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1.
Sci Rep ; 13(1): 19592, 2023 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-37949900

RESUMO

Mosquitoes still pose a clear risk to human and animal health. Recently, nanomaterials have been considered one of the cost-effective solutions to this problem. Therefore, alumina nanoparticles (Al) were synthesized using an auto-combustion method, followed by calcination at 600 and 800 °C. Glucose (G) and sucrose (Su) were used as fuels and the combustion was performed at pH 2, 7, and 10. The as-synthesized Al2O3 nanoparticles were characterized by XRD, FTIR, SEM, and TEM. Alumina nanoparticles prepared using G and Su fuels at pH 7 and 800 °C (Al-G7-800 and Al-Su7-800) have crystallite sizes of 3.9 and 4.05 nm, respectively. While the samples (Al-G7-600 and Al-Su7-600) synthesized at pH 7 and 600 °C were amorphous. The prepared alumina nanoparticles were applied to the larval and pupal stages of Culex pipiens. The results showed that alumina nanoparticles cause higher mortality in the 1st larval instar than in all other larval instars and pupal stages of Culex pipiens after treatment at a high concentration of 200 ppm. Additionally, the larval duration after treatment with LC50 concentrations of alumina (Al-G7-800 and Al-Su7-800) was 31.7 and 23.6 days, respectively, compared to the control (13.3 days). The recorded data found that the content of glutathione-S-transferase, alkaline/acid phosphatase, ß/α-esterase, and total protein were altered upon treatment with the LC50 concentration of alumina (Al-G7-800) nanoparticles. Based on these findings, alumina nanoparticles are a promising candidate as a potential weapon to control pests and mosquitoes.


Assuntos
Culex , Inseticidas , Nanopartículas , Animais , Humanos , Inseticidas/química , Prata/química , Larva , Pupa/metabolismo
2.
Environ Technol ; 44(17): 2581-2596, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35094670

RESUMO

We herein report the synthesis of monoclinic calcium aluminate (CaAl2O4) nanoparticles via a facile auto-combustion method followed by calcination. We performed the auto-combustion method using aluminium nitrate and calcium nitrate as oxidants and different fuels as reductants such as urea, glycine, and a mixture of urea and glycine, with various fuel-to-oxidant equivalence ratios (Φc). Then, the combusted samples were calcined at different temperatures; 600 and 800 °C. The products were characterized by means of X-ray diffraction, Fourier transform infrared spectroscopy, thermo-gravimetric analysis, field-emission scanning electron microscope, and high-resolution transmission electron microscope. CaAl2O4 nanoparticles with an average crystallite size of 40.4, 38.8, and 33.7 nm were obtained after calcination at 800 °C using the aforementioned fuels, respectively. TEM images revealed that CaAl2O4 nanoparticles tend to form partially sintered aggregates owing to the high thermal treatment temperature, so they have non-uniform shapes. The produced CaAl2O4 nanoparticles exhibited good absorptivity toward Ni(II) and As(III) ions form aqueous media. The maximum sorption capacities (qm) of CaAl2O4 for the removal of Ni(II) and As(III) were found to be 58.73 and 43.9 mg.g-1, at pH 7 and 5, respectively. The equilibrium isotherms and adsorption kinetics studies revealed that the adsorption data fitted well Freundlich isotherm and pseudo-second-order models, respectively. Besides, the adsorption of Ni(II) and As(III) ions on CaAl2O4 nanoparticles is physisorption. Overall, the obtained results indicated that calcium aluminate nano-adsorbent is a good candidate for the removal of Ni(II) and As(III) ions from wastewater, due to its high efficiency, stability, and re-usability.


