High-energy Electron Beam Irradiation Research Articles

Acute toxicity and genotoxicity evaluation of irradiated ophiopogonis radix at 25 kGy with electron beam

As concerned about the potential risks of irradiated Ophiopogonis Radix (IOR) at a high radiation level (25 kGy) by high-energy electron beam irradiation, this study evaluated oral acute toxicity and genotoxicity of IOR. Moisture, total ash, water-soluble extracts, and ruscogenin content in IOR meet the requirement of Ophiopogonis Radix described in the Chinese Pharmacopoeia. When the mice received by oral 21.5 g/kg BW administration of IOR in the acute toxicity test, neither mortality nor any other abnormal general clinical signs were found within 14 days, except that 10% of mice suffered from diarrhea on day 1, which disappeared and returned to normal on day 4. The acute toxicity test indicated the LD50 of IOR was higher than 21.5 g/kg BW. Ames test showed no dose-dependent increase in TA97a, TA98, TA100, TA102, and TA1535 strains with or without rat liver microsomal enzyme mixture (S9) metabolic activation, at a quantity range of 50–5000 μg IOR. Mouse micronucleus test of bone marrow cells demonstrated no significant increase in the frequencies of micronucleated polychromatic erythrocytes (MN PCEs) among each IOR dose. Mouse sperm abnormality test showed that there was no evidence of the potential to induce sperm malformation with oral administration at doses of 2.5, 5.0, and 10.0 g/kg BW. Overall, the acute toxicity or genotoxicity of IOR were not observed, indicating that IOR at 25 kGy with a high-energy electron beam is toxicologically safe.

Effects of High-Energy Electron Beam Irradiation on The Structure, Composition and Morphological Properties of Graphene Nanoplatelet Films

This work demonstrated the effects of 1.2 GeV high-energy electron beam irradiation on a few-layers of graphene (FLG) and multi-layer graphene (MLG) films grown via an in-house hot wire chemical vapour deposition (HWCVD) system. The FLG and MLG films were grown on highly doped n-type c-Si (100) substrates which were pre-treated using argon plasma (50 W) for 1 min and 10 min, respectively. The as-prepared samples were then irradiated using a 1.2 GeV high-energy electron beam with a dosage of 1.2 × 109 e-/cm2 at atmospheric and room temperature ambient conditions. The effects of the irradiation-mediated defects on the carbon lattice structure of both graphene samples were validated from the decreased sp2 C=C carbon content, and the increase in the adventitious carbon contamination C-O-C content. Raman results showed an elevation of the ID/IG ratio and blue-shift of the 2D and G band peaks for both the irradiated samples, which validated the mediated defects due to the dislocation of carbon atoms in the graphene sheets. The blue-shifted of 2D and G peaks were much more significant in the MLG than FLG which may indicate a better self-reconstructing property for the MLG atomic network, compared to the FLG. The stability of the films against high-energy electron beam irradiation was validated by their conductivity and surface topography. In conclusion, HWCVD grown graphene nanoplatelet films have high potential for graphene-based high-energy charged particle detectors.

In-situ free-standing inorganic 2D Cs2PbI2Cl2 nanosheets for efficient self-powered photodetectors with carbon electrode

