Search Results (225)

Graphitic nanomaterials have emerged as foundational components in nanoscience owing to their exceptional electrical, mechanical, and chemical properties, which can be tuned by controlling dimensionality and structural order. From zero-dimensional (0D) quantum dots, carbon nano-onions, and nanodiamonds to one-dimensional (1D) nanoribbons, two-dimensional (2D) nanowalls, and three-dimensional (3D) graphene foams, these architectures underpin advancements in catalysis, energy storage, sensing, and electronic technologies. Among various synthesis routes, chemical vapor deposition (CVD) provides unmatched versatility, enabling atomic-level control over carbon supply, substrate interactions, and plasma activation to produce well defined graphitic structures directly on functional supports. This review presents a comprehensive, dimension-resolved overview of CVD-derived graphitic nanomaterials, examining how process parameters such as precursor chemistry, temperature, hydrogen etching, and template design govern nucleation, crystallinity, and morphological evolution across 0D to 3D hierarchies. Comparative analyses of Raman, XPS, and XRD data are integrated to relate structural features with growth mechanisms and functional performance. By connecting mechanistic principles across dimensional scales, this review establishes a unified framework for understanding and optimizing CVD synthesis of graphitic nanostructures. It concludes by outlining a path forward for improving how CVD-grown carbon nanomaterials are made, monitored, and integrated into real devices so these can move from lab-scale experiments to practical, scalable technologies. Full article

Nanoimprint lithography (NIL) master fidelity is governed by coupled variations beginning with resist spin-coating, proceeding through electron beam exposure, and culminating in anisotropic etch transfer. We present an integrated, physics-based simulation chain. First, it includes a spin-coating thickness model that combines Emslie–Meyerhofer scaling with a Bornside edge correction. The simulated wafer-scale map at 4000 rpm exhibits the canonical center-rise and edge-bead profile with a 0.190–0.206 μm thickness range, while the locally selected 600 nm × 600 nm tile shows <0.1 nm variation, confirming an effectively uniform region for downstream analysis. Second, it couples an e-beam lithography (EBL) module in which column electrostatics and trajectory-derived spot size feed a hybrid Gaussian–Lorentzian proximity kernel; under typical operating conditions (${\sigma }_{traj}$ ≈ 2–5 nm), the model yields low CD bias (ΔCD = 2.38/2.73 nm), controlled LER (2.18/4.90 nm), and stable NMSE (1.02/1.05) for isolated versus dense patterns. Finally, the exposure result is passed to a level set reactive ion etching (RIE) model with angular anisotropy and aspect ratio-dependent etching (ARDE), which reproduces density-dependent CD shrinkage trends (4.42% versus 7.03%) consistent with transport-limited profiles in narrow features. Collectively, the simulation chain accounts for stage-to-stage propagation—from spin-coating thickness variation and EBL proximity to ARDE-driven etch behavior—while reporting OPC-aligned metrics such as NMSE, ΔCD, and LER. In practice, mask process correction (MPC) is necessary rather than optional: the simulator provides the predictive model, metrology supplies updates, and constrained optimization sets dose, focus, and etch set-points under CD/LER requirements. Full article

The operational stability of organic solar cells critically depends on the excited-state characteristics of electron acceptor materials. Through systematic quantum chemical calculations on four representative acceptors (PCBM, ITIC, Y6, and TBT-26), this study reveals fundamental spectra–stability relationships. Non-fullerene acceptors demonstrate superior light-harvesting with systematically tuned energy levels and significantly lower exciton binding energies (2.05–2.12 eV) compared to PCBM (2.97 eV), facilitating efficient charge separation. Structural dynamics analysis uncovers distinct stability mechanisms: ITIC maintains exceptional structural integrity (anionic RMSD = 0.023, S₁ RMSD = 0.134) with superior bond preservation, ensuring balanced performance–stability. Y6 exhibits substantial structural relaxation in excited states (S₁ RMSD = 0.307, T₁ RMSD = 0.262) despite its low exciton binding energy, indicating significant non-radiative losses. TBT-26 employs selective bond stabilization, preserving acceptor–proximal bonding despite considerable anionic flexibility. These findings establish that optimal molecular design requires both favorable electronic properties and structural preservation in photoactive states, providing crucial guidance for developing efficient and stable organic photovoltaics. Full article

