Γ-irradiation Dose Research Articles

Fabrication of Al/n-GaN/p-Si/Al diodes by thermal evaporation and evaluation of effect of gamma irradiation on device properties

This study investigates the impact of γ-irradiation on the material and device properties of Al/n-GaN/p-Si/Al heterojunction diodes. GaN thin films were deposited on glass and p-Si substrates using thermal evaporation, followed by annealing at 450 °C. The diodes were subjected to γ-irradiation doses of 0, 3, and 6 kGy. X-ray diffraction (XRD) measurements revealed significant structural changes, including phase transitions influenced by radiation. Electrical characteristics were assessed through current–voltage (I-V) measurements within the ± 2 V range. Notably, the ideality factor for the annealed diodes improved from 6.60 to 4.62 and 3.85 with increased γ-irradiation. The barrier height was determined to be 0.85 eV, and it did not exhibit a significant change upon γ-irradiation dose. The results provided valuable insights into the response of heterojunction diodes to radiation exposure, aiding in the understanding and potential improvement of the radiation resistance of GaN-based electronic devices.

Enhancement of crystallinity and the optical properties in gamma irradiated and thermally annealed cobalt doped MgTiO3 thin films

We report the crystal structure, surface morphology and optical properties of gamma (γ) irradiated, and thermally annealed cobalt (5 %) doped magnesium titanate thin films. Mg0.95Co0.05TiO3 (MCT) thin films were fabricated on quartz substrates by Radio Frequency magnetron sputtering while substrate temperature was maintained at 300 °C. Firstly, the as-prepared MCT thin films were irradiated by 1.33 MeV 60Co γ – rays with varying doses in the range of 0 – 125 kGy with the intervals of 25 kGy and post-annealing process at 700 °C. The X-ray diffraction pattern of irradiated thin films is amorphous, whereas annealed films are crystalline, which are refined with the Rietveld refinement method by considering the R3¯space group. Dominated crystallite size (39 nm) with low strain is identified for the samples exposed at 75 kGy. In addition to the γ-irradiation of 75 kGy, the optical characteristics revealed that an enhanced bandgap (∼ 4.27 eV) and refractive index (2.26) had been observed for an annealed sample as compared with the bandgap (∼ 3.68 eV) and refractive index (2.10) of as-deposited sample. The influence of γ-irradiation dose and annealing on MCT thin films' structural and optical properties has been discussed. This study demonstrates that the γ–ray irradiated MCT films are potential candidates for anti-reflection coating applications.

Effects of Gamma Irradiation on Polyethylene Terephthalate and Detection of Microplastic Particles Down to 1 μm.

In response to increasing concern about the impact of plastic degradation on the environment, this study investigates the degradation of virgin and recycled polyethylene terephthalate (PET) under γ-irradiation in aqueous solutions, with particular focus on the resulting formation of microplastic particles (MP). By exposing both virgin and recycled PET samples to different doses of γ-irradiation (10, 50, and 100 kGy), a comprehensive analysis using UV-vis spectroscopy, dynamic light scattering (DLS) and micro-Raman spectroscopy is presented. The results, highlighted by micro-Raman spectroscopy, show that γ-irradiation produces micrometer-sized plastic particles, with the recycled PET having a significantly higher MP content than its original counterpart. Careful examination reveals the presence of a stabilizer in samples of recycled PET juice bottles. This study not only contributes to our understanding of the effects of γ-irradiation on PET but also highlights the need for further research into the environmental impact of such processes. The insights gained shed light on the behavior of PET under γ-irradiation and the resulting impact on microplastic pollution and make an important contribution to our understanding of the broader environmental context.

Gamma-irradiated stibnite thin films set a remarkable benchmark performance for photoelectrochemical water splitting.

