Gamma irradiation induced surface modification of (PVC/HDPE)/ZnO nanocomposite for enhancing the oil removal and conductivity using COMSOL multiphysics.

Blend nanocomposite film was prepared by loadings of irradiated ZnO in ratios of (5 wt%) inside the PVC/HDPE matrix using a hot-melt extruder technique. The physical and chemical properties of the irradiated and unirradiated ZnO samples are compared. The Vis-UV spectrum of ZnO shows an absorption peak at a wavelength of 373 nm that was slightly red-shifted to 375 nm for an irradiated sample of ZnO at a dose of 25 kGy due to the defect of crystal structure by the oxygen vacancy during gamma irradiations. This growth of the defect site leads to a decrease in energy gaps from 3.8 to 2.08 eV. AC conductivity of ZnO sample increased after the gamma irradiation process (25 kGy). The (PVC/HDPE)/ZnO nanocomposites were re-irradiated with γ rays at 25 kGy in the presence of four different media (silicon oil, sodium silicate, paraffin wax and water). FTIR and XRD were performed to monitor the changes in chemical composition. The new peak at 1723 cm-1 attributed to C=O groups was observed in irradiated (PVC/HDPE)ZnO samples at only sodium silicate and water media. This process induced new function groups on the surface of the (PVC/HDPE)/ZnO blend sample. This work aims to develop (PVC/HDPE)ZnO for oil/water separation. The highest oil adsorption capability was observed in samples functionalized by C=O groups based on the different tested oils. The results suggest that the surface characterization of the (PVC/HDPE)/ZnO can be modified to enhance the oil adsorption potential. Further, the gamma irradiation dose significantly enhanced the AC conductivity compared to the unirradiated sample. According to COMSOL Multiphysics, the irradiated sample (PVC/HDPE)ZnO in water shows perfect uniform electric field distribution in medium voltage cables (22.000 V).

Gamma radiation synthesis of a novel amphiphilic terpolymer hydrogel pH-responsive based chitosan for colon cancer drug delivery.

Particularly, chitosan (Cs) loaded with drug cannot pass through the colonic region, often leading in the bursting drug release in the stomach due to its solubility in gastric contents. The novelty of the current article is to solve this limitation by performing gamma irradiation cross-linking of Cs with two anionic polymers of (acrylic acid)-co-(2-acrylamido-2-methylpropane-sulfonic acid) (AAc/AMPS) to give amphiphilic hydrogel. The shifted in the characteristic FTIR peaks of Cs in the (Cs/AAc/AMPS) confirm the exits of inter-molecular interactions that make Cs and (AAc/AMPS) are miscible. Swelling experiments under different pH indicated that the (Cs/AAc/AMPS) hydrogels were significantly sensitive to pH change. The results give the possibility to use the obtained (Cs/AAc/AMPS) hydrogel on drug delivery system. The in vitro Fluorouracil (5-FU) releasing from (Cs/AAc/AMPS) matrix was examined under the influence of pH1 and pH7.The results confirmed the hydrogels capability to release 96 % of 5-FU drug at pH 7 after 7 h.

Antimicrobial, antioxidant and anticancer activities of zinc nanoparticles prepared by natural polysaccharides and gamma radiation.

Aqueous dispersed zinc nanoparticles (ZnNPs) were synthesized using natural polysaccherides (chitosan (CS), citrus pectin (CP) and alginate (Alg)) using aqueous fermented fenugreek powder (FFP) by Pleurotus ostreatus as reducing and stabilizing agent or using gamma irradiation. The synthesized ZnNPs are characterized by ultra violect spectroscopy (UV), Transmission electronmicroscopy (TEM), Dynamic light scattering (DLS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). XRD analysis of the ZnNPS confirmed the formation of metallic nanoparticles. The nucleation and growth mechanism of ZnNPs is also discussed. TEM showed that the average diameter of ZnNPs was in the range of 46nm. The size of nanoparticles is influenced by certain parameters such as the choice of stabilizer, pH during synthesis and absorbed dose. Evaluating the antioxidant and anticancer activities of ZnNPs was performed. The results indicating the ZnNPs synthesized by aqueous fermented fenugreek extract have high activity and the average size is 46nm. The results explored that ZnNPs show anticancer activity against Ehrlich Ascites Carcinoma (EAC) and human colon adenocarcinoma (CACO) and the IC50% was 47.5µg/ml and 65µg/ml respectively. Also, ZnNPs had excellent bactericidal activity against gram positive and negative bacteria and yeast.

Radiation induced crosslinking of polyacrylamide incorporated low molecular weights natural polymers for possible use in the agricultural applications.

Superabsorbent hydrogels based on polyacrylamide (PAAm) and Na-alginate (Alg) or chitosan (CS) were synthesized by γ-rays. The effect of dose and copolymer composition on gel content and water absorbency of PAAm/Alg, PAAm/CS and PAAm/Alg/CS hydrogels were studied. The gel content and water absorbency follows the order PAAm/Alg>PAAm/Alg/CS>PAAm/CS. The effect of different cations, fertilizers, buffers on water absorbency of the hydrogels was investigated. Water retention capability of swollen hydrogels as a function of time was studied. PAAm/Alg hydrogel has a high water retention capability. An application of the prepared hydrogels in agricultural fields was performed using maize plants. The results showed that the presence of hydrogels had growth promotion effect on quality and quantity of maize plants. The plants treated by PAAm/Alg hydrogels showed 50% increase in the grain yield suggesting their possible use as a soil conditioner and a water reservoir for plant-soil system.

Phosphorylation of chitosan/HEMA interpenetrating polymer network prepared by γ-radiation for metal ions removal from aqueous solutions.