Inorganic two-dimensional (2D) perovskites possess excellent thermal stability and high charge mobility, making them an attractive choice for stable optoelectronic devices such as photodetectors (PDs). The formation of an appropriate inorganic 2D perovskite structure is of great importance to efficient PDs, especially to that of planar self-powered photovoltaic PDs featuring perpendicular charge transport channels. Herein, we implemented morphological engineering on wide bandgap inorganic 2D perovskite, Cs2PbI2Cl2, demonstrating a successful preparation of in-situ free-standing nanosheets structure with proper charge channels for photovoltaic type self-powered PDs. Compared with its counterpart with a nanoblock morphology, the 2D nanosheet Cs2PbI2Cl2 film exhibits enhanced charge mobility and purified Ruddlesden-Popper phase that can withstand high-energy electron beam radiation, accelerated thermal aging and long-term shelf storage. Sandwiching Cs2PbI2Cl2 nanosheet film in between tin oxide (SnO2) and polythiophene (P3HT) as electron and hole acceptors, respectively, the constructed photovoltaic type structure exhibits effective dissociation of excitons at the cascade type-II interface. The nanosheets enable lower dark current and more efficient charge collection than the nanoblock structure. As a result, the self-powered photodetectors with 2D Cs2PbI2Cl2 nanosheets deliver an outstanding responsivity of 698 mW/cm2 and a detectivity of 8.6×1012 Jones. The stable PDs can be applied to monitor ultraviolet irradiation in real outdoor conditions. Our work demonstrates the significant role of morphology tuning of 2D inorganic perovskite in stable, cost-effective and efficient photodetectors.

Change in charge state of NV center caused by monovacancy formation

Effects of monovacancy formation on the charge states of nitrogen vacancy (NV) centers in nitrogen-doped diamond single crystal were investigated. Monovacancies are formed using high-energy electron beam irradiation. The ratio of the concentration of negatively charged nitrogen vacancy (NV−) centers to the total concentration of NV− centers and neutral nitrogen vacancy (NV0) centers decreases with increased concentration of monovacancies. This decrease occurs because of the reduction of the concentration of neutral substitutional nitrogen [Ns0] donating electrons to NV0 centers. Findings indicate that numerous electrons of Ns0 are transferred preferentially to monovacancies, not to NV0 centers.

A multiparametric study on the behavior of mesoporous silica under electron irradiation

Grafted mesoporous silica is believed to be a candidate for the decontamination of radioactive effluents and the final storage of radionuclides. Under this condition, silica is subjected to continuous electron irradiation due to beta decay of radionuclides. This paper examined two mesoporous silica (SBA-15 and MCM-41) under high-energy electron beam irradiation (0.6 MeV <E < 2.4 MeV). The results showed that the pore structure of both mesoporous silica pellets shrank for all the samples (with 40 % < ΔVpores < 60 % at 8 × 1018 e-/cm2), while no significant damage was observed in the amorphous silica network. The main reason for the structural changes was attributed to electron beam radiation-induced fluidization. Additional experiments conducted with numerous incident electron energies provided more detailed support, confirming that the radiolytic process was the primary cause of fluidization. These findings contribute to a better understanding of electron-irradiation-induced damage and may lead to novel approaches for handling radionuclides with mesoporous materials.

Insight into the molecular mechanism underlying the enhancement of antioxidant activity in ovalbumin by high-energy electron beam irradiation

The effects of high-energy electron beam irradiation (HE-EBI) at various doses (0, 25, 50, 75, and 100 kGy) on the antioxidant activity of ovalbumin (OVA) were studied, and the molecular mechanism was investigated. The results showed that the antioxidant activity of HE-EBI-treated OVA was significantly enhanced in a dose-dependent manner. The irradiated OVA structure gradually unfolded to form a “honeycomb” structure, exposing the buried hydrophobic and free sulfhydryl groups inside the molecule. Two oxidation sites (M35 and T170), adjacent to the antioxidant peptide were identified by mass spectrometry, possibly exposing the antioxidant peptide through structural deconvolution. In addition, aspartic residues generated dicarbonyl compound under high-energy electron beam stress, and its accumulation further enhanced the antioxidant activity. Conclusively, HE-EBI can enhance the antioxidant activity of OVA through ionization effects, providing valuable information for the potential application of HE-EBI in the food industry.