The study sets out to show the positive impact of sulfur vacancy engineering on the structural, morphological, optical, electrical, and photoelectrochemical (PEC) properties of Sb2S3 films synthesized using the spin coating technique. The produced films were exposed to γ-irradiation with different doses from 0 to 20 kGy. We have demonstrated the formation of sulfur vacancies and loss of oxygen content in the irradiated samples. XRD measurements revealed that all films exhibit a polycrystalline structure, and the crystallite size increases with the rising radiation dose, reaching the highest value of 87.4 nm measured for the Sb2S3 film irradiated with 15 kGy. The surface roughness of the irradiated samples increases with increasing γ-irradiation dose. The increase in surface roughness not only raises the active sites but enhances the conductivity of the Sb2S3 material as well. The wettability properties of the irradiated films were affected by γ-irradiation doses and the sample irradiated with 15 kGy exhibited the lowest hydrophobicity compared to others. The Hall measurements reveal that irradiated samples exhibit p-type semiconductor behavior. The optical band gap decreased progressively from 1.78 eV to 1.60 eV up to the irradiation dose of 15 kGy and slightly increased thereafter. The irradiated sample with 15 kGy showed a maximum photocurrent density of ca. 1.62 mA cm-2 at 0 V vs. reverse hydrogen electrode (RHE) under AM 1.5 G illumination with applied bias photon-to-current efficiency (ABPE) of 0.82% at 0.47 V vs. RHE, suggesting superior PEC water splitting performance compared to other samples. At 0 V vs. RHE and 648 nm, the incident photon current efficiency (IPCE) and absorbed photon current efficiency (APCE) of the photocathode irradiated with 15 kGy are significantly higher than those of the other photocathodes with values of 9.35% and 14.47%, respectively. Finally, Mott-Schottky measurement was also performed on all photocathodes to estimate their acceptor density and flat band potential.

Abstract 5000: Low dose ionizing radiation elicits the extrusion of neutrophil extracellular traps

Abstract The majority of cancer patients undergo radiotherapy interventions at some point in their clinical management with unintended irradiation of blood vessels. We show that very low γ-irradiation doses (0.5-1 Gy) of human and mouse neutrophils elicit neutrophil extracellular trap (NET) formation in a manner dependent on oxidative stress, NADPH oxidase activity and autocrine interleukin-8. Radiation-induced NETs interfere with NK- and T-cell cytotoxicity-repelling effector lymphocytes away from tumor cells. As a consequence, pre-injection of irradiation-induced NETs increases the number of successful metastases in mouse tumor models. Increases in circulating NETs are readily detected in series of patients following radiotherapy interventions. Our results reveal new mechanisms whose knowledge may help to improve the efficacy and safety of radiotherapy, especially when used in combination with immunotherapy approaches. Citation Format: Alvaro Teijeira, Ana Martinez-Riaño, Beatrice Pinci, Almudena Manzanal, Paula Molero, Maria E. Rodriguez- Ruiz, Ignacio Melero. Low dose ionizing radiation elicits the extrusion of neutrophil extracellular traps [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5000.

Enhancing the potential of rapeseed cake as protein-source food by γ-irradiation.

Rapeseed cake serves as a by-product in the oil extraction industry, characterized by its elevated protein content. However, the presence of antinutritional factors limits the utilization of rapeseed cake as a viable protein source. In this study, different doses of γ-irradiation were used to irradiate rapeseed cake and rapeseed protein isolate was extracted through a modified alkaline solution and acid precipitation method from rapeseed cake. The chemical composition and in vivo acute toxicity of rapeseed protein isolate were determined. The protein recovery rate of rapeseed protein isolate was 39.08 ± 3.01% after irradiation, while the content of antinutritional factors was significantly reduced. Moreover, γ-irradiation did not have any experimentally related effects on clinical observations or clinicopathology in mice. Overall, the reduced antinutrients and increased functional properties suggest that the irradiation of rapeseed cake (<9 kGy) could be utilized as a pre-treatment in the development of rapeseed cake-based value-added protein products.