This study investigates the impact of 1 MeV electron beam and 80 keV X-ray irradiation on the decomposition rate and radiation–chemical yield of 1-hexanol in aqueous saline solution to develop a comprehensive approach to determining reliable volatile organic compound markers for food irradiation. A 50 mg/L 1-hexanol solution was irradiated with the doses ranging from 100 to 8000 Gy at various dose rates ranging from 0.2 to 10 Gy/s to assess the impact of irradiation parameters on the decomposition rate and radiation–chemical yield of volatile compounds typically found in food. GC–MS analysis revealed a non-linear decrease in 1-hexanol concentration with increasing dose, accompanied by the formation of aldehydes, ketones, and secondary alcohols. Among these products, hexanal was detected at the lowest applied dose and exhibited dose-dependent behavior that correlated strongly with 1-hexanol degradation. Density functional theory calculations identified the most probable pathways for the formation of hexanol decomposition products, involving direct ionization, radical reactions, and oxidation. A mathematical model proposed in the study describes dose-dependent transformations of 1-hexanol into hexanal, enabling quantitative estimation of the degradation extent of hexanol. The findings suggest that hexanal can serve as a quantitative marker for hexanol degradation, supporting the development of rapid “dose range” determination methods for food irradiation that ensure microbial safety while minimizing undesirable oxidation of proteins, fats, and carbohydrates. Full article

In this study, structural optimization and trap effect analysis of a 4H-SiC–based p–i–n betavoltaic (BV) cell were performed using Silvaco ATLAS TCAD (version 5.30.0.R) simulations combined with an electron-beam (e-beam) irradiation model. First, the optimum device structure was derived by varying the thickness of the intrinsic layer (i-layer), the thickness of the p-layer, and the doping concentration of the i-layer. Under 17 keV e-beam irradiation, the electron–hole pairs generated in the i-layer were effectively separated and transported by the internal electric field, thereby contributing to the short-circuit current density (J_SC), open-circuit voltage (V_OC), and maximum output power density (P_{out_max}). Subsequently, to investigate the effects of traps, donor- and acceptor-like traps were introduced either individually or simultaneously, and their densities were varied to evaluate the changes in device performance. The simulation results revealed that traps degraded the performance through charge capture and recombination, with acceptor-like traps exhibiting the most pronounced impact. In particular, acceptor-like traps in the i-layer significantly reduced V_OC from 2.47 V to 2.07 V and P_{out_max} from 3.08 μW/cm² to 2.28 μW/cm², demonstrating that the i-layer is the most sensitive region to performance degradation. These findings indicate that effective control of trap states within the i-layer is a critical factor for realizing high-efficiency and high-reliability SiC-based betavoltaic cells. Full article

Alanine dosimetry based on Electron Paramagnetic Resonance (EPR) spectroscopy has been a reliable reference and transfer dosimetry method in high-dose applications, valued for its high precision, accuracy and long-term stability. Additional characteristics, such as dose-rate independence up to 10¹⁰ Gy/s under electron beam (e-beam) irradiation, electron energy independence and tissue equivalence, position alanine EPR as a promising candidate to address dosimetric challenges arising in e-beam Flash Radiotherapy (RT), where radiation energy is delivered at Ultra-High Dose-Rates (UHDR) ≥ 40 Gy/s. At such dose-rates, reliable real-time monitoring dosimeters such as ionization chambers in conventional RT, suffer from ion recombination, compromising accuracy in dose determination. Several studies are currently focused on developing real-time beam monitoring systems dedicated specifically for e-beam Flash RT. This creates a need for standardized reference dosimetry methods to validate beam parameters determined by these systems under investigation. This review provides an overview of the potential and limitations of the alanine EPR dosimetry method for control, validation and verification of e-beam Flash RT beam parameters at doses less than 10 Gy, where the method has shown low sensitivity and increased uncertainty. It further discusses strategies to optimize alanine EPR measurements to enhance sensitivity and accuracy at these dose levels. Improved measurement procedures will ensure reliable and accurate e-beam Flash RT accelerator commissioning, performance checks, patient safety and treatment efficacy across all therapeutic dose ranges. Full article

