Impact of gamma irradiation on physico-chemical and electromagnetic interference shielding properties of Cu2O nanoparticles reinforced LDPE nanocomposite films.

In the current work, cuprous oxide (Cu2O) nanoparticles coated with Tween 80 were successfully synthesized via the chemical reduction method. Nanocomposites composed of low-density polyethylene (LDPE) and different ratios of Cu2O nanoparticles were fabricated by the melt mixing process. 10% of ethyl vinyl acetate (EVA) as a compatibilizing agent was added to the molten LDPE matrix and the mixing process continued until homogenous nanocomposites were fabricated. To study the influence of ionizing radiation on the fabricated samples, the prepared species were exposed to 50 and 100 kGy of gamma rays. The synthesized Cu2O nanoparticles were investigated by transmission electron microscopy (TEM) and X-ray diffraction (XRD). XRD and TEM analysis illustrated the successful formation of spherical Cu2O nanoparticles with an average size of 16.8 nm. The as-prepared LDPE/Cu2O nanocomposites were characterized via different techniques such as mechanical, thermal, morphological, XRD, and FTIR. Electromagnetic interference shielding (EMI) of the different nanocomposite formulations was performed as a promising application for these materials in practical life. The electromagnetic shielding effectiveness (SE) of the produced samples was measured in the X-band of the radio frequency range from 8 to 12 GHz using the vector network analyzer (VNA) and a proper waveguide. All the samples were studied before and after gamma-ray irradiation under the same conditions of pressure and temperature. The shielding effectiveness increased significantly from 25 dB for unirradiated samples to 35 dB with samples irradiated with 100 kGy, which reflects 40% enhancement in the effectiveness of the shielding.

Toxicological, hepato-renal, endocrine disruption, oxidative stress and immunohistopathological responses of chitosan capped gold nanocomposite on Biomphalaria alexandrina snails.

The present investigation aimed to synthesize chitosan­gold nanocomposites (Ch-AuNPs) with gamma radiation, then to evaluate its toxic effect on the freshwater snails Biomphalaia alexandrina. Results showed that Ch-AuNPs is spherical shaped with average size 12 nm. It had a toxic effect against B. alexandrina snails with LC50 20.43 mg/l. Exposure of B. alexandrina snails to LC10 7.51 or LC25 13.63 mg/l of Ch-AuNPs, reduced the survival, reproductive and fecundity rates; total protein and albumin; both testosterone (T) and 17ß Estradiol (E) levels; SOD and CAT activities of exposed snails while increased the activities of transaminases (AST & ALT), uric acid, creatinine, TAC and MDA levels compared to the control group. Results were supported by histopathological and immunohistopathological alterations of the digestive and hermaphrodite glands. In conclusion B. alexandrina could be used as a model to screen the negative impact of nanomaterials. Also, Ch-AuNPs could be used as a molluscicidal agent.

Gamma radiation-induced synthesis of a novel chitosan/silver/Mn-Mg ferrite nanocomposite and its impact on cadmium accumulation and translocation in brassica plant growth.

Herein, a novel chitosan/silver/Mn0.5Mg0.5Fe2O4 (Cs/Ag/MnMgFe2O4) nanocomposite was synthesized with gamma irradiation assistant. The prepared Cs/Ag/MnMgFe2O4 nanocomposite was characterized via EDX, XRD, SEM, UV-vis spectroscopy. To evaluate the effects of soak low and high-dose nanocomposite on physiological parameters, photosynthetic pigments, antioxidant and non-antioxidant enzymes of cabbage under Cd stress, a factorial experiment was conducted based on CRD with five replications. The Cd stress decreased the morphological characteristics and photosynthetic pigments while increasing cabbage's antioxidant and non-antioxidant enzymes. The application of low and high-dose of nanocomposite decreased Cd content in leaves by about 42.86%, 60.48%, and the root by approximately 18.72%, 28.72%, respectively, and translocation factors and tolerance index, H2O2, O2, and malondialdehyde. In contrast, the application of high of the nanocomposite increased the values of SPAD chlorophyll about 27.50%, stomatal conductance about 87.18%, net photosynthetic rate about 44.90%, intercellular CO2 concentration about 32.00%, and transpiration rate about 85.20%, as compared to Cd stress. Furthermore, the application of low and high-dose Cs/Ag/MnMgFe2O4 nanocomposite enhances the antioxidant and non-antioxidant enzymes of the cabbage plant compared to Cd stress. Generally, it was conducted that Cs/Ag/MnMgFe2O4 nanocomposite can be used as a proper tool for increasing cabbage plants under Cd stress.

Radiation-induced synthesis of copper sulfide nanotubes with improved catalytic and antibacterial activities.

In the current paper, copper sulfide nanotubes have been successfully synthesized via the green, simple, and effective gamma-radiolysis method without adding any capping or reducing agents. The structural and morphological characteristics of the as-prepared CuS nanotubes were investigated by X-ray diffraction (XRD), N2 adsorption-desorption measurements at 77 K, transmission electron microscopy (TEM), and ultraviolet-visible (UV-vis) spectroscopy, which all demonstrated the formation of pure CuS covellite phase with tubular morphology. The synthesized CuS nanotubes possessed not only high activity towards the reduction of both cationic (methylene blue) and anionic (Congo red) dyes in the presence of NaBH4 but also exhibited excellent reusability. In addition, the pseudo-first-order kinetic model represented the reduction of MB very well, and the value of the normalized rate constant (2.4 × 10-2 s-1 mg-1) was higher than those of other solid catalysts reported in the literature. Ultimately, CuS nanotubes were found to have a broad-spectrum microbicidal action against the common microbiota, such as Gram-positive (exemplified by Bacillus subtilis and Staphylococcus aureus), Gram-negative bacteria (exemplified by Pseudomonas aeruginosa and Escherichia coli), yeast (exemplified by Candida albicans), and plant pathogenic fungi (exemplified by Aspergillus niger).

Radiation-induced synthesis of tween 80 stabilized silver nanoparticles for antibacterial applications.

Recently, Silver nanoparticles (AgNPs) have become widely applied nanomaterial in human contacting areas such as cosmetics, food and medicine due to their antibacterial property. On the other hand, surfactants are essential ingredient of several industrial and consumer formulations. Based on these important applications, the current research was aimed to carry out the synthesis and characterization of Tween 80 capped silver nanoparticles (T80-AgNPs) using gamma radiation reduction method. Characterization of T80-AgNPs was occurred by using UV-Vis, XRD, FTIR and TEM techniques. UV-Visible spectra showed surface plasmon resonance (SPR) peak in the range of 420 nm signifying the synthesis of colloidal AgNPs. TEM confirmed the formation of spherical and uniformly distributed AgNPs with average size of 18 nm. XRD analysis illustrated the formation of pure crystalline AgNPs. The FTIR analysis provides evidence for the stabilization of AgNPs by Tween 80. The synthesized T80-AgNPs were evaluated for antibacterial activity against both Escherichia coli (E. coli) as gram negative (G -ve) bacteria and Staphylococcus aureus (S. aureus) as gram positive (G + ve) bacteria and anti-biofilm activity to P. aeruginosa. The results show that T80-AgNPs exhibits excellent antibacterial and antibiofilm activities.