Effect of apricot kernel seed extract on biophysical properties of chitosan film for packaging applications

Chitosan is a natural biodegradable biopolymer that has drawbacks in mechanical and antibacterial properties, limiting its usage in biological and medicinal fields. Chitosan is combined with other naturally occurring substances possessing biological antibacterial qualities in order to broaden its application. Ethanolic apricot kernel seed extract was prepared, analyzed, and incorporated into chitosan film with different concentrations (0.25, 0.5, and 0.75 wt%). Furthermore, the effect of AKSE and γ-radiation (20 Gy and 20 kGy) on the physical properties of the film was studied. The prepared films were characterized by Fourier transform infrared spectroscopy (FTIR), which revealed that AKSE did not cause any change in the molecular structure, whereas the γ-irradiation dose caused a decrease in the peak intensity of all concentrations except 0.75 wt%, which was the most resistant. In addition, their dielectric, optical, and antimicrobial properties were studied. Also, AKSE-enhanced optical qualities, allowed them to fully block light transmission at wavelengths of 450–600 nm. The dielectric properties, i.e., permittivity (ε′), dielectric loss (ε′′), and electrical conductivity (σ), increased with increasing AKSE concentration and film irradiation. The antimicrobial studies revealed that the antimicrobial activity against Escherichia coli and Canodida albicans increased with AKSE incorporation.

Influence of γ-Irradiation on the Electronic Structure and the Chemical and Mechanical Properties of Poly(hydroxybutyrate-valerate)/Poly(caprolactone) Blends: Insights from Experimental Data and Computational Approaches

In this study, we investigated the influence of γ-irradiation (0, 50, and 100 kGy) doses on the chemical and mechanical properties of biodegradable poly(hydroxybutyrate-valerate)/poly(caprolactone) (PHBV/PCL) polymer blends rich in low-molar-mass PCL, which were prepared using a co-rotating twin-screw extruder. In parallel, the density functional theory (DFT) and the time-dependent DFT (TD-DFT) methods were used together with a model containing four monomer units to provide an insight into the electronic structure, chemical bonds, and spectroscopic (such as Nuclear Magnetic Resonance (NMR) and Ultraviolet-visible (UV-vis)) properties of PHBV and PCL blend phases, which are critical for predicting and designing new materials with desired properties. We found that an increase in γ-irradiation doses caused splitting instead of crosslinks in the polymer chains, which led to evident deformation and an increase in tensile strength at break of 2.0 to 5.7 MPa for the PHBV/PCL blend. Further, this led to a decrease in crystallinity and proved the occurrence of a more favorable interaction between the blend phases.

Pre-sowing irradiation of annual ryegrass seeds as a way to accelerate plant growth and adaptation to adverse conditions

As a result of pre-sowing irradiation of annual ryegrass seeds of Rapid variety, the effect of radiobiological stimulation was obtained, which manifested in root growth and an increase in the mass of seedlings and was most observed at a dose of γ-irradiation of 4 Gy. A similar effect when germinating seeds after storage for 90 days was obtained at higher doses of seed irradiation – 10 and 15 Gy; a dose of 4 Gy increased the sprout length. In case of imitation of arid conditions for ryegrass plants, seedlings from non-irradiated seeds of the control variant, under stress, experienced depression and lagged in growth from seedlings with optimal hydration. At the same time, pre-sowing γ-irradiation of seeds in doses of 15-20 Gy partially compensated for the negative effect of lack of moisture, ensuring the same plant development as with optimal hydration, confirming that radiation hormesis can be an example of an adaptive reaction to changing environmental conditions.