Polycaprolactone (PCL) is one of the most widely used polymers in tissue engineering owing to its excellent biocompatibility, biodegradability, and processability. Nevertheless, most previous studies have primarily employed research-grade PCL, thereby limiting its clinical translation. In this study, four types of medical-grade PCL (RESOMER^® C203, C209, C212, and C217) were systematically evaluated for their applicability in three-dimensional (3D) printing, with respect to printability, mechanical characteristics, chemical stability, and biodegradation behavior. Among these, C209 and C212 exhibited superior printability and mechanical strength. FT-IR analysis showed that the chemical structure of PCL remained unchanged after both 3D printing and E-beam sterilization, while compressive testing demonstrated no significant differences in mechanical characteristics. In vitro degradation assessment revealed a time-dependent decrease in molecular weight. For kinetic analysis, both C209 and C212 were fitted using pseudo-first-order and pseudo-second-order models, which yielded comparable coefficients of determination (R²), suggesting that degradation may be governed by multiple factors rather than a single kinetic pathway. Taken together, these findings indicate that medical-grade PCL, particularly C209 and C212, is highly suitable for 3D printing. Furthermore, this study provides fundamental insights that may facilitate the clinical translation of PCL-based scaffolds for tissue engineering and biomedical implantation. Full article

Wearable and skin-mounted electronics demand encapsulation designs that simultaneously provide strong barrier performance, mechanical reliability, and transferability under ultrathin conditions. In this study, a residual stress-balanced transferable encapsulation platform was developed by integrating a urethane-based copolymer superstrate [p(IEM-co-HEMA)] with inorganic thin films. The polymer, deposited via initiated chemical vapor deposition (iCVD), offered over 90% optical transmittance, low RMS roughness (1–3 nm), and excellent solvent resistance, providing a stable base for inorganic barrier integration. An ALD Al₂O₃/ZnO nano-stratified barrier initially delivered effective moisture blocking, but tensile stress accumulation imposed a critical thickness of 30 nm, where the WVTR plateaued at ~2.5 × 10⁻⁴ g/m²/day. To overcome this limitation, a 40 nm e-beam SiO₂ capping layer was added, introducing compressive stress via atomic peening and stabilizing Al₂O₃ interfaces through Si–O–Al bonding. This stress-balanced design doubled the critical thickness to 60 nm and reduced the WVTR to 3.75 × 10⁻⁵ g/m²/day, representing an order-of-magnitude improvement. OLEDs fabricated on this ultrathin platform preserved J–V–L characteristics and efficiency (~4.5–5.0 cd/A) after water-assisted transfer and on-skin deformation, while maintaining LT80 lifetimes of 140–190 h at 400 cd/m² and stable emission for over 20 days in ambient storage. These results demonstrate that the stress-balanced encapsulation platform provides a practical route to meet the durability and reliability requirements of next-generation wearable optoelectronic devices. Full article

