Electron Beam Irradiation Research Articles

Adsorption mechanism of hexavalent chromium on electron beam-irradiated aged microplastics: Novel aging processes and environmental factors

Microplastics are widely present in the natural environment and exhibit a strong affinity for heavy metals in water, resulting in the formation of microplastics composite heavy metal pollutants. This study investigated the adsorption of heavy metals by electron beam-aged microplastics. For the first time, electron beam irradiation was employed to degrade polypropylene, demonstrating its ability to rapidly age microplastics and generate a substantial number of oxygen-containing functional groups on aged microplastics surface. Adsorption experiments revealed that the maximum adsorption equilibrium capacity of hexavalent chromium by aged microplastics reached 9.3 mg g−1. The adsorption process followed second-order kinetic model and Freundlich model, indicating that the main processes of heavy metal adsorption by aged microplastics are chemical adsorption and multilayer adsorption. The adsorption of heavy metals on aged microplastics primarily relies on the electrostatic and chelation effects of oxygen-containing functional groups. The study results demonstrate that environmental factors, such as pH, salinity, coexisting metal ions, humic acid, and water matrix, exert inhibitory effects on the adsorption of heavy metals by microplastics. Theoretical calculations confirm that the aging process of microplastics primarily relies on hydroxyl radicals breaking carbon chains and forming oxygen-containing functional groups on the surface. The results indicate that electron beam irradiation can simultaneously oxidize and degrade microplastics while reducing hexavalent chromium levels by approximately 90%, proposing a novel method for treating microplastics composite pollutants. Gas chromatography-mass spectrometry analysis reveals that electron beam irradiation can oxidatively degrade microplastics into esters, alcohols, and other small molecules. This study proposes an innovative and efficient approach to treat both microplastics composite heavy metal pollutants while elucidating the impact of environmental factors on the adsorption of heavy metals by electron beam-aged microplastics. The aim is to provide a theoretical basis and guidance for controlling microplastics composite pollution.

Hybrid pasteurization strategy for energy conservation and quality preservation in cloudy apple juice processing

The study investigates the combination of microfiltration (MF) with traditional thermal pasteurization (TP), high-pressure processing (HPP), and electron beam irradiation (EBI) in the production of cloudy apple juice. Using 0.22 μm MF membranes instead of 0.45 or 0.1 μm, the highest flux was achieved, the permeate and retentate exhibited minimal deviation from raw apple juice (RAJ) in terms of physicochemical indicators. MF divided RAJ into a cloudy retentate containing microorganisms and a clarified permeate in a 1:4 vol ratio. The retentate was then pasteurized by HPP, TP, and EBI, after which it was mixed with the permeate to create cloudy apple juice. This innovative process reduced processed juice volume by 80% compared to single pasteurization method, decreased the loss of volatile compounds by 20.05%–33.52%, and cut energy consumption by 72.29%–75.35%. Overall, the hybrid pasteurization strategy approach shows great promise pasteurization technique for producing high-quality cloudy apple juice.

Isolated single-photon emitters with low Huang–Rhys factor in hexagonal boron nitride at room temperature

The development of stable room-temperature bright single-photon emitters using atomic defects in hexagonal boron nitride flakes (h-BN) provides significant promise for quantum technologies. However, an outstanding challenge in h-BN is the creation and detection of isolated, stable single-photon emitters with high emission rates and with very low Huang–Rhys (HR) factor. Here, we discuss the quantum photonic properties of a single, isolated, stable quantum emitter that emits single photons with a high emission rate and a low HR value of 0.6 ± 0.2 at room temperature. A scanning confocal image confirms the presence of a deserted, single-quantum emitter with a prominent zero-phonon line at ∼578 nm with a well-separated phonon sideband at 626 nm. The second-order intensity-intensity correlation measurement shows an anti-bunching dip of ∼0.25 with an emission lifetime of 2.46 ± 0.1 ns, reinforcing distinct features of the single-photon emitter. The importance of low-energy electron beam irradiation and subsequent annealing is emphasized to achieve stable, reproducible single-photon emitters.

Total Third-Degree Variation for Noise Reduction in Atomic-Resolution STEM Images.