Combined effect of γ-irradiation and antibacterial formulations based on natural compounds for preservation of mother's milk

The antibacterial potential of citrus extract, EOs (mediterranean formulation, oregano, lemongrass, cinnamon and clove), organic acids and salts (citric acid, lactic acid and sodium carbonate) was evaluated against E. sakazakii, E. coli O157:H7, S. aureus, L. monocytogenes, S. Typhimurium, B. cereus by determining the minimal inhibitory concentration (MIC). Based on the results, MIC value ranges from 312.5 to 5000 ppm against tested bacterial strains, with citrus extract showing the highest antibacterial activity (312.5 ppm). Four antimicrobial formulations based on quaternary combination of compounds were developed based on the fractional inhibitory concentration (FIC) index. Formulation 1 (Oregano/Mediterranean formulation/Citrus extract/Lactic acid), Formulation 2 (Cinnamon/Lemongrass/Citrus extract/Citric acid), Formulation 3 (Oregano/Mediterranean formulation/Citrus extract/Citric acid), Formulation 4 (Cinnamon/Lemongrass/Citrus extract/Lactic acid) showed a synergistic effect against all tested pathogens. Results demonstrated that bacterial radiosensitivity (1.34–3.99) was increased by the combined treatment of γ-irradiation with developed formulations in frozen mother's milk. Formulation 3 and 4 induced greater radiosensitivity in bacterial strains including sporulated B. cereus (1.90 and 1.89 respectively) compared to formulation 1 and 2. Therefore, the combined treatment can be an effective method to reduce the γ-irradiation dose (kGy) required to eliminate the pathogens and assures the safety of frozen mother's milk.

Storage Stability Assessment of Indigenous Guava Fruits (Psidium guajava L.) cv. “Gola” in Response to γ-Irradiation

Postharvest losses in fruits and vegetables pose a key challenge to the global horticulture industry. Improved storage stability of horticultural commodities through irradiation is a technological intervention which has greater compliance over more than 60 foods and food products. The present study was intended to explore the effect of γ-irradiation doses on the postharvest quality of fresh guava fruits stored under ambient (temperature 20 ± 2 °C, RH 85%) conditions. Various storage specific quality attributes including physiological weight loss, respiration rate (CO2), ethylene estimation, ripening index, fruit firmness, ascorbic acid, nutraceutical potential, and enzyme kinetics were evaluated during postharvest storage at four days of interval. The results indicated that the fruits irradiated at doses (0.8 kGy and 1.0 kGy) exhibited significant reduction in physiological parameters in contrast with untreated fruit samples. Firmness, total phenolic compounds, flavonoids, and radical scavenging activity were successfully retained in irradiated fruit samples up to twenty days of storage. The respiration and ethylene production rates were suppressed in irradiated guava fruits compared to control. Moreover, it has also been discovered that the fruits exposed to 1.0 kGy had considerably decreased the polyphenol oxidase (PPO) activity compared to nonirradiated fruits, thus resulting in lowering the enzymatic browning. Aside from that, irradiation guava fruits had considerably enhanced antioxidant enzyme activity ( P ≤ 0.05 ) in terms of catalase, peroxidase, and superoxide dismutase. In conclusion, the study revealed that γ -rays irradiation doses up to 1.0 kGy might be considered effective to improve the postharvest storage of native guava fruits variety with intact nutritional attributes.

Rheological Properties of Gel Systems Based on Gamma-Irradiated Lightly Crosslinked Polyacrylic Acid

The effect of γ-irradiation of the gelling agent Carbomer 141 G, which is lightly crosslinked polyacrylic acid, on the rheological properties of gels based on the carbomer has been studied. It has been found that an increase in the dose of γ-irradiation in air has a destructive effect on the polymer, leading to a decrease in rheological parameters, such as viscosity, yield strength, and hysteresis area. Irradiation of the carbomer in air with doses greater than 300 kGy leads to a significant decrease or the complete loss of its gel-forming properties. At the same time, irradiation of the carbomer with the same dose in vacuum causes as small a decline in viscosity as 2% compared to the initial systems. It has been established that the optimal gelling agent for obtaining stable antibacterial gels is the carbomer irradiated with a dose of 30 kGy.