Synthesis and characterization of electron beam irradiated glutinous rice husk-derived biochar and activated carbon for aqueous electrochemical capacitors

Glutinous rice husk, an abundant agricultural biowaste in Thailand, was pretreated with high energy electron beam irradiation (EBI) at doses of 500 kGy, 1000 kGy, and 1500 kGy prior to fabrication into biochar by carbonization at 500℃ under nitrogen atmosphere. The biochar was then treated with KOH and subsequently heated at 800℃, yielding activated carbon (GAC). The physical, chemical, and electrochemical properties of the as-received biochar (GB) and activated carbon (GAC) were investigated. Scanning electron microscopic images (SEM) suggested that biochar irradiated with 1500 kGy (GB-1500) has the highest porosity compared to the other samples. The electrochemical properties of GB and GAC in 3 M H2SO4 using a three-electrode system indicated that EBI affects the electrochemical performance of the material. The specific capacitance of GB-1500 (6.15 F·g-1 at 0.05 A·g-1) is higher than that of the as-received biochar, and the improved performance of the former is potentially due to the formation of structural defects upon irradiation. Finally, we observed that the specific capacitances of the GAC were much higher than those of their corresponding GB with the same irradiation doses, and the capacitances of the GAC decrease with increasing EBI dose.

Urea-Straw-Starch Fertilizer with Tunable Water- and Nutrient-Retaining Properties Assisted by High-Energy Electron-Beam Irradiation.

A novel type of water- and nutrient-retaining fertilizer (WNRF) was prepared by mixing, melting, and extruding high-energy electron-beam (HEEB)-irradiated corn straw, urea, and starch. HEEB irradiation technique effectively killed pathogenic microorganisms in straw and further improved the adsorption and binding capacity of straw to urea and water. Compared to nonirradiated HEEB samples, the optimal WNRF improved the water retention rate by 25.63%, the migrate-to-surface loss control rate by 60.2%, and the leaching loss control rate by 34.71%, respectively. Thus, it effectively facilitated the growth of pak choi with a 24% increase in the dry matter weight of the shoot. This work provides a promising approach to improve water and nutrient availability in arid and semi-arid regions and to promote the efficient utilization of straw resources.

One-pot production of multiple stacked lithium-ion batteries with gel polymer electrolyte through high-energy electron beam irradiation

Gel polymer electrolytes (GPEs) have garnered considerable interest in lithium-ion battery (LIB) applications owing to their ability to combine the desirable attributes of liquid electrolytes (e.g., high conductivity) with the stability of solid electrolytes. They are fabricated by immobilizing the liquid electrolyte within a polymer matrix. Notably, the utilization of high-energy electron beam (EB) technology is a promising approach for the in situ preparation of GPEs, which establishes the need for an initiator or thermal treatment. The simultaneous generation of multiple GPEs via EB irradiation confers significant economic advantages. This study reports the simultaneous production of GPEs from multiple-stacked LIBs through a single-step irradiation of high-energy EB. In particular, we used trimethylolpropane propoxylate triacrylate with a trifunctional acrylate ester as the cross-linker for the GPE, and investigated the effect of the EB dose on the properties of the individual cell components and its electrochemical performance to determine the optimal EB dose of 15 kGy. Thereafter, we tested the penetration of EB irradiation on 0.5-Ah-level pouch cells. As observed, an EB of ∼ 15 kGy could penetrate seven pouch cells, which displayed stable cell performances when fabricated using simultaneous EB irradiation. Overall, the results demonstrated the economic feasibility of the proposed method owing to its high productivity on a commercial scale.

Atomic-scale in situ observation of electron beam and heat induced crystallization of Ge nanoparticles and transformation of Ag@Ge core-shell nanocrystals.

