Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Int J Biol Macromol ; 273(Pt 2): 133189, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38885856

RESUMO

The elimination of pesticides from polluted water is critical due to their harmful environmental and biological impacts. Recently, there has been interest in utilizing natural polymer-based adsorbents as an eco-friendly approach to eliminate or reduce the levels of water pollutants. In this work, we synthesized an antimicrobial and magnetic bionanocomposite consisting of carboxymethyl gond katira-grafted- poly(3-aminobenzoic acid) with iron oxide and zinc oxide NPs (CMT-g-P3ABA/ZnO/Fe3O4) through an in situ polymerization reaction and examined for its ability to adsorb the pesticide acetamiprid (AP). The bionanocomposite was characterized using several analytical techniques, including spectroscopy; XRD presented the crystalline structure of ZnO/Fe3O4 in the CMT-g-P3ABA amorphous matrix. The ZnO/Fe3O4 partially aggregated formation and exhibited polyhedral crystal shapes was depicted by electron microscopy images, vibrating sample magnetometer (45.06 emu/g), porosimetry (5.52 m2/g), and thermal (Chair yield of approximately 43.83 %) and elemental analyses. Under various conditions, including solution pH (4-9), adsorbent dosage (0.005-0.025 g), time of contact (10-30 min), and pesticide preliminary concentration (200-400 mg/L) in 10 mL of the solution. Based on this research, Adsorption data were perfectly fitted by the Freundlich isotherm model with RAP2= 0.99038, while the pseudo-second-order (PSO) model well-explained adsorption kinetics with RAP2= 0.99847. AP adsorption to the CMT-g-P3ABA/ZnO/Fe3O4 bionanocomposite was successful due to hydrophobic interactions, hydrogen bonding, and π-π stacking. Furthermore, adsorption-desorption experiments demonstrated that the bionanocomposite could be regenerated after three reuse cycles without considerable loss of pesticide removal performance. The bionanocomposite also exhibited promising antimicrobial activity in contradiction to test bacteria.


Assuntos
Antibacterianos , Neonicotinoides , Poluentes Químicos da Água , Purificação da Água , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Purificação da Água/métodos , Antibacterianos/química , Antibacterianos/farmacologia , Neonicotinoides/química , Cinética , Nanocompostos/química , Óxido de Zinco/química
2.
Environ Res ; 252(Pt 2): 118893, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38604485

RESUMO

Pesticides can have harmful impacts on the environment and living organisms. Thus, removing them from polluted water is crucial. In this study, a bionanocomposite of carboxymethyl tragacanth-grafted-poly(3-aminophenol)/zinc oxide@iron oxide (CMT-g-P3AP/ZnO@Fe3O4) synthesized by in situ copolymerization as an efficient adsorbent to eliminate the acetamiprid pesticide from polluted water. The CMT-g-P3AP/ZnO@Fe3O4 magnetic nanocomposite was analyzed utilizing various techniques including FTIR, EDX, FESEM, XRD, BET, CHNSO, and TGA. The results displayed that the resulting nanocomposite with maximum adsorption capacity (Qmax) successfully removed the acetamiprid pesticide from polluted water under optimal conditions such as pH of 7.00, 5.00 mg of adsorbent, 20.0 min duration, and 400 mg/L acetamiprid concentration. According to the linear Langmuir isotherm, the Qmax of the biosorbent was 833 mg/g. The experimental adsorption data fitted well with Temkin's nonlinear isotherm model. The adsorption kinetic data were closely related to the Weber-Morris intraparticle diffusion nonlinear model. After three repetitive cycles, CMT-g-P3AP/ZnO@Fe3O4 can be outstandingly renewed and recycled without significant reduction in its adsorption efficacy, as evidenced by the adsorption-desorption experiments. In addition, the CMT-g-P3AP/ZnO@Fe3O4 displayed the good antibacterial activity against E. coli and S. aureus.


Assuntos
Antibacterianos , Neonicotinoides , Poluentes Químicos da Água , Óxido de Zinco , Poluentes Químicos da Água/química , Óxido de Zinco/química , Adsorção , Antibacterianos/química , Neonicotinoides/química , Tragacanto/química , Nanocompostos/química , Purificação da Água/métodos , Praguicidas/química
3.
Heliyon ; 9(5): e15886, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37206030