Scanning Transmission Electron Microscopy (STEM) enables direct determination of atomic arrangements in materials and devices. However, materials such as battery components are weak for electron beam irradiation and low electron doses are required to prevent beam-induced damages. Noise removal is thus essential for precise structural analysis of electron beam sensitive materials at atomic resolution. Total square variation (TSV) regularization is an algorithm that exhibits high noise removal performance. However, the use of the TSV regularization term leads to significant image blurring and intensity reduction. To address these problems, we here propose a new approach adopting L2 norm regularization based on higher-order total variation. An atomic-resolution STEM image can be approximated as a set of smooth curves represented by quadratic functions. Since the third-degree derivative of any quadratic function is 0, total third-degree variation (TTDV) is suitable for a regularization term. The application of TTDV for denoising the atomic-resolution STEM image of CaF2 observed along the [001] zone axis is shown, where we can clearly see the Ca and F atomic columns without compromising image quality.

Effects of electron beam irradiation on microbial load, physicochemical properties, sensory quality, stability of active components, and antioxidant activity of Platycodon grandiflorum (Jacq.) A. DC.

Platycodon grandiflorum (Jacq.) A. DC. (PG) is an edible and medicinal plant. This study aimed to investigate the potential of electron beam (EB) irradiation for preserving PG. EB Irradiation at doses of 2-8 kGy were applied to PG, and the effects on microbial content, sensory qualities, chemical qualities, and EB penetration were examined. Results showed that irradiation with 6 kGy effectively maintained PG's microbiological quality of PG when packing thickness was ≤ 6.3cm during a 360-day storage period. The physicochemical properties, color, active ingredient contents, and antioxidant capacities of PG remained unaffected. However, total flavonoid and Platycodin-D content exhibited a non-dose-dependent alteration. The use of electronic nose analysis successfully differentiated the odor of EB irradiated PG samples from non-irradiated ones. Fingerprint analysis also indicated no significant impact of EB irradiation on PG quality. These findings suggest that EB treatment could be a valuable approach for extending the shelf life of PG.

Sulfur as an effective sensitizer for natural rubber vulcanized via electron beam irradiation

AbstractA sensitizer or crosslinking promoter must be utilized to improve electron beam irradiation (EBI) vulcanization and achieve optimal results. This work investigated the effect of sensitizers, that is, sulfur and trimethylolpropane trimethacrylate (TMPT), on the properties of EBI‐vulcanized natural rubber (NR). The experiments focused on analyzing the effect of different amounts of sensitizers, that is, 2 and 3 phr, on the swelling, crosslink density, entanglement, and mechanical properties of NR latex. A sample without sensitizers was taken as a reference. Results revealed that the crosslink density of the samples with sensitizers had improved compared with that of the sample without a sensitizer. The sample with sulfur exhibited higher crosslink density than the NR with TMPT. The sulfur‐containing NR exhibited superior mechanical properties, i.e., modulus, tensile strength, and tear strength, as its crosslink density increased. In addition, increasing the sulfur content reduced the crosslink density of the NR latex, resulting in inferior mechanical properties. Furthermore, the different forms, that is, latex and film, of NR were compared. The latex form revealed higher crosslink density than the film form, thus presenting high mechanical properties because it contained water, which could induce the formation of free radical species and enhance crosslinking.

Impact of high-energy electron beam irradiation on piezoelectric properties of lead zirconate titanate

We measured the resonant and anti-resonant frequencies of lead zirconate titanate (PZT) elements at various temperatures and investigated the change in the electromechanical coupling coefficient to clarify the temperature dependence of the elements. Based on these results, we performed a 20 MeV electron beam irradiation experiment on the PZT elements. We found that the electromechanical coupling coefficient decreased as the cumulative energy absorption due to beam irradiation increased, even when the effect of the temperature rise due to beam irradiation was negligible.

The refined microstructure and enhanced properties of the Al-Mo laser-alloyed layer after high-current pulsed electron beam irradiation

The aim of this study is to investigate the microstructure and properties of the AlMo laser-alloyed layer induced by high-current pulsed electron beam (HCPEB) irradiation. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy were utilized to investigate the microstructures of the modified layer. The microhardness and friction properties were also measured. The microstructural observation shows that HCPEB irradiation led to the formation of a modified layer approximately a dozen microns thick, which was the absence of the pores. It was found that the flower- and strip-like AlMo particles were dissolved to form nano-size particles consisting of Al5Mo (h2), Al12Mo, and Al17Mo4 phase after HCPEB irradiation. Additionally, the slip bands and high-density dislocations were formed in the modified layer. The refined microstructure significantly enhanced the microhardness of the laser-alloyed layer. A quantitative evaluation was conducted to investigate the individual contributions of four strengthening mechanisms to the strength of the modified layer, which indicated that dislocation and grain boundary strengthening were dominant. The results of sliding wear tests show that the modified layer exhibited superior properties compared to the laser alloying layer, which was attributed to the formation of crystal defects, solid solutions, and nanoparticles.