Interpenetrating polymer network (IPN) hydrogels, based on chitosan (CS) and 2-hydroxyethyl methacrylate (HEMA), have been prepared by γ-radiation followed by chemical modification via phosphorylation reaction and used for adsorption of Ca(II), Cu(II) and Zn(II) ions from their aqueous solutions. The gel content (%) increases with increasing the HEMA concentration. The maximum swelling (%) observed at the ratio (70/30) (CS/HEMA). CS/pHEMA IPN showed a higher thermal stability than CS. The phosphorylated hydrogel, Phos-(CS/pHEMA), characterized by XRD, EDS, SEM, DSC and TGA techniques. FT-IR spectra before and after adsorption of metal ions have been studied. Factors affecting the maximum adsorption capacity were also investigated. The maximum adsorption capacity using 0.01g Phos-(CS/pHEMA) was 66.3, 57.6 and 48.7 (mg/g) for Cu(II), Zn(II) and Ca(II) ions, respectively. The adsorption isotherms were simulated by Langmuir and Freundlich models and the adsorption kinetics were simulated by the pseudo-first-order and pseudo-second-order kinetics. The adsorption follows Langmuir models and pseudo-second order. The IPN hydrogels showed effective adsorption of the three metal ions from aqueous solution.

Preparation, characterization and biodistribution in quails of 99mTc-folic acid/chitosan nanostructure.

Chitosan (CS) of low molecular weight is prepared using γ-irradiation method in presence of H2O2 as oxidizing agent. The chemical treatment of folic acid (FA) with low molecular weight CS is carried out to prepare FACS complex based on the reaction between NH2 group of CS and γ-COOH group of FA. The structure and properties of FACS complex was characterized by FT-IR, 1H NMR, UV, SEM, TEM, DLS and XRD analyses. TEM and DLS results showed that FACS complex has nanostructure and the mean size of particles was unimodal with average diameters in the range of 165-252nm. Radiolabeling of FACS complex (99mTc-FACS) was done with Technetium-99m (99mTc). The optimum conditions of labeling were investigated. The labeling yield was 85% at pH=6 and 30min reaction time. The effect of time on the stability of 99mTc-FACS complex was studied and the results revealed that it is stable up to 6h after labeling. Biodistribution studies of 99mTc-FACS complex in Quail showed that it distributed to different organs mainly in blood, liver and kidney. The results revealed that the uptake of 99mTc-FACS in the sexual organs (ovary and ovarian) of female Quail was higher than that in the sexual organs (testes) of male Quail, so 99mTc-FACS could be used to differentiate between them. It also showed that FACS is consumed and more essential in female than that in male.

Gamma irradiated chitosan and its derivatives as antioxidants for minced chicken.

Ionizing radiation and oxidizing agent like H2O2 were used to degrade chitosan (CS) and its derivatives; N-maleoylchitosan (NMCS), and N-phthaloylchitosan (NPhCS). The structure changes were detected using gel permeation chromatography (GPC). The results revealed that ionizing radiation degraded CS, MNCS, NPhCS and altered their molecular weights and antioxidant activity. The higher the irradiation dose, the lower the molecular weight and the higher antioxidant activity. The addition of irradiated CS and NMCS to minced chicken resulted in highly significant reduction in malondialdehyde (MDA) content (50 and 70%, respectively) if compared with the control. The irradiated NMCS toxicity study did not show strong proliferative effect at small concentrations or cytotoxic effects at higher concentrations. The obtained results suggested that CS and NMCS could be used as natural antioxidant for improving the oxidative deterioration of minced chicken during refrigerated storage.

Effect of γ-rays on carboxymethyl chitosan for use as antioxidant and preservative coating for peach fruit.

Carboxymethyl chitosan (CMCS) was synthesized by alkylation of chitosan using monochloroacetic acid and characterized by FTIR and (1)H-NMR spectroscopies. Different molecular weights (Mws) of CMCS were prepared by radiation degradation of CMCS in the solution form at different irradiation doses. The structural changes and Mw of degraded CMCS were confirmed by UV-Vis, FTIR and GPC. The antioxidant activity of CMCS was evaluated using scavenging effect on DPPH radicals, reducing power and ferrous ion chelating activity assays. The antioxidant activity of CMCS enhanced with decreasing CMCS Mw. The possible practical use of CMCS as preservative coating for peach fruit by dipping treatment after 10 days of storage at ambient temperature was investigated. The CMCS with lower Mw had a good effect on delaying spoilage and decreasing malondialdehyde (MDA) content of peach fruits suggesting their possible use as antioxidant and preservative coating.

Improvement of antioxidant activity of chitosan by chemical treatment and ionizing radiation.

Modification of chitosan (CS) to N-maleoylchitosan (NMCS), N-phthaloylchitosan (NPhCS) and sulfonated-chitosan (SCS) was done using maleic anhydride, phthalic anhydride and chlorosulfonic acid, respectively followed by exposing them to γ-rays at different doses. The molecular weights and structural changes of irradiated chitosan derivatives were determined by GPC, FT-IR and UV-vis spectrophotometer. The molecular weights decreased with increasing irradiation dose. Results revealed that the main polysaccharide structure remained after irradiation. To investigate the enhancement of antioxidant activity of chitosan and its derivatives of different molecular weights, radical mediated lipid peroxidation inhibition, scavenging effect of DPPH radicals, reducing power and ferrous ion chelating activity assays were used. Chitosan derivatives with different molecular weights exhibit antioxidant activity. The lower the molecular weights of chitosan and its derivatives, the higher the antioxidant activity. NMCS possessed high scavenging effect on DPPH radicals compared with NPhCS, SCS and ascorbic acid. The irradiated chitosan and its derivatives could be used as natural antioxidants.