Crystallization of amorphous materials by thermal annealing has been investigated for numerous applications in the fields of nanotechnology, such as thin-film transistors and thermoelectric devices. The phase transition and shape evolution of amorphous germanium (Ge) and Ag@Ge core-shell nanoparticles with average diameters of 10 and 12nm, respectively, were investigated by high-energy electron beam irradiation and in situ heating within a transmission electron microscope. The transition of a single Ge amorphous nanoparticle to the crystalline diamond cubic structure at the atomic scale was clearly demonstrated. Depending on the heating temperature, a hollow Ge structure can be maintained or transformed into a solid Ge nanocrystal through a diffusive process during the amorphous to crystalline phase transition. Selected area diffraction patterns were obtained to confirm the crystallization process. In addition, the thermal stability of Ag@Ge core-shell nanoparticles with an average core of 7.4 and a 2.1nm Ge shell was studied by applying the same beam conditions and temperatures. The results show that at a moderate temperature (e.g., 385°C), the amorphous Ge shell can completely crystallize while maintaining the well-defined core-shell structure, while at a high temperature (e.g., 545°C), the high thermal energy enables a freely diffusive process of both Ag and Ge atoms on the carbon support film and leads to transformation into a phase segregated Ag-Ge Janus nanoparticle with a clear interface between the Ag and Ge domains. This study provides a protocol as well as insight into the thermal stability and strain relief mechanism of complex nanostructures at the single nanoparticle level with atomic resolution.

Study on Silicone Rubber Composite Insulator Modified by High-Energy Electron Beam Irradiation

The impact of high-energy electron beam irradiation on silicone rubber composite insulator is investigated in this article. It was discovered that as the irradiation dose increased, the related properties of silicone rubber increased first and then decreased, with the static contact angle increasing to 111.8°, the tensile strength increasing to 4.59 MPa, the tear strength increasing to 26.8 kN/m, and the crosslinking density increasing to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$7.09\times 10^{-{4}}$ </tex-math></inline-formula> mol/cm3, but the elongation decreasing. SEM observation revealed that silicone rubber was more compact after irradiation. attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS) studies revealed that when the irradiation dose increased, the irradiation of silicone rubber shifted from crosslinking to degradation, and a new Si(−O)4 structure formed. Considering comprehensive performances, 40–50 kGy is the optimal irradiation dose. This article can provide support for understanding the irradiation modification of silicone rubber materials for composite insulator and also guide the preparation method of new silicone rubber.

Studies on the effects of highenergy electron beam irradiation on the Mechanical properties of Magnesium hydroxide filled HDPE/Mg(OH)2/TCA-27 composites

The effect of irradiation electron beam at dose of 150 kGy,on the mechanical properties of&#x0D; high density polyethylene (HDPE) mixed with various amounts of magnesium hydroxide (Mg(OH)2) composites as filler have been studied here. It has been found that the highenergy electron beam irradiation has much effect on the mechanical properties of the&#x0D; HDPE/Mg(OH)2/TCA-27 composites. The tensile strength and elastic modulus are increased greater than the unirradiated ones. Meanwhile, the increasing content of the Mg(OH)2 in composites. The structure of the SEM of the unirradiated HDPE/ Mg(OH)2/TCA-27 shows poorly mechanical properties of compositeswhich are compared to irradiated ones. The Comparison of properties of composites filled with irradiated and unirradiated Magnesium hydroxide establishes than irradiated of Magnesium hydroxide which imparts better reinforcing properties than unirradiated filler of composites. The properties under consideration are tensile strength, (%) elongation at break, elastic modulus, hardness . Tensile strength isimproved by 6.67% , elastic modulus is improved by 42.86%, while hardness is improved by 0.85%, at ( 0.37 ) volume fraction .

Honeycomb-like MnO2/Biochar Catalyst Fabricated by High-Energy Electron Beam Irradiation for Degradation of Antibiotics in Swine Urine.

The modification of biochar is essential for the development of multifunctional biochar materials with enhanced remediation effects on contaminated water. In this work, a biochar-based microcatalyst with sunlight sensitivity was synthesized by a creative modification method that involved the rapid fabrication of MnO2 microspheres by high-energy electron beam (HEEB) irradiation, and loading them into corn straw-derived honeycomb-like KOH-modified biochar (MBC) to obtain a sunlight-sensitive microcatalyst (SSM). The honeycomb-like structure of MBC facilitated the improvement in MnO2 dispersion and photocatalytic property through confinement effect. The effects of photocatalyst dosage, initial chlortetracycline (CTC) concentration, solution pH, temperature and coexisting ions on the photocatalytic performance of SSM were systemically investigated. The results indicated that SSM could efficiently degrade CTC in water and swine urine under sunlight, and exhibited high stability against coexistence of urea, Cl- and SO42-. Moreover, SSM showed good reusability in regeneration studies. This work provides a novel method for degrading CTC with potential application prospect.