Electron Beam Restructuring of Quantum Emitters in Hexagonal Boron Nitride

AbstractHexagonal boron nitride (hBN) holds promise as a solid state, van der Waals host of single photon emitters for on‐chip quantum photonics. The B‐center defect emitting at 436 nm is particularly compelling as it can be generated by electron beam irradiation. However, the emitter generation mechanism is unknown, the robustness of the method is variable, and it has only been applied successfully to thick flakes of hBN (≫ 10 nm). Here, it is used in situ time‐resolved cathodoluminescence (CL) spectroscopy to investigate the kinetics of B‐center generation. It is shown that the generation of B‐centers is accompanied by quenching of a carbon‐related emission at ≈305 nm and that both processes are rate‐limited by electromigration of defects in the hBN lattice. It identifies problems that limit the efficacy and reproducibility of the emitter generation method and solve them using a combination of optimized electron beam parameters and hBN pre‐and postprocessing treatments. It is achieved B‐center quantum emitters in hBN flakes as thin as 8 nm, elucidate the mechanisms responsible for electron beam restructuring of quantum emitters in hBN, and gain insights toward the identification of the atomic structure of the B‐center quantum emitter.

Utilization of agro waste activated carbons as carbon black replacement in electron beam irradiated styrene butadiene rubber composites

Purpose This study aims to prepare activated carbon (AC) and activated biochar (BC) from sugarcane bagasse (SCB) can be used as carbon black (CB) replacement for styrene butadiene rubber (SBR) composites cured by electron beam (EB) radiation. Design/methodology/approach This study is carried out to investigate the effect of partial replacement of CB (as traditional filler) by AC or BC prepared from low-cost agricultural wastes (SCB) to improve the properties of SBR rubber cured by EB radiation (doses from 25 to 150 kGy). Findings The results indicated that the addition of AC or BC leads to improve the physical and mechanical properties of SBR with increasing irradiation dose [especially at concentration of 10 parts per hundred part of rubber (phr) from BC]. Also in this study, this paper examines how exposure of SBR rubber composites to ultraviolet (UV) radiation changes the mechanical properties for these composites, to do that, the specimens were examined before and after they were exposed to UV radiation for 300 h. The results showed that, the irradiated SBR composites, UV exposure, exhibit better retention in mechanical properties as compared with unirradiated ones, and the samples loaded with CB hybrid with ACs had an increased value of tensile strength (TS) retention as compared with blank sample. Originality/value The importance of this study is that, the production of AC from SCB offers a huge opportunity to overcome the problem of the disposal of SCB.

Sequential effects of autoclaved heat treatment and electron beam irradiation on acorn starch: Multiscale structural differences and related mechanisms

In this study, the differences in the modification effects and related mechanisms of different times (20 and 40 min) of autoclaved heat (AH) treatment and different doses (2 and 4 kGy) of electron beam irradiation (EBI) in different sequences of effects on acorn starch were investigated. The results showed that both AH and EBI reduced the amylose content (22.70 to 19.59%) and enthalpy (10.28 to 1.84%) of starch but increased the resistant starch content (53.69 to 64.11%). AH treatment made the crystalline regions of the residual starch granules denser, which was resistant to the action of amylase enzymes. EBI degraded the long chain of starch, which increased the solubility. Notably, EBI pretreatment improves the reactive sites by inducing depolymerization and disorder in starch internal structure, thus increasing the modification extent of AH-modified starch, forming starch with lower viscosity, better hydration, and digestibility resistance, therefore being used as an ingredient for functional foods.

Effects of gamma, electron beam, and X-ray irradiation on the plastic components of a universal bone cement mixer medical device

Due to market and regulatory pressures, many healthcare manufacturers are considering alternatives to cobalt-60 gamma radiation, including accelerator-based electron beam (E-beam) and X-ray radiation for product sterilization. In this work, the effects of irradiation on a representative medical product, comprised of eight distinct polymer materials, were directly compared for three radiation technologies – cobalt-60 gamma, E-beam, and X-ray – at four dose levels (15, 25, 50, and 70 kGy). The objective was to determine how radiation effects (deleterious or beneficial) are influenced by source and dose level, with the specific goal of determining whether E-beam radiation and/or X-ray radiation could be viable alternatives to gamma radiation for device sterilization. The specific product considered is a single-use medical device for orthopedic surgery, the Stryker Instruments MixeVac III bone cement mixer, which is currently sterilized using gamma radiation from cobalt-60 sources. Following ASTM International standards and input from the manufacturer, we characterized the effects of the three radiation sources on product functionality as well as on the mechanical and optical properties of the constituent polymers. Results indicate that although measurable differences in properties between the standard gamma irradiated materials and the alternative E-beam and X-ray irradiated materials were observed, those differences were small. Statistically significant differences were noted in the case of yellowness index for polyvinyl chloride, high-density polyethylene, and polycarbonate, and in the case of tensile elongation at break for high impact polystyrene and polyvinyl chloride. In general, the results of this study support the viability of E-beam and X-ray radiation as alternative options to cobalt-60 gamma radiation for sterilization of Stryker single-use universal bone cement mixer medical devices.

