| 1. |
- El Hachmi, A., et al.
(författare)
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Structural, Magnetic and Optical Properties Study of Tellurium-Based Perovskites : Sr3-xPbxFe2TeO9 (0 <= x <= 2.25)
- 2020
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Ingår i: JOURNAL OF INORGANIC AND ORGANOMETALLIC POLYMERS AND MATERIALS. - : Springer Science and Business Media LLC. - 1574-1443 .- 1574-1451. ; 30:6, s. 1990-2006
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Tidskriftsartikel (refereegranskat)abstract
- Polycrystalline samples of the series of triple perovskites Sr3-xPbxFe2TeO9 (0 <= x <= 2.25) (SPFTO) were synthesized using solid state reaction. These materials have been studied by a combination of X-ray powder diffraction (XRPD), Mossbauer spectrometry, Raman and UV-Vis spectroscopies. The crystal structures were resolved by the Rietveld refinement method, and revealed that this Sr3-xPbxFe2TeO9 (0 <= x <= 2.25) system shows one space group change from tetragonal I4/m (0 <= x <= 1) to another tetragonal form I4/mmm (1.25 <= x <= 1.88) and a second transition to hexagonal R3 over bar m (2.08 <= x <= 2.25). An anti-site disordering of Fe and Te on the B sites has been detected indicating the presence of a partial amount of Te at Fe positions and vice versa. The valence state of iron in the Fe site was determined to be Fe(III) by Mossbauer spectrometry, which also revealed two sites in a concordance with the XRPD measurements. Fe-57 Mossbauer spectra measurements show paramagnetic and magnetic ordering behaviors. The observed Raman spectra as a function of composition show obvious changes on the positions (wavenumbers), the FWHM and the intensities of the modes confirming the phase transformations observed by the XRPD results. These structural transitions led to a distinct change in the optical band gap energy, varying from 2.14 to 1.85 eV.
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| 2. |
- Jerroudi, M., et al.
(författare)
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Investigation of Novel Low Melting Phosphate Glasses Inside the Na2O-K2O-ZnO-P2O5 System
- 2020
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Ingår i: JOURNAL OF INORGANIC AND ORGANOMETALLIC POLYMERS AND MATERIALS. - : SPRINGER. - 1574-1443 .- 1574-1451. ; 30:2, s. 532-542
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Tidskriftsartikel (refereegranskat)abstract
- Phosphate glasses containing different concentrations of zinc oxide inside the (1 - x)(NaPO3-KPO3)-xZnO system (0 <= x <= 50 mol%) have been prepared using the conventional melt quenching technique. The prepared glasses were transparent, bubble-free and colourless. Their density, molar volume, glass transition temperature, and structural properties using infrared and Raman spectroscopies are investigated. As the content of ZnO increases, the density increases while the molar volume decreases. The composition dependence of T-g shows a minimum for the glass (x = 20 mol%). Structural approach realized by IR and Raman spectroscopies reveals that zinc ions occupy different sites in the glassy-network, mainly modifier sites and middle phosphate network in low-zinc and high-zinc glasses, respectively. The introduction of ZnO in the network induces some structural rearrangements through the conversion of metaphosphate structural units to pyrophosphate ones. It is also highlighted that the presence of ZnO in the glassy matrix allows the transformation of some P-O-P and P=O bonds to P-O-Zn linkages. From the UV-Visible absorption studies, the values of the optical band gap, E-g, and Urbach energy, Delta E, were evaluated. The optical band gap is found to depend on the glasses composition. E-g and Delta E show a minimum and a maximum respectively, for the glass (x = 20 mol%).
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| 3. |
- Sajjad, Anila, et al.
(författare)
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Integration of Zinc Oxide Nanoparticles in Wheat Gluten Hydrolysates-Development of Multifunctional Films with Pliable Properties
- 2023
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Ingår i: Journal of Inorganic and Organometallic Polymers and Materials. - : Springer Nature. - 1574-1443 .- 1574-1451. ; 33:4, s. 914-929
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Tidskriftsartikel (refereegranskat)abstract
- Biodegradable wheat gluten hydrolysates (WGH) and zinc oxide nanoparticles (ZNPs) with cross-linkers were prepared as nanocomposite films. The physiochemical analysis demonstrated the formation of ZNPs of size approximately 18.37 nm with spherical and hexagonal nanostructures. The ZNPs are endowed with different functional groups, as corroborated by X-ray diffractogram (XRD), field emission electron microscopy (FE-SEM), and fourier transform infrared spectroscopy (FT-IR), respectively. XRD and functional group patterns (IR) of WG and ZNPs exhibited minor changes during film development, indicating a successful interaction between the components. The SEM analysis revealed that the integration of ZNPs into the wheat gluten polymer promoted nano-aggregation on the film surface and the cross-section. The swelling capacity of films was found to be highest by WG/PVP/ZNPs with 265% (pH 7) and 198% (at pH 9). The antibacterial assessments revealed the sensitivity of Pseudomonasaeruginosa and E.coli toward WG/PVP/ZNPs with 14 and 13 mm zone of inhibition, demonstrating the maximum release of zinc ions from WG/PVP/ZNPs films. Furthermore, the WG/PVP/ZNPs film exhibits maximum oxidant scavenging (84%) and oxidant quenching potential (75%). The findings suggest that casting of WGH with ZNPs has a remarkable effect on the films’ physical and biological properties, allowing for their potential use as future bioplastics in biomedical and industrial sectors.
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| 4. |
- Dawi, E. A., et al.
(författare)
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Ag/AgCl Decorated Ionic Liquid@Tantalum Pentoxide Nanostructures: Fabrication, Photocatalytic Activity, and Cytotoxicity Effects Against Human Brain Tumor Cells
- 2023
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Ingår i: JOURNAL OF INORGANIC AND ORGANOMETALLIC POLYMERS AND MATERIALS. - : SPRINGER. - 1574-1443. ; 33, s. 2647-2660
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Tidskriftsartikel (refereegranskat)abstract
- Environmental contaminants have become a major concern for human beings due to their adverse effects on drinking water quality. Heterogeneous photocatalysis has been extensively investigated as a potential strategy to minimize the consequences of as-related processes. Using a room-temperature ionic liquid-mediated co-precipitation method, Ag@AgCl nanoparticles were loaded onto tantalum pentoxide to make a plasmonic photocatalyst to remove Congo Red dye. The physicochemical properties of the photocatalysts were characterized by X-ray diffraction powder (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), Diffuse Reflectance Spectroscopy (DRS), Fourier-transform infrared spectroscopy (FTIR), Transmission Electron Microscopy (TEM), photoluminescence (PL), and nitrogen adsorption-desorption isotherms. The results indicate that 96% of the dye was degraded within 20 min with a rate constant of 0.14 min(-1). The key radicals involved in the photocatalysis, recognized as O-2(center dot-) species, were identified by electron spin resonance (ESR) in the presence of 5,5-dimethyl-1-pyrroline-N-oxide (DMPO), as the spin trapping agent. Our findings and quenching experiments elucidates the mechanism of the charge carrier migration. The cytotoxicity activity of the nanostructures was also examined against human brain glioblastoma tumor cells for the first time. A precise analysis of the cell death pathway was conducted using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT), mitochondrial membrane potential (MMP), reactive oxygen species (ROS), and caspase activity assays in combination with fluorescence microscopy images. The prepared nanomaterials were found to be promising candidates for treating the organic pollutants and biomedical waste effluents from academic and industrial activities.
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