Gamma–radiation synthesis and characterization of nanocomposite hydrogels based on poly(vinyl-alcohol)/zirconium NPs/ europium

In the present work, nanocomposite hydrogels based on poly(vinyl-alcohol)/zirconium NPs/europium (PVA/ZrO2NPs/Eu3+) hybrid films were prepared by solution casting technique and then exposed to gamma irradiation (0–65 kGy). Zirconium oxide (ZrO2) nanoparticles (NPs) doped with 5mole% Eu3+ were prepared via sol gel technique. The polymer nanocomposite films were characterized by X-ray Diffraction (XRD) analysis, Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). Furthermore, the PVA/ZrO2/Eu3+ nanocomposites were characterized for their optical properties using UV–Vis–NIR and photoluminescence (PL) spectroscopy. XRD analysis confirms the formation of ZrO2 monoclinic phase with the nanometer size (20 nm–11nm) when the γ-dose increases from 0 to 25 kGy respectively. Phase transition from monoclinic to tetragonal structure with an average particles size about 25 nm was observed when the γ-irradiation dose reaches 35 kGy. Increasing of γ-dose up to 65 kGy, a remarkable decrease in peaks intensity was observed and reappearance of the monoclinic ZrO2 phase again with average particle size about 10 nm. FTIR peaks intensity changes with increasing γ-irradiation doses. SEM observations showed that the nanocomposite film prepared at 35 kGy inhibits the agglomeration of ZrO2:Eu3+ nanoparticles in PVA host. The optical band gap energy decreases with increasing of γ-dose. PL measurements do not show any emission in the nanocomposite up to 25 kGy. However, at 35 kGy the sample exhibits characteristic orange-red emission centered at 607 nm attributed to 5D0→7F2 transition of Eu3+ ions. Further increasing of γ-dose up to 65 kGy, PL peaks intensity decreases drastically.

Potential impact of mesenchymal stem cells on nephrotoxicity induced by gamma irradiation and antiepileptic drugs cotherapy in rats.

The goal of this study was to assess the influence of bone marrow-derived mesenchymal stem cells (BM-MSCs) on the nephrotoxicity induced by fractionated doses of gamma irradiation (Rad) and the cotherapy of levetiracetam and oxcarbazepine in male rats. Adult rats were randomly divided into four groups. Group I: Control, Group II: antiepileptic drugs (AEDs), Group III: AEDs +Rad and Group IV: AEDs + Rad + MSCs. Rats treated with AEDs and exposed to fractionated doses of γ-irradiation displayed a discernible increase in serum urea, creatinine, kidney injury marker, kidney malondialdehyde, transforming growth factor beta (TGF-β) and the relative expression of Smad3 along with a decrease in the relative expression of Smad7 and glutathione level. Alternatively, groups treated with BM-MSCs with AEDs and Rad showed a substantial modification in the majority of the evaluated parameters and looked to be successful in reducing the hazards of the combination therapy of AEDs and radiation. The reno-histopathological study supports the biochemical analysis. In conclusion, BM-MSCs exhibited therapeutic potential against nephrotoxicity induced by fractionated doses of γ-irradiation and AEDs. The outcome was brought about by the downregulation of the TGF-β/Smad pathway. BM-MSCs might be suggested as a valuable therapeutic strategy to overcome kidney injury induced by gamma irradiation during AEDs cotherapy.