Bridging the future: unveiling the latest innovations in ethylene vinyl acetate blends and composites through electron beam irradiation—a comprehensive review

Bridging the future: unveiling the latest innovations in ethylene vinyl acetate blends and composites through electron beam irradiation—a comprehensive review

Application of electron beam irradiation and mild thermal treatment of Bacillus cereus spores in Chinese braised beef cuisine

ABSTRACT The individual and combined effects of electron beam (EB) irradiation and thermal treatments were investigated on Chinese braised beef samples inoculated with Bacillus cereus spores. Log reductions of 1.19, 2.10, and 3.62 log CFU/g were recorded for B. cereus spores after 6, 9, and 12 kGy lone EB doses, respectively. An 85°C thermal treatment at 20 min (H) reduced the spores population by 1.03 log CFU/g. The combination of the thermal and EB irradiation treatments (HEB) of HEB-6 and HEB-9 achieved 1.69 and 2.89 log CFU/g reductions, respectively. The B. cereus spores population was depleted to below the detection limit following HEB-12 treatment. No significant pH change was observed in the treatments except for HEB-12. The hurdle treatment of HEB-12 caused marked changes in color, aroma, and overall acceptability. Although HEB irradiation improved microbial safety, careful selection of approved EB doses can effectively enhance food safety and maintain reasonable quality standards.

Identification and time evolution of thionyl chloride (SOCl2) radiolysis products

Abstract Innovative solutions are needed to reduce the amount of high-level waste generated by used nuclear fuel recycling strategies to support the widespread adoption of sustainable nuclear fission energy technologies. To this end, a new sulfur chloride-based process has been developed to recycle zirconium alloy-based materials, which make up a significant fraction of high-level radioactive waste. To support the continued development of this process, we present new data on the potential reaction pathways over time of the products arising from the gamma and electron beam radiolysis of neat thionyl chloride (SOCl2). Interrogation of the gamma irradiated liquid by Raman spectroscopy provided more conclusive identification of the SOCl2 degradation products, specifically sulfur dichloride (SCl2), molecular chlorine (Cl2), sulfur dioxide (SO2), and sulfuryl chloride (SO2Cl2). In comparison, the high dose rate (∼107 Gy s−1) electron beam irradiations formed significantly more degradation products. For both cobalt-60 gamma and electron beam irradiations, the observed degradation products were found to evolve as a function of time post-irradiation via the same reaction pathways, with indication of a solvent regeneration mechanism. These findings are fortuitous for process development, as such a mechanism would be beneficial for process longevity and cost effectiveness.

Reversible phase transformations between Pb nanocrystals and a viscous liquid-like phase.

Phase transformations have been a prominent topic of study for both fundamental and applied science. Solid-liquid reaction-induced phase transformations can be hard to characterize, and the transformation mechanisms are often not fully understood. Here, we report reversible phase transformations between a metal (Pb) nanocrystal and a viscous liquid-like phase unveiled by in situ liquid cell transmission electron microscopy. The reversible phase transformations are obtained by modulating the electron current density (between 1000 and 3000 electrons Å-2 s-1). The metal-organic viscous liquid-like phase exhibits short-range ordering with a preferred Pb-Pb distance of 0.5 nm. Assisted by density functional theory and molecular dynamics calculations, we show that the viscous liquid-like phase results from the reactions of Pb with the CH3O fragments from the triethylene glycol solution under electron beam irradiation. Such reversible phase transformations may find broad implementations.

Spectral features of pristine and irradiated white emitting InGaN LEDs with quantum wells

The emission spectra of InGaN/GaN white light emitting diodes (WLEDs) were measured. The main emission components were a LED blue line with λmax = 443 nm and a wide double band in the range of 500…650 nm of the secondary emission of AIT-YAG phosphor (Ce). The observed non-monotonic temperature dependence of the emission was attributed to the electric-field screening effect by mobile carriers as well as to thermal quenching due to the increased density of the phonon gas. The power conversion factor of phosphor emission increased in the temperature range of 200…290 K. The total energy losses for the Stokes shift were 82% and 77% for the first (blue) and the second band, respectively. The decrement of emission at high injection currents (over 20 mA) was attributed to ballistic transfer of carriers above the quantum wells and subsequent non-radiative recombination in the barrier layers. The existence of long-term relaxation processes in the white LEDs was assumed to be due to the accumulation of In atoms. Electron beam irradiation caused WLED efficiency degradation due to the introduction of deep traps in the quantum well region. The radiation resistance of the AIT-YAG phosphor was ~1.6 times higher than that of the InGaN part.

