which we extend to include crosslinking terms, and applies iterative Boltzmann inversion to obtain a coarse-grain "bead-spring-type" model. We then perform extensive molecular dynamics simulations to explore the effect of crosslinking on the rheology of silicone fluids, where we compute systematic increases in both density and shear viscosity that compare favorably to experiments that we conduct here. The kinematic viscosity of partially crosslinked fluids follows an empirical linear relationship that is surprisingly consistent with Rouse theory, which was originally derived for systems comprised of a uniform distribution of linear chains. The models developed here serve to enable quantitative bottom-up predictions for curing- and age-induced effects on macroscale rheological properties, allowing for accurate prediction of material properties based on fundamental chemical data.

Preparation and characterization of tin chloride-based polymeric composite for gamma shielding applications

Thin films of Poly (ethylene-co-vinyl acetate)/tin chloride different weight (w/w) ratios were prepared using a spin-coating method. The diameter, height, grain size, and other morphological and structural features of the prepared thin films were studied using atomic force microscope (AFM) system. Moreover, the maximum surface roughness and average diameter of the prepared thin films were reported to weight ratio of 0.3%Sn Also, the shielding properties of adding tin chloride inside the polymer matrix were investigated. In addition, the impact of adding the tin-dopant to the targeted polymer on the attenuation parameters, including the linear attenuation coefficient (μ), half-value layer (HVL), screening ratios, and the mean free path, were theoretically calculated. The results show that the properties of the prepared thin films can be improved significantly by introducing a small amount of tin chloride to the host polymer promoting the crystallinity of the produced material and enhancing the shielding property for gamma-rays. The better linear attenuation coefficient of the produced thin films was reported to the weight ratio of 0.3% Sn. The produced Poly (ethylene-co-vinyl acetate)/tin chloride thin films can be suggested as one of the significant shielding materials to be used in a wide range of applications in the field of radiation.

Stepwise Crystallization of Millimeter Scale Thorium Cluster Single Crystals as a Bifunctional Platform for X-ray Detection and Shielding

Monitoring and shielding of X-ray radiation are of paramount importance across diverse fields. However, they are frequently realized in separate protocols and a single material integrating both functions remained elusive. Herein, a hexanuclear cluster [Th₆ (µ₃ -OH)₄ (µ₃ -O)₄ (H₂ O)₆ ](pba)₆ (HCOO)₆ (Th-pba-0D) incorporating high-Z thorium cations and 3-(pyridin-4-yl)benzoate ligands that can function as a brand-new dual-module platform for visible detection and efficient shielding of ionizing radiation is demonstrated. Th-pba-0D exhibits rather unique reversible radiochromism upon alternating X-ray and UV irradiation. Moreover, the millimeter scale crystal size of Th-pba-0D renders the penetration depth of X-ray visible to naked eye and leads to the unearthing of its high X-ray attenuation efficiency. Indeed, the shielding efficacy of Th-pba-0D is comparable to that of lead glass containing 40% PbO, and a Th-pba-0D pellet with a thickness of merely 1.2 mm can shield 99.73% X-ray (16 keV). These studies portend the possible utilization of thorium-bearing materials as a bifunctional platform for radiation detection and shielding.

Non-Toxic and Flexible Radiation-Shielding Composites Based on Natural Rubber Containing Elemental W Fillers for Efficient Shielding against X/γ-rays

Conventional radiation-shielding composites usually contain lead, which results in high toxicity and poor portability. Tungsten (W) is an ideal radiation-shielding element that can replace lead due to its high atomic number and non-toxicity. In this work, radiation-shielding composites were prepared using natural rubber (NR) as a matrix and three different particle size powders, namely W, WO3 and WC, as fillers. The results show that, for X-rays, the linear attenuation coefficient of radiation-shielding composites based on natural rubber containing WC with a particle size of 50 μm (50 WC/NR) is 27.005 cm−1 at an X-ray tube voltage of 40 kV, which is more than 14 times the linear attenuation coefficient of NR. For γ-rays, a linear attenuation coefficient of 50 WC/NR achieves 8.320 cm−1 at 81 keV, which is over 55 times the linear attenuation coefficient of NR. In addition, 50 WC/NR had the highest elongation at break at 548.989% and had the lowest hardness at 62 HA. In summary, 50 WC/NR can be used as an alternative to traditional radiation-shielding materials containing lead and has wide application prospects.

Investigation of radiation protective features of azadispiro derivatives and their genotoxic potential with Ames/Salmonella test system

PURPOSE

Five different types of synthesized azadispiro derivatives have been analyzed for radiation absorption capacity and determined their potential to be exploited as substances for a drug to be developed against radiation has been investigated.

MATERIAL AND METHODS

Fast neutron attenuation parameters like the effective mean free path, half-value layer (HVL), removal cross-sections, and neutron transmission number were found with the Monte Carlo simulation Geometry And Tracking (GEANT4) code. Gamma radiation absorption parameters, such as effective atom number (Z_eff), mean free path (MFP), mass attenuation coefficient (MAC), and half-value layer (HVL) were theoretically determined with WinXCom software. Besides, the exposure build-up factor (EBF) was calculated by using GP fitting parameters. Neutron absorption dose rate was experimentally calculated with ²⁴¹Am-Be fast neutron source which has 4.5 MeV of energy, 74 GBq activity, and portative BF₃ neutron detector. Ames/Salmonella test systems were used for the genotoxic potentials of the azadispiro derivatives.

RESULTS AND CONCLUSIONS

Experimental and theoretical results were checked with paraffin and High-Density Polyethylene. The results showed that Azadispiro derivatives have neutron radiation absorption capability close to paraffin and High-Density Polyethylene. The gamma radiation absorption properties for azadispiro derivatives have been investigated, and it has been observed that these materials can absorb gamma radiation. Ames/Salmonella assay was used to examine whether the derivatives had a genotoxic effect probability or not. The results showed that these derivatives were genotoxic and safe at test doses (up to 5 mM). Consequently, it has been understood that these azadispiro derivatives can be used as active and genotoxic safety ingredients in the production of a protective drug against both neutrons and gamma rays.

Metal-halide perovskites for high-efficiency radiation shielding applications

The ionizing radiation possesses extremely strong penetration capability, which poses serious risk on the health of the human body and jeopardize electronics. Here the authors demonstrate that MAPbI₃/epoxy composites prepared by a simple method show high radiation shielding performance.