Enhancement of thermoelectric power factor in Cu2Se superionic conductor via high energy electron beam irradiation

The modification in the Cu2Se thermoelectric system by electron beam irradiation has been carried out in this work. Samples were prepared using the solid-state reaction technique. The prepared samples were irradiated with various energy dosages viz. 50, 100, and 150 kGy. XRD studies reveal that the synthesized samples crystallized in a monoclinic structure. The micro-hardness of the samples decreased with an increase in irradiation dosage. The sample irradiated at 100 kGy dose exhibits the lowest electrical resistivity, moderate Seebeck coefficient, and highest power factor.

Metal-Organic Framework@Metal Oxide Heterostructures Induced by Electron-Beam Radiation.

Metal organic frameworks (MOFs) are a distinct family of crystalline porous materials finding extensive applications. Their synthesis often requires elevated temperature and relatively long reaction time. We report here the first case of MOF synthesis activated by high-energy (1.5 MeV) electron beam radiation from a commercially available electron-accelerator. Using ZIF-8 as a representative for demonstration, this type of synthesis can be accomplished under ambient conditions within minutes, leading to energy consumption about two orders of magnitude lower than that of the solvothermal condition. Interestingly, by controlling the absorbed dose in the synthesis, the electron beam not only activates the formation reaction of ZIF-8, but also partially etches the material during the synthesis affording a hierarchical pore architecture and highly crystalline ZnO nanoparticles on the surface of ZIF-8. This gives rise to a new strategy to obtain MOF@metal oxide heterostructures, finding utilities in photocatalytic degradation of organic dyes.

In-situ preparation of gel polymer electrolytes in a fully-assembled lithium ion battery through deeply-penetrating high-energy electron beam irradiation

Several in-situ preparation methods of gel polymer electrolytes (GPEs) to develop long-lasting and safe lithium ion batteries (LIBs) recently have been reported. However, the reported in-situ methods still have technical gaps for practical industrial uses in terms of processing time, integrity with the current production line, and scalability. Here, we report an in-situ method to prepare crosslinked poly(vinylene carbonate-co-cyanoethyl acrylate) (PVCEA) GPEs using 10 MeV electron beam (EB) irradiation in a fully-assembled metallic housing LIB that can be processed in a short time without any initiator or thermal treatment. The successful in-situ formation of PVCEA GPEs was achieved at absorbed doses above 16 kGy (irradiation time of 56 s), leading to intimately integrated GPEs with the electrodes, while ensuring stable charge and discharge performance. The prepared PVCEA GPE exhibited a higher transference number (tLi+ = ca. 0.53) and a wider electrochemical operation window (up to 5.0 V) than those of a liquid electrolyte (LE), while providing good ionic conductivity (1.17 mS/cm at 20 °C). Furthermore, the PVCEA GPE-based LIB prepared at an optimized dose of 16 kGy showed comparable retention capacity of 83 % at 0.5C to the conventional LE-based LIB after 300 cycles at 25 °C, and more importantly, better cycling durability at elevated temperature of 60 °C in comparison to the LE-based LIB. This study suggests that the combination of radiation-sensitive precursor formulation and high-energy EB with high penetration ability can provide a promising solution for industrial production of high-performing and safe LIBs.

Inactivation of porcine epidemic diarrhea virus with electron beam irradiation under cold chain conditions.

