جستجوی مقالات مرتبط با کلیدواژه « metal nanoparticles » در نشریات گروه « شیمی »
تکرار جستجوی کلیدواژه «metal nanoparticles» در نشریات گروه «علوم پایه»-
در کار پژوهشی حاضر، نانوهیبریدهای نانولوله های کربنی چند دیواره-نانوذره های فلزی (M-MWCNT; M = Cu, Mn) به روش کاهش شیمیایی تهیه شدند و نانوهیبریدهای به دست آمده برای اصلاح الکترود خمیر کربن (CPE) واجد 1-بوتیل 3- متیل ایمیدازولیوم هگزا فلیوروفسفات به عنوان مایع یونی (IL) مورد استفاده قرار گرفتند. بدین منظور، MWCNT عامل دار شده و پیش ماده های فلزی با استفاده از هیدرازین مونوهیدرات به طور شیمیایی کاهش یافتند. ریخت شناسی و اندازه ذره ها با استفاده از FE-SEM مورد بررسی قرار گرفتند. مطالعه های FE-SEM، تشکیل نانوذره های Cu و Mn را با اندازه های میانگین به ترتیب حدود 65 و nm 90 بر سطح MWCNT نشان داد. نقشه برداری عنصری از نانوهیبریدهای تهیه شده، پراکندگی به نسبت یکنواخت نانوذره های Cu و Mn را بر سطح MWCNT به نمایش گذاشت. با استفاده از XRD، ساختار بلوری نانوذره های مس و منگنز در نانوهیبریدها شناسایی شد. قابلیت CPEهای واجد IL و نانوهیبریدهای به دست آمده برای اکسایش الکتروکاتالیزی استامینوفن در محلول بافر فسفات M 1/0 (0/7(pH= مورد مطالعه قرار گرفت. نتیجه های به دست آمده نشان دهنده فعالیت الکتروکاتالیزی خوب الکترودهای اصلاح شده نسبت به اکسایش استامینوفن است. همچنین، M-MWCNT/IL/CPE علاوه بر داشتن مساحت سطح بالا، به دلیل اثر هم افزایی، فعالیت الکتروکاتالیزی بالاتری را در برای اکسایش استامینوفن نسبت به سایر الکترودهای به کار گرفته شده در این پژوهش نشان دادند. حدود تشخیص برای Cu-MWCNT/IL/CPE به روش های ولتامتری چرخه ای (CV) و ولتامتری پالس تفاضلی (DPV) به ترتیب 7/6 و µM 35/0 به دست آمدند. همچنین، برای Mn-MWCNT/IL/CPE حدود تشخیص به روش های CV و DPV به ترتیب 6/4 و µM 2/0 محاسبه شدند.
کلید واژگان: نانوهیبرید, نانولوله های کربنی چند دیواره, مایع یونی, نانوذره ها فلزی, استامینوفن}In the present research work, multi-walled carbon nanotubes-metal nanoparticles (M-MWCNT; M = Cu, Mn) nanohybrids were prepared by chemical reduction method and the resulting nanohybrids were used for modification of carbon paste electrode (CPE) including 1-butyl 3-methyl-imidazolium hexafluorophosphate as an ionic liquid (IL). For this purpose, functionalized MWCNT and metallic precursors were chemically reduced by hydrazine monohydrate. Morphology and size of the particles were investigated by FE-SEM. FE-SEM studies showed the formation of Cu and Mn nanoparticles with average sizes of approximately 65 and 90 nm onto MWCNT surface, respectively. Elemental mapping of the prepared nanohybrids demonstrated relatively uniform dispersion of Cu and Mn nanoparticles onto the MWCNT surface. By XRD, the crystalline structure of copper and manganase nanoparticles in nanohybrides was identified. The capability of the CPEs including IL and resulting nanohybrides for electrocatalytic oxidation of acetaminophen was studied in 0.1 M phosphate buffer solution (pH=7.0). The obtained results showed the good electrocatalytic activity of modified electrodes towards acetaminophen oxidation. Also, M-MWCNT/IL/CPE nanohybrid in addition of high surface area, due to the synergistic effect, showed higher electrocatalytic activity towards acetaminophen oxidation that those other electrodes used in this research. Detection limits for Cu-MWCNT/IL/CPE were obtained 6.7 and 0.35 μM by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) methods. Also, for Mn-MWCNT/IL/CPE, detection limits were calculated 4.6 and 0.2 μM by CV and DPVmethods, respectively.