Effect of Gamma-Irradiation Dose on the Yield and Acute Toxicity of Seed Potato Tubers of the Meteor Variety

The influence of the dose of presowing γ-irradiation of tubers on the anatomical and morphological structure, yield, and tasting properties of potatoes of the Meteor variety has been studied. Morphological disorders—beak-shaped and heart-shaped tubers of a large fraction and small tubers in the form of embryos—were found in potatoes grown from tubers irradiated with doses of 500–600 Gy, although no external anatomical and morphological differences were noted in the stems and leaves of potato plants in the course of the vegetative development regardless of the presowing irradiation dose of tubers. Irradiation of seed tubers with doses of 200–300 Gy led to the highest yield and profitability and the best tasting qualities of grown potatoes. Experiments on the toxicity of potato tubers irradiated with doses of 100–1500 kGy and juice released during their radiolysis with doses of 1200–5000 kGy showed no negative effect on the animals that consumed them. At the same time, the physiological processes of digestion, excretion, and metabolism in experimental animals were not inhibited and the level of glucose in their blood remained within physiological reference values. The experimentally established highest doses of γ-irradiation of potatoes and the doses of introducing aqueous dispersions of the irradiated products into mice (gram of substance per 1 kg of live weight of the animal) that did not cause clinical manifestations were 10 g/kg for powdered potato tubers irradiated with a dose of 1500 kGy and 20 g/kg for dried juice powder released in the course of irradiation of potato tubers with a dose of 2000 kGy.

Nanostructure CuO thin film deposited by spray pyrolysis for technological applications

Nanostructured thin films of copper oxide (CuO) were deposited using a facile spray pyrolysis approach on glass substrates at controlled temperature setting of 400 °C. The creation of pure polycrystalline CuO with a tenorite transition, which has a monoclinic structural that is very viable for super-capacitors, was revealed by the X-ray diffraction analysis. The crystal structure of CuO film was improved with the γ-irradiation doses with a preferred orientation along (−111) before and after the irradiation. CuO thin film has a direct optical band gap according to the optical measurements, which generally increases with the gamma irradiation dose. The optical constants such as the dielectric constant's real and imaginary parts as well as the optical conductivity, the extinction coefficient, the refractive index, and the absorption coefficient have been measured and their values also decrease with the increase in irradiation dose. Utilizing cyclic voltammetry in a 1M KOH electrolyte, which demonstrates a maximum specific capacitance of 192.20 Fg-1 at a scan rate of 5 mVs−1, the electrochemical amazingly capabilities of CuO thin films were assessed. Importantly, CuO electrode impedance studies reveal that CuO is a viable material for super-capacitor applications.

Modeling and optical characterization of γ-irradiated Cu2+Doped borate glasses as bandpass optical filters

Novel systems of alkali borate glasses with various CuO concentrations from 0.2 up to 1.5 mol% have been prepared by the conventional melt-quenching technique. Several optical, physical, and structural characteristics of the prepared glasses have been examined before and after incremental γ-irradiation doses. The intensity of the blue color of the glasses is controlled by CuO concentrations, with Cu+/Cu2+ in ionic equilibrium. UV/Vis absorption peaks centered at 740 nm can be correlated to a tetragonal twist of the octahedral structure due to 2B1g-2B2g electronic transition. Photoluminescence (PL) extinction spectra can be attributed to Cu+-Cu+ energy migration after Cu+→ Cu2+ energy transfer. Electron spin resonance (ESR) measurements show sharp signals at magnetic fields ranging from 3344 to 3326 Gauss (g = 2.08–2.09), corresponding to the divalent copper state (Cu2+) in octahedral units. FTIR spectra revealed stable structures towards irradiation. Either an increase in CuO content or irradiation led to greater UV absorption, lower PL intensity, lower bandgap (Eopt), lower density, larger molar volume, and slightly more intense ESR signals. Copper ions can be considered as modifiers since they increase the degree of disorder in the glassy network. UV/NIR band stop, FWHM, and center of peaks confirmed the high efficiency of the prepared Cu-doped glasses as colored optical bandpass filters in the green and near-blue regions for UV/IR light laser protection.