The many instances of COVID-19 outbreaks suggest that cold chains are a possible route for the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, owing to the low temperatures of cold chains, which are normally below 0 °C, there are limited options for virus inactivation. Here, high-energy electron beam (E-beam) irradiation was used to inactivate porcine epidemic diarrhea virus (PEDV) under simulated cold chain conditions. This coronavirus was used as a surrogate for SARS-CoV-2. The possible mechanism by which high-energy E-beam irradiation inactivates PEDV was also explored. An irradiation dose of 10 kGy reduced the PEDV infectious viral titer by 1.68–1.76 log10TCIDL in the cold chain environment, suggesting that greater than 98.1% of PEDV was inactivated. E-beam irradiation at 5–30 kGy damaged the viral genomic RNA with an efficiency of 46.25%–92.11%. The integrity of the viral capsid was disrupted at 20 kGy. The rapid and effective inactivation of PEDV at temperatures below freezing indicates high-energy E-beam irradiation as a promising technology for disinfecting SARS-CoV-2 in cold chain logistics to limit the transmission of COVID-19.

Increasing the surface hydrophobicity of silicone rubber by electron beam irradiation in the presence of a glycerol layer

A cost-effective and scalable silicone rubber (SR) modification technology for increasing its surface hydrophobicity is urgently needed to enhance the stability of global power systems. In this work, an easily accessible method was developed to increase the surface hydrophobicity of silicone rubber, which was established by high-energy electron beam irradiation in the presence of a layer of glycerol. Although glycerol is a highly hydrophilic alcohol, the contact angle of silicone rubber can be surprisingly increased by 19.9% with the irradiation treatment of glycerol. Despite a high hydroxyl content being observed, a network structure formed on the silicone rubber surface is responsible for the increase in hydrophobicity. Control experiments and molecular dynamics (MD) simulations were also conducted to shed light on the underlying mechanism. This method has some intrinsic advantages, such as cost-effectiveness, easy operation and nontoxicity of glycerol; thus, it is expected to be applicable in large-scale industrial production and modification of silicone rubber.

Direct imaging of the disconnection climb mediated point defects absorption by a grain boundary

Grain boundaries (GBs) are considered as the effective sinks for point defects, which improve the radiation resistance of materials. However, the fundamental mechanisms of how the GBs absorb and annihilate point defects under irradiation are still not well understood at atomic scale. With the aid of the atomic resolution scanning transmission electron microscope, we experimentally investigate the atomistic mechanism of point defects absorption by a ∑31 GB in α-Al2O3 under high energy electron beam irradiation. It is shown that a disconnection pair is formed, during which all the Al atomic columns are tracked. We demonstrate that the formation of the disconnection pair is proceeded with disappearing of atomic columns in the GB core, which suggests that the GB absorbs vacancies. Such point defect absorption is attributed to the nucleation and climb motion of disconnections. These experimental results provide an atomistic understanding of how GBs improve the radiation resistance of materials.

Synthesis of a Cyclophosphazene Derivative Containing Multiple Cyano Groups for Electron-Beam Irradiated Flame-Retardant Materials

A cyclophosphazene derivative containing multiple cyano groups, denoted as hexa(4-cyanophenoxy)cyclotriphosphazene (CN-CP), was synthesized by a one-step nucleophilic substitution reaction for a phosphorus-nitrogen flame retardant. To meet the strict requirement of safe and environment-protective insulation materials, a series of composites based on low-density polyethylene-poly(ethylene-co-vinyl acetate) containing CN-CP/Mg(OH)2/Al(OH)3 organic-inorganic synergistic flame retardants was fabricated. High-energy electron beam irradiation was subsequently applied to obtain a halogen-free flame-retardant crosslinked system. The relationship between crosslinking degree and irradiation dose was studied, and crosslinking degrees ranging within 63–85% were obtained under 100–190 kGy. Furthermore, the effects of CN-CP filler and irradiation dose on the properties of the composites were carefully investigated. The maximum tensile stress and limiting oxygen index values of most composites irradiated by EB were more than 15 MPa and 28%. Results revealed that the obtained materials had excellent thermal and mechanical, flame-retardant, and insulation properties, thereby suggesting their promising prospects for wire and cable applications.