RESUMO

A magnetic poly (1,8-diaminonaphthalene)-nickel (PDAN-Ni@Fe3O4) composite as a multifunctional nanocatalyst was prepared in several steps including (I) synthesis of poly (1,8-diaminonaphthalene) (PDAN), (II) modification of PDAN with NiSO4 (PDAN-Ni) and (III) preparation of magnetic nanocatalyst by iron (I and II) salts in the existence of PDAN-Ni complex (PDAN-Ni@Fe3O4). Fourier-transform infrared spectroscopy (FTIR), elemental analysis (CHNSO), vibrating-sample magnetometer (VSM), X-ray diffraction (XRD), energy-dispersive X-ray (EDX), field emission scanning electron microscope (FESEM), ultraviolet-visible (UV-vis), and thermogravimetric analysis (TGA) were applied to characterize the prepared nanocatalyst. The PDAN-Ni@Fe3O4 was applied as an environmentally friendly nanocatalyst for the isoxazole-5(4H)-ones synthesis via a one-pot reaction between aryl/heteroaryl aldehyde, hydroxylamine hydrochloride, and ß-ketoester. The nanocomposite was also used for the synthesis of some new alkylene bridging bis 4-benzylidene-3-methyl isoxazole-5(4H)-ones. The catalyst's reusability, and the antioxidant and antibacterial activities of both catalyst and products, were studied. Results showed that the nanocatalyst and isoxazole-5(4H)-ones have antioxidant activity of 75% and 92%, respectively. In addition, the antibacterial test showed that the nanocatalyst and isoxazole-5(4H)-ones have highly active versus Staphylococcus aureus and Escherichia coli bacteria. The reusability and stability of the nanocatalyst, a medium to higher product yield and conversion, a faster reaction time, and the use of green solvents were a few benefits of this study.

4.
Curr Org Synth ; 19(2): 246-266, 2022 03 03.
Artigo em Inglês | MEDLINE | ID: mdl-34736384

RESUMO

BACKGROUND: The use of polymer-based catalysts has increased because of their high potential application as an effective catalyst in organic reactions. They have benefits such as high efficiency and reactivity, simple separation, and safety compared to other heterogeneous catalysts. AIM AND OBJECTIVE: The objective of the current research is to prepare solid polymer-based catalysts, poly(aniline-co-m-phenylenediamine) (PAmPDA), and its superparamagnetic nanocomposite. Then, the catalytic activity of the resulting superparamagnetic nanocomposite was investigated in the synthesis of 1H-pyrazolo[1,2-b]phetalazine-5,10-diones and 1H-pyrazolo[1,2-a]pyridazine-5,8-dione derivatives. A series of some 1H-pyrazolo[1,2-b]phetalazine-5,10-diones and 1H-pyrazolo[1,2-a]pyridazine-5,8-dione derivatives was tested for its antibacterial properties against the Staphylococcus aureus and E. coli bacteria. MATERIALS AND METHODS: PAmPDA copolymer was synthesized in a 1:2 molar ratio of Ani to mPDA via radical oxidative polymerization at room temperature. Superparamagnetic PAmPDA@Fe3O4nanocompo-site was synthesized from a mixture of Fe(II), Fe(III) solution, and PAmPDA copolymer via the in-situ co-precipitation technique. 1H-pyrazolo[1,2-b]phetalazine-5,10-diones were synthesized via one-pot three-component condensation reaction of Phthalhydrazide, aromatic aldehyde derivatives, and malono-nitrile in the presence of PAmPDA under solvent-free conditions at 80 °C. The synthesis of 1H-pyrazolo[1,2-a]pyridazine-5,8-dione derivatives was carried out via a one-pot three-component condensa-tion reaction of maleic hydrazide, aromatic aldehyde derivatives, and malononitrile in the presence of PAmPDA under reflux conditions at EtOH/H2O 1:1. The antibacterial activity of some derivatives was tested against Gram-positive and Gram-negative bacteria. RESULTS: First, superparamagnetic PAmPDA@Fe3O4 nanocomposite was synthesized and characterized successfully, and then the resulting nanocatalyst was used for the synthesis of pyrazolo[1,2-b]phthalazine and pyrazolo[1,2-a]pyridazine. We obtained the maximum yield of the desired 1H-pyrazolo[1,2-b]phthalazine-5,10 dione derivatives with 0.05 g of catalyst at 80°C, under solvent free conditions, whereby the reaction was complete within 30 min. A wide range of 1H-pyrazolo[1,2-b]phthalazine-5,10 dione derivatives were synthesized in good to excellent yield. On the other hand, pyrazolo[1,2-a]pyridazine derivative was synthesized successfully in high yield using PAmPDA as a nanocatalyst. The antibacterial activity of some derivatives, according to the data (inhibition zone%), showed good ac-tivity against Staphylococcus aureus and E. coli. CONCLUSION: In this research, PAmPDA was used for mild preparation of 1H-pyrazolo [1,2-a]pyridazine-5,8-diones & 1H-pyrazolo[1,2-b]phetalazine-5,10-diones derivatives with excellent yields and short reac-tion times. The attractive features of this protocol are simple procedure, cleaner reaction, and the use of recyclable nanocatalyst. Satisfactory yields of products and easy workup make this a useful protocol for the green synthesis of this class of compounds. The antibacterial activity of some derivatives, according to the data (inhibition zone%), showed good activity against Staphylococcus aureus and E. coli.


Assuntos
Antibacterianos , Nanocompostos , Aldeídos , Compostos de Anilina , Antibacterianos/farmacologia , Escherichia coli , Compostos Férricos , Bactérias Gram-Negativas , Bactérias Gram-Positivas , Nanopartículas Magnéticas de Óxido de Ferro , Fenilenodiaminas , Ftalazinas , Polímeros , Piridazinas , Solventes , Staphylococcus aureus
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...