Investigating into physical properties of composites of polymer blends and cobalt chloride irradiated by gamma ray for optical devices development

The present work studies the influence of cobalt chloride (CoCl2) and γ-irradiation dose on the optical, thermal properties, and dynamic mechanical analysis (DMA) of different blends of (PVA/PEG /PVP). Different optical parameters were deduced before and after γ-irradiation with different doses (5, 10, and 15 kGy). The optical conductivity (σoptical) values for the prepared blends and composites indicate their importance for optical energy applications, especially after γ-irradiation. Modifying and enhancing the refractive index of γ-irradiated samples enables their use in various optical devices. Linear optical susceptibility (χ(1)) and the third nonlinear susceptibility (χ(3)) increased by decreasing the PVA amount in the blend and composites. Thermogravimetric analysis TGA confirmed that by adding CoCl2 to the hosting blends, the thermal oxidative degradation energy Ea became much higher than unirradiated samples. The DMA results show that the storage modulus was significantly improved after adding CoCl2 and after irradiating the samples by 5 and 10 kGy. Also, all the samples exhibited two relaxation temperatures and were greatly affected by adding the filler.

Effect of high γ-irradiation dosage on physico-chemical, functional and emulsion properties of almond gum powder

Almond gum is a natural biopolymer produced by Almond tree that is non-toxic, biodegradable, and biocompatible. These features make it suitable for applications in the food, cosmetic, biomedical, and packaging industries. To ensure its wide application in these fields, green modification process is necessary. Gamma irradiation is often used as a sterilisation and modification technique, due to its high penetration power. Thus, evaluating its effects on the physicochemical and functional properties of gum after exposure is important. To date, limited studies have reported the use of high dose of γ-irradiation on the biopolymer. Therefore, the present study demonstrated the effect of a high dose of γ-irradiation (0, 24, 48, and 72 kGy) on the functional and phytochemical properties of almond gum powder. The irradiated powder was studied for its color, packing, functional, and bioactive properties. The results revealed a significant increase in water absorption capacity, oil absorption capacity, and solubility index. However, a decreasing trend was observed in the foaming index, L value, pH, and emulsion stability with the radiation dose. Besides, sizable effects were observed in the IR spectra of irradiated gum. Phytochemical properties were significantly improved with an increase in dose. The emulsion was prepared from irradiated gum powder, where the highest creaming index was observed at 72 kGy and a decreasing trend in zeta potential. These results suggested that γ-irradiation treatment is a successful method to generate desirable cavity, pore sizes, functional properties, and bioactive compounds. This emerging approach could modify the natural additive with distinct internal structure for specific uses in wide range of food, pharmaceutical and other industrial applications.

The influence of γ-irradiation on molecular structure and mass attenuation coefficients of γ-Al2O3 nanoparticles

In this research, γ-Al2O3 nanoparticles (NPs) were synthesized by using the sol–gel process. The photon attenuation properties of these NPs were obtained by measuring the linear and mass attenuation coefficients (μl, μm) at different photon energies. In addition, the theoretical values of μm for γ-Al2O3 micro-particles were calculated using the WinXCom computer program and compared with the experimental values of μm for NPs of γ-Al2O3. Furthermore, in order to evaluate the impact of γ-irradiation on these NPs, the experimental values of μl and μm for γ-Al2O3 NPs, before and after receiving 20 kGy dose of γ-irradiation, were investigated. It was observed that μm of γ-Al2O3 NPs decreases after receiving γ-irradiation because of increasing the photon’s energy, which indicates the changes in the molecular structure of NPs after γ-irradiation. Moreover, the structural properties of NPs were evaluated by UV–Vis spectroscopy, x-ray diffraction patterns, and scanning electron microscopy images. UV–Vis spectroscopy showed an absorption peak at 212.5 nm before γ-irradiation, and the absorption peak of NPs disappeared when γ-irradiation was started. The average crystalline size was determined to be 3.65 nm in the sample before γ-irradiation and 9.29 nm in the sample with the maximum dose of 20 kGy. The results of scanning electron microscopy show an increase in particle size from 6.5 nm in a non-irradiated sample up to 9 nm in a sample with the highest γ-irradiation dose.