期刊文献+
共找到4,865篇文章
< 1 2 244 >
每页显示 20 50 100
Synthesis, Characterization and Optical Morphology of ZnO Nanoparticles
1
作者 Aida Smajlagić Almedina Modrić-Šahbazović +1 位作者 Zerina Sakić Elvir Babajić 《Open Journal of Applied Sciences》 2024年第5期1330-1337,共8页
The ZnO molecule plays an important role in the industry due to it special features, anti-corrosion anti-bacterial properties, as well as due to its low electrical conductivity and heat resistance. In these experiment... The ZnO molecule plays an important role in the industry due to it special features, anti-corrosion anti-bacterial properties, as well as due to its low electrical conductivity and heat resistance. In these experimental researches, the sol-gel method was chosen, which enables control of nucleation, aging and growth of particles in the solution. ZnO synthesis was prepared utilizing chemical method with Zinc acetate dyhidrate and NaOH with the appropriate methanol solvent and heating (60˚C). The methods used in identification and characterization are FTIR, UV/VIS, OPTICAL MICROSCOPY, SEM and XRD. The FTIR spectra of synthesized ZnO with corresponding ones show characteristic bands at the corresponding wavelengths, which confirm the presence of ZnO nanoparticles. SEM characterization of ZnO shows the morphology of needle-shaped nanoparticles. XRD spectar in this research by chemical method indicates the particle size of 17.76 nm. 展开更多
关键词 synthesis ZnO nanoparticles Sol-Gel Method FTIR SEM XRD
下载PDF
Green synthesis and characterization of palladium nanoparticles and its conjugates from solanum trilobatum leaf extract 被引量:4
2
作者 Amarnath Kanchana Saveetha Devarajan Senniyanallur Rathakrishnan Ayyappan 《Nano-Micro Letters》 SCIE EI CAS 2010年第3期169-176,共8页
An important area of research in nanotechnology deals with the synthesis of nanoparticles of different chemical compositions,sizes and controlled monodispersity.Currently,there is a growing need to develop environment... An important area of research in nanotechnology deals with the synthesis of nanoparticles of different chemical compositions,sizes and controlled monodispersity.Currently,there is a growing need to develop environmentally benign nanoparticle synthesis in which no toxic chemicals are used in the synthesis protocol.Palladium nanoparticles(Pd Np) are of interest because of their catalytic properties and affinity for hydrogen.Our protocol for the phyto-synthesis of Pd Np under moderate p H and room temperature offers a new means to develop environmentally benign nanoparticles.Solanum trilobatum is enlightened in our present study as it is enriched with phytochemicals to reduce palladium chloride ions.Poly MVA a dietary supplement based on the nontoxic chemotherapeutic lipoic acid-palladium complex(LA-Pd) is been hypothesized as the new paradigm of cancer therapy.Hence forth we successfully conjugated lipoic acid(S-Pd Np-LA) and vitamins(S-Pd Np-Vitamin-LA) to palladium nanoparticles synthesised from Solanum trilobatum leaf extract.These nanoparticles(S-Pd Np,S-Pd Np-LA,S-Pd Np-Vitamin-LA) were characterized with UV-Vis Spectroscopy,SEM and FTIR analysis,which revealed that S-Pd Np are polydisperse and of different morphologies ranging from 60?70 nm(S-Pd Np),65?80 nm(S-Pd Np-LA) and 75?100 nm(S-Pd Np-Vitamin-LA) in size. 展开更多
关键词 nanoparticles PALLADIUM Lipoic acid Palladium lipoic acid complex Poly-MVA Green synthesis Solanum trilobatum
下载PDF
Compiexation-Coprecipitation Synthesis and Characterization of Neodymium and Antimony Doped SnO_2 Conductive Nanoparticles 被引量:2