Gellan gum (Gellan), a versatile polysaccharide applied in gel formation and prebiotic formulations, is often processed to tailor its molecular properties. Previous studies employed gamma irradiation and chemical hydrolysis, though without addressing systematic scaling behavior. This study investigates the structural and conformational modifications of Gellan in dilute aqueous salt solutions using a safer and eco-friendly approach: atmospheric low-dose electron beam (e-beam) degradation coupled with viscosity analysis. Native and E-beam-treated Gellan samples (0.05 g/cm³ in 0.1 M KCl) were examined by relative viscosity at varying temperatures, with intrinsic viscosity and molar mass determined via Solomon–Ciuta and Mark–Houwink relations. Molar mass degradation followed first-order kinetics, yielding rate constants and degradation lifetimes. Structural parameters, including radius of gyration and second virial coefficient, produced scaling coefficients of 0.62 and 0.15, consistent with perturbed coil conformations in a good solvent. The shape factor confirmed preservation of an ideal random coil structure despite irradiation. Conformational flexibility was further analyzed using theoretical models. Transition state theory (TST) revealed that e-beam radiation lowered molar mass and activation energy but raised activation entropy, implying reduced flexibility alongside enhanced solvent interactions. The freely rotating chain (FRC) model estimated end-to-end distance (R_θ) and characteristic ratio (C_∞), while the worm-like chain (WLC) model quantified persistence length (l_p). Results indicated decreased R_θ, increased l_p, and largely unchanged C_∞, suggesting diminished chain flexibility without significant deviation from ideal coil behavior. Overall, this work provides new insights into Gellan’s scaling laws and flexibility under aerobic low-dose E-beam irradiation, with relevance for bioactive polysaccharide applications. Full article

Miscanthus × giganteus particles possess excellent advantages in biodegradability and sustainability. However, their susceptibility to ultraviolet (UV) degradation limits wider outdoor applications. In the present work, electron beam (e-beam) radiation-induced grafting was used for the first time to attempt covalent grafting of UV absorbers onto miscanthus particles to address a major challenge in natural fiber stabilization. Two UV absorbers, 2-hydroxy-4-(methacryloyloxy) benzophenone (HMB) and 2-(4-benzoyl-3-hydroxyphenoxy) ethyl acrylate (BHEA), were explored using both pre-irradiation and simultaneous approaches. Pre-irradiation grafting did not achieve useful covalent fixation of HMB or BHEA, due in part to the premature decay of radicals at elevated temperatures and with solvent use, and the lignin-based quenching of radicals. Solvent-free mutual irradiation grafting failed due to immobility of the UV absorbers, while grafting of HMB in solvent failed due to radical-scavenging behavior. Grafting of BHEA was successfully achieved under solvent-based simultaneous irradiation, reaching up to 38 wt % DG in a butanone/2.5% H₂SO₄ system. This condition led to the improved UV stability of miscanthus particles, in which color change was reduced significantly after 1000 h of accelerated weathering; this was mainly linked to a beneficial pre-darkening effect which was induced by the presence of the acid. This work proposes a route of grafting strategy that aims to improve the photostability of miscanthus particles, paving the way for durable bio-based materials in outdoor composite applications. Full article

Background: Bacterial Chondronecrosis with Osteomyelitis (BCO) is a significant issue affecting the welfare and economy of the broiler industry, causing substantial revenue losses annually. This disease is frequently associated with Staphylococcus spp. and Enterococcus spp. infections and necrosis of leg and vertebral bones. The typical annual lameness incidence of approximately 3–5% may increase to 30% during outbreaks. Neither the etiology or pathogenesis of the disease has been comprehended, nor have effective preventative measures been identified. Electron beam (eBeam) technology is renowned for producing efficient whole-cell vaccines by preventing bacterial multiplication through irreversible DNA shredding while preserving the integrity of membrane proteins (immunogenic epitopes). This study aims to reduce BCO-induced lameness in broiler chickens via in ovo immunization using eBeam-inactivated multi-strain Staphylococcus. Methods: A total 1080 birds were assigned to four vaccination groups: eBeam-inactivated, formalin-inactivated, combination of eBeam- and formalin-inactivated, and sham (vehicle). The birds were directly exposed to aerosolized, natural BCO challenge until 56 days of age. Results: Birds vaccinated with the eBeam-inactivated Staphylococcus vaccine showed a significant reduction (>50%) in daily cumulative lameness compared to other groups and a decrease in Staphylococcus colonization was observed in the leg joints of treated birds. Conclusions: the eBeam-inactivated Staphylococcus vaccine successfully prevented BCO lameness in broiler chickens. Full article