Assuntos
Nanopartículas , Águas Residuárias , Íons/química , Compostos de Alumínio , Nanopartículas/química
3.
RSC Adv ; 12(38): 25081-25095, 2022 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-36199874

RESUMO

We herein report the controllable synthesis of spherical cobalt ferrite nanoparticles with average crystallite size in the range of 3.6-12.9 nm using a facile, eco-friendly, hydrothermal method. The hydrothermal treatment was carried out by utilizing cobalt nitrate, ferric nitrate, and ammonium hydroxide in the presence and absence of Arabic gum as a surfactant agent. The purity and crystallinity of the products were tuned by varying reaction conditions such as reaction time (0.5-8 h), reaction temperature (120-180 °C), percentage of ethylene glycol (0-100% (v/v)), pH (8-9.6), and amount of Arabic gum (0-2 g). We characterized the prepared products using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FT-IR), high-resolution transmission electron microscopy (HR-TEM), energy-dispersive X-ray spectroscopy analysis (EDS), selected area electron diffraction (SAED) patterns, and UV-visible diffuse reflectance spectra (DRS). The optimal hydrothermal treatment was performed at 180 °C and pH 9.6 for 4 h in aqueous media. The results also revealed that the as-prepared spinel cobalt ferrite nanoparticles have an estimated optical band gap energy in the range of ca. 1.6-1.9 eV, indicating the semiconducting characteristics of the products.

4.
Int J Biol Macromol ; 154: 621-633, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32179117

RESUMO

Drug delivery systems with controlled release have been considered important tools for the treatment of various diseases. The efficacy of the drug can be enhanced by increasing its solubility, stability, bioavailability, and specific site delivery. Herein, we investigated cisplatin (cisP) loading efficacy and release potentiality on chitosan (CS) functionalized with magnetite (M), silicon dioxide (S), and graphene oxide (GO) nanoparticles. Different nanocomposites [chitosan-coated magnetite, silicon dioxide, and graphene oxide (CS/M/S/GO); chitosan-coated magnetite and silicon dioxide (CS/M/S); chitosan-coated silicon dioxide (CS/S); and chitosan-coated magnetite (CS/M)] were prepared. The prepared nanocomposites were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), scanning electron microscopy, transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS). DFT calculations were employed to explore the interaction mechanism of cisP with a selected chitosan-functionalized nanocomposite in the gas phase and water media. The UV-Vis spectroscopy was used to study cisP loading and release from the prepared nanocomposites. The results showed that the highest loading efficacy was achieved by CS/M and CS/M/S/GO nanocomposites (87% and 84% respectively). While the releasing potentiality for CS/M composite was the highest compared with the other ones (91%).


Assuntos
Quitosana/química , Portadores de Fármacos/química , Óxido Ferroso-Férrico/química , Grafite/química , Nanocompostos/química , Dióxido de Silício/química , Cisplatino/metabolismo , Liberação Controlada de Fármacos
5.
RSC Adv ; 10(43): 25567-25585, 2020 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-35518600

RESUMO

We herein have developed a mild approach for the fabrication of glauconite clay (G)-modified chitosan (CS) nanocomposites by the combination of a simple blending and crosslinking method. The chitosan was modified with ethylenediaminetetraacetic acid (EDTA), glutaraldehyde (GL), sodium dodecyl sulfate (SDS), and cetyltrimethyl ammonium bromide (CTAB). The as-prepared composites were identified using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), nitrogen physical adsorption (BET), atomic absorption spectrophotometry (AA), and thermal gravimetric analysis (TGA). The adsorption activities of the as-prepared materials were assessed for the removal of fluoride ions from aqueous media using a batch technique. Raw glauconite (G), GL-CS/G, SDS-CS/G, EDTA-GL-CS/G, and CTAB-CS/G adsorbents displayed maximum adsorption capacity values of 1.15, 4.31, 4.55, 6.90, and 9.03 mg g-1, respectively. The adsorption results were well described by employing the pseudo-second-order kinetic and Langmuir isotherm models. The estimated thermodynamic constants indicated that the F- ion adsorption was a spontaneous, physisorption process. Furthermore, the modified chitosan adsorbents are good candidates for the adsorptive elimination of F- ions from aqueous solutions, according to their reusability, high stability, good adsorption capacity, and applicability for actual field water samples.