Keywords: Nanohybrid, Multi-walled carbon nanotubes, Ionic liquid, Metal nanoparticles, Acetaminophen} -
Metal nanoparticles (NPs), such as TiO2 NPs, have been extensively researched for their potential use in aquaculture. One of the main uses of TiO2 NPs in aquaculture is as a natural water purifier. TiO2 has photocatalytic properties that make it highly effective in breaking down organic pollutants and toxic substances in water. Additionally, TiO2 NPs have been used to improve the efficiency of aquaculture feed. However, it is important to note that while the use of TiO2 NPs in aquaculture holds promise, there are also some concerns about their safety and environmental impact. Therefore, in this study, we sought to ascertain whether penicillamine and ethylenediaminetetraacetic acid (EDTA), two compounds used in the treatment of heavy metal poisoning and whose efficacy has been demonstrated in both warm-blooded animals and humans, may lessen the toxicity of TiO2 NPs in Nile tilapia. In this study, 280 Nile tilapia fries (3.20±0.12 g) were split into four treatments over the course of three replications. Following that, the OECD Guidelines for the Testing of Chemicals was used to evaluate and compare the acute toxicity of TiO2 NPs. In all stages of toxicity determination, the data demonstrated that the toxicity of TiO2 NPs in the control treatment was significantly higher than that of the treatments given penicillamine and EDTA. Finally, the efficiency of penicillamine is more than that of EDTA, and both of these drugs can be used orally to prevent and treat seafood poisoning caused by TiO2 NPs.Keywords: EDTA, Metal Nanoparticles, TiO2 nanoparticles, toxicity}
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Here we reported the extremely simple one-pot synthesis of silver and gold nanoparticles in a rapid manner. Aqueous leaf extract of the most admired energy plant Jatropha curcas is used as reducing agent here. An alternate and safe energy source, house-hold microwave oven constituted the reaction chamber. Silver and gold nanoparticles were characterized by UV-visible, FT-IR, Powder XRD techniques. Surface plasmon resonance peaks corresponding to silver and gold nanoparticles were 428 nm and 543 nm respectively. The XRD patterns were indexed to reflections originated from (111), (200), (220) and (311) faces of FCC nanosilver and nanogold. Microscopic analysis revealed spherical geometry of silver nanoparticles with an average diameter 20.42±12.2 nm. Gold nanometals exhibited uneven shapes with average size 17.12±2.9 nm. In-vitro antioxidant potential assessment by DPPH model gave IC50 values 19.37±0.63 and 16.59±0.29 µg/ mL for silver and gold nanoparticles. The nanometals showed excellent bactericidal activity in agar well diffusion towards microorganisms namely Bacillus cereus, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Aspergillus nidulans and Aspergillus flavus. Degradation of methylene blue and rhodamine B by NaBH4 happened within 10 minutes in the catalytic presence of silver/gold nanoparticles offered a new means for purification of industrial dye effluents. Hydrogenation of 4-nitrophenol in presence of the prepared nanoparticles validated their catalytic utility. The reaction followed pseudo-first order kinetics with respect to reactant concentration.Keywords: Jatropha curcas, metal nanoparticles, Green synthesis, DPPH, well diffusion, dye degradation}
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International Journal Of Nanoscience and Nanotechnology, Volume:11 Issue: 4, Autumn 2015, PP 281 -288The field of nanobiotechnology mainly encompasses with physics, biology, chemistry and material sciences and it develops novel therapeutic nano-scale materials for biomedical, drug delivery, cancer therapy and pharmaceutical applications. Silver nanoparticles (AgNPs) have unique physiochemical, biological and environmental properties which make them useful in a wide range of applications, so AgNPs was synthesized using mustard plant. The formation and characterization of AgNPs were investigated using UV-visible spectroscopy, Fourier transform infrared spectroscopy (FTIR),X-ray diffraction (XRD) and transmission electron microscopy (TEM). UV-visible spectroscopy showed surface plasmon resonance peak at about 411 nm. FTIR indicated the role of different functional groups (carboxyl, amine, aromatic and hydroxyl) in the formation process of AgNPs. TEM analysis showed spherical particles with size range 1-35 nm and an average size 14 nm. Our measurements showed that mustard seed exudates could mediate facile and eco-friendly biosynthesis of colloidal spherical AgNPs. Also, we studied influence of concentrations of silver nitrate on stability of biosynthesized AgNPs. The results clearly showed that the stability of biosynthesized AgNPs strongly depended on the concentration of used silver ions and increased with increasing the concentration of silver ions in the biosynthesis process. Our results indicated that AgNPs synthesized at higher concentrations of silver nitrate were more stable.Keywords: AgNPs, Eco, friendly, Metal nanoparticles, Synthesis}
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تهیه سبز نانوذره های نقره در دمای محیط با استفاده از روش سونوشیمیایی انجام گرفت که در طی آن از نقره نیترات به عنوان پیش ماده ی نقره، از ژلاتین و آسکوربیک اسید به ترتیب به عنوان پایدارکننده ی نقره و عامل احیا استفاده شد. اثر غلظت پایدارکننده، عامل احیا و زمان قرارگیری در معرض فراصوت در تهیه بررسی شد. بررسی اثر غلظت پایدارکننده و عامل احیا نشان داد که در غلظت های مواد افزودنی مقدارهای بهینه ای وجود دارد که در صورت عبور از این مقدارها یا استفاده کمتر از حد بهینه آن ها، اختلال در فرایند تهیه بروز نموده و اندازه ذره ها و توزیع آن ها را تحت تاثیر خود قرار می دهد. افزون بر آن، زمان قرارگیری در برابر فراصوت نیز در فرایند تهیه بسیار دارای اهمیت بوده و اندازه ذره ها و توزیع آن را متاثر می نماید. با استفاده از مقدارهای بهینه، نانوذره هایی با قطری در بازه ی 5 الی 9 نانومتر به دست آمد. از آزمون اسپکتروفتومتری مرئی فرابنفش به منظور دیدن پیک مشخصه ی نانوذره های نقره استفاده شد و دیدن این پیک در بازه ی 450 – 400 نانومتر، حضور نانوذره های نقره را در محلول نشان داد. از آزمون تفرق دینامیکی نور نیز برای بررسی دقیق و کمی اندازه ذره ها و توزیع آن ها استفاده شد. نتیجه ها نشان داد که در صورت استفاده از مقدارهای بهینه، ذراتی با اندازه های کوچک تر و توزیع باریک تر به دست می آیدکلید واژگان: نانوذره های فلزی, نقره, تهیه سبز, فرایند سونوشیمیایی}Synthesis of silver NanoParticles (NPs) was done in aqueous solution at ambient temperature by the use of ultrasound irradiation. Silver nitrate was used as Ag precursor; gelatin and ascorbic acid were used as eco-friendly capping agent and reducing agent، respectively. Ascorbic acid was added to the 1% wt. aqueous solution of silver nitrate and gelatin slowly. This yellow solution was then sonicated while its color changed continuously to brown، indicating the formation of Ag NPs. The effect of reducing agent and stabilizing material was investigated. UV-Visible test was done for the observation of SPR peak in range of 400-450 nm، which indicates the formation of silver nanoparticles. DLS test was done for better quantitative comparison، and the results showed that the finer particles with narrower distribution can be achieved by using the optimum concentrations. Finally، by using the optimum concentrations and the proper sonication time، the silver nanoparticles were achieved having an average diameter of 7±2 nm.Keywords: Metal nanoparticles, Silver, Green synthesis, Sonochemical process}
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Effects were studied of 200 ppm silver and copper nano-suspensions, with size range from 20 to 80 nm, on the hardness of particleboards produced at an industrial scale at the Iran-Choob Factory, Iran. Metal nano-suspensions were added to the mat at two levels of 100 and 150 milli-liters/kg dry weight wood particles, and the results were compared with those of the control panels. Results showed that the high thermal conductivity coefficient of silver nanoparticles broke down part of the resin bonds; it also heat-treated the surface wood particles, resulting in significant decrease in the hardness of treatment with 150 mL/kg. However, in the nanocopper-treated panels, no significant change was observed due to the lower thermal conductivity coefficient of copper; furthermore, as to the formation of higher hydroxyl bonds, it even slightly increased. High significant correlations were determined between most of the physical and mechanical properties of the panels.Keywords: Composite board, Metal nanoparticles, Heat transferring property, Nanotechnology, Particleboard}
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