This review summarizes the recent advances in the application of nanomaterial coatings in optical fiber sensors, with a particular focus on deposition techniques and the research progress over the past five years in humidity sensing, gas detection, and biosensing. Benefiting from the high specific surface area, abundant surface active sites, and quantum confinement effects of nanomaterials, advanced thin-film fabrication techniques—including spin coating, dip coating, self-assembly, physical/chemical vapor deposition, atomic layer deposition (ALD), electrochemical deposition (ECD), electron beam evaporation (E-beam evaporation), pulsed laser deposition (PLD) and electrospinning, and other techniques—have been widely employed in the construction of functional layers for optical fiber sensors, significantly enhancing their sensitivity, response speed, and environmental stability. Studies have demonstrated that nanocoatings can achieve high-sensitivity detection of targets such as humidity, volatile organic compounds (VOCs), and biomarkers by enhancing evanescent field coupling and enabling optical effects such as surface plasmon resonance (SPR), localized surface plasmon resonance (LSPR), and lossy mode resonance (LMR). This paper first analyzes the principles and optimization strategies of nanocoating fabrication techniques, then explores the mechanisms by which nanomaterials enhance sensor performance across various application domains, and finally presents future research directions in material performance optimization, cost control, and the development of novel nanocomposites. These insights provide a theoretical foundation for the functional design and practical implementation of nanomaterial-based optical fiber sensors. Full article

Prolonged drought and soil degradation severely affect soil fertility and limit crop productivity. Superabsorbent hydrogels offer an effective solution for improving water retention in soil and supporting plant growth. In this work, we examined the performance of superabsorbent hydrogels based on sodium alginate, acrylic acid (AA), and poly (ethylene oxide) (PEO) cross-linked with 12.5 kGy using e-beam irradiation. The hydrogels were assessed in various aqueous environments by examining network characteristics, swelling capacity, and swelling kinetics to evaluate the impact of water’s electrical conductivity (which ranges from 0.05 to 321 μS/cm). Morphological and chemical structure changes were evaluated using SEM and FTIR techniques. The results demonstrated that water conductivity significantly affected the physicochemical properties of the hydrogels. Swelling behavior showed notable sensitivity to electrical conductivity variations, with swelling degrees reaching 28,400% at 5 μS/cm and 14,000% at 321 μS/cm, following first-order and second-order kinetics. FTIR analysis confirmed that structural modifications correlated with water conductivity, particularly affecting the O–H, C–H, and COOH groups sensitive to the ionic environment. SEM characterization revealed a porous morphology with an interconnected microporous network that facilitates efficient water diffusion. These hydrogels show exceptional swelling capacity and are promising candidates for sustainable agriculture applications. Full article

Nanoscale zinc sulfide (ZnS) powders have attracted considerable interest due to their unique properties and diverse applications in various fields, including wastewater treatment, optics, electronics, photocatalysis, and solar systems. In this study, nano-powder ZnS was chemically synthetized starting from Zn powder, diluted HCl, and laboratory-prepared Na2S. The obtained ZnS was studied using an SEM coupled with EDS, XRD analysis, UV–Visible spectroscopy, and FTIR techniques. The XRD results showed that the synthesized nanoscale ZnS powder was approximately 2.26 nm. Meanwhile, the EDS and XRD patterns confirmed the high purity of the obtained ZnS powder. In addition, the ZnS powder was compacted and sintered in an argon atmosphere at 400 °C for 8 h to prepare the required pellets for thin-film deposition via E-beam evaporation. The microscopic structure of the sintered pellets was investigated using the SEM/EDS. Furthermore, the optical properties of the deposited thin films were studied using UV–Visible spectroscopy in the wavelength range of 190–1100 nm and the FTIR technique. The bandgap energies of the deposited thin films with thicknesses of 111 nm and 40 nm were determined to be around 4.72 eV and 5.82 eV, respectively. This article offers a facile production route of high-purity ZnS powder, which can be compacted and sintered as a suitable source for thin-film deposition. Full article