6.
Spectrochim Acta A Mol Biomol Spectrosc ; 131: 329-34, 2014 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-24835935

RESUMO

In this paper a novel and inexpensive route for the preparation of spinel magnesium aluminate nanoparticles (MgAl2O4) is proposed. Magnesium aluminate photocatalyst was synthesized via sol-gel auto combustion method using oxalic acid, urea, and citric acid fuels at 350°C. Subsequently, the burnt samples were calcined at different temperatures. The pure spinel MgAl2O4 with average crystallite size 27.7, 14.6 and 15.65nm was obtained at 800°C calcinations using the aforementioned fuels, respectively. The obtained samples were characterized by powder X-ray diffraction, Fourier transform infrared, UV-Vis spectroscopy, transmission electron microscope, scanning electron microscope. The photo catalytic activity of MgAl2O4 product was studied by performing the decomposition of Reactive Red Me 4BL dye under UV illumination or sunlight irradiation. The dye considerably photocatalytically degraded by 90.0% and 95.45% under UV and sunlight irradiation, respectively, within ca. 5h with pseudo first order rate constants of 5.85×10(-3) and 8.38×10(-3)min(-1), respectively.


Assuntos
Compostos de Alumínio/química , Compostos de Magnésio/química , Nanopartículas/química , Compostos de Alumínio/síntese química , Catálise , Corantes/química , Compostos de Magnésio/síntese química , Nanopartículas/ultraestrutura , Transição de Fase , Fotólise , Luz Solar , Raios Ultravioleta
7.
Dalton Trans ; 43(4): 1509-18, 2014 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-24285119

RESUMO

We herein report the preparation of several mononuclear-metaphosphate complexes using simple techniques and mild conditions with yields ranging from 56% to 78%. Treatment of cyclo-tetrametaphosphate ([TBA]4[P4O12]·5H2O, TBA = tetra-n-butylammonium) with various metal sources including (CH3CN)3Mo(CO)3, (CH3CN)2Mo(CO)2(η(3)-C3H5)Cl, MoO2Cl2(OSMe2)2, and VOF3, leads to the clean and rapid formation of [TBA]4[(P4O12)Mo(CO)3]·2H2O, [TBA]3[(P4O12)Mo(CO)2(η(3)-C3H5)], [TBA]3[(P4O12)MoO2Cl] and [TBA]3[(P4O12)VOF2]·Et2O salts in isolated yields of 69, 56, 68, and 56% respectively. NMR spectroscopy, NMR simulations and single crystal X-ray studies reveal that the [P4O12](4-) anion behaves as a tridentate ligand wherein one of the metaphosphate groups is not directly bound to the metal. cyclo-Trimetaphosphate-metal complexes were prepared using a similar procedure i.e., treatment of [PPN]3[P3O9]·H2O (PPN = bis(triphenylphosphine)iminium) with the metal sources (CH3CN)2Mo(CO)2(η(3)-C3H5)Cl, MoO2Cl2(OSMe2)2, MoOCl3, VOF3, WOCl4, and WO2Cl2(CH3CN)2 to produce the corresponding salts, [PPN]2[(P3O9)Mo(CO)2(η(3)-C3H5)], [PPN]2[(P3O9)MoO2Cl], [PPN]2[(P3O9)MoOCl2], [PPN]2[(P3O9)VOF2]·2CH2Cl2, and [PPN]2[(P3O9)WO2Cl] in isolated yields of 78, 56, 75, 59, and 77% respectively. NMR spectroscopy, NMR simulations and single-crystal X-ray studies indicate that the trianionic ligand [P3O9](3-) in these complexes also has κ(3) connectivity.


Assuntos
Metais/química , Fosfatos/química , Ciclização , Espectroscopia de Ressonância Magnética
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