Irradiation Effect in Thermoelectric Polymer Polyaniline Induced by High-Energy Electron Beam

A comprehensive investigation was conducted on the relationships between molecular structure, morphology and thermoelectric properties of HCl-doped polyaniline (PANi) nanorods subjected to 10[Formula: see text]MeV electron beam irradiation. Morphological and structural characterization revealed that the crystallinity of irradiated PANi nanorods remained almost unchanged, and minimal oxygen content was detected. This resulted in minimal alterations to the thermo-stability. In addition, the thermoelectric properties of PANi were enhanced. A maximum conductivity of 22.85[Formula: see text]S/cm was obtained at 50[Formula: see text]kGy, which was 1.46 times that of pristine PANi. Interestingly, the Seebeck coefficient reached a maximum of −3.56[Formula: see text][Formula: see text]V/K at 100[Formula: see text]kGy, indicating [Formula: see text]-type organic semiconductor properties. However, a peak power factor of 0.024[Formula: see text][Formula: see text]W[Formula: see text]m[Formula: see text] K[Formula: see text] was achieved with 60[Formula: see text]kGy irradiation, which was slightly enhanced compared to 0.018[Formula: see text][Formula: see text]W[Formula: see text]m[Formula: see text][Formula: see text]K[Formula: see text] for pristine PANi. These results demonstrate that PANi exhibits good irradiation resistance after irradiated with a dose of 100[Formula: see text]kGy. Thus, PANi could be used in high-[Formula: see text] ray (electron) environments, such as radioisotope thermoelectric generators (RTGs).

First-principles study of Stone–Wales defects in monolayer and Bernal-stacked hexagonal boron nitride

Recently, Stone–Wales (SW) defects gradually attracted people’s research interest because of their unique properties. The theoretical research indicated that the SW defect in hexagonal boron nitride (h-BN) can lead to new defect levels in bandgap, making h-BN apply in ultraviolet emitters. However, the SW defect is always observed in graphene and rarely observed in h-BN in the experiments. Here, we confirmed the SW defects are not easily formed in h-BN under thermodynamic conditions by first-principles calculations. Specifically, the monolayer h-BN with SW defect (h-BN-SW) has the weak bond strength, dynamic stability and high-temperature thermal stability, facilitating the healing of SW defects under high-temperature conditions and the role of hydrogen. Additionally, we found the SW defect in AB stacked h-BN (AB-h-BN) have good mechanical stability, dynamic stability and thermodynamic stability than h-BN-SW, especially for AB-h-BN-2SW (2SW defects formed in upper and lower layer of AB-h-BN, respectively), which can meet the requirements for its application in electronic devices. Even under thermodynamic conditions, the formation of SW defects is extremely challenging. Electron beam irradiation technology provides a window for the generation of SW defects in h-BN. This offers opportunities for the introduction and control of SW defects, while also creating potential for their application in electronic devices. Moreover, we found that the absorption peak broadens, and a new absorption peak appears with the generation of SW defects, which is mainly induced by the decrease of bandgap and the generation of defect levels. Our research can provide theoretical guidance at atomic scale for designing and applying h-BN with SW defect in the experiments.

Electron beam irradiation-induced atomically thin domes of two-dimensional materials: Graphene and MoS[formula omitted]

The local strain-induced indirect-to-direct band gap transition in bulk transition metal dichalcogenides (TMDCs) holds great potential for optoelectronic applications. The formation of domes on the topmost layer of a multilayered flake through hydrogen ion H+ irradiation is an effective technique for tuning the band gap locally via molecular hydrogen (H2) confinement. In this work, we present an alternative robust, simpler, and faster technique for concurrently forming and visualizing dome-like structures of two-dimensional (2D) materials through low-energy electron beam irradiation. We investigated the growth mechanism and dynamics of the domes under exposure to electron beams at different energy levels. The simultaneous production and imaging of atomically thin domes of 2D materials has several practical and fundamental applications, such as mass storage and transport, single photon emission, nano/micro-electromechanical sensors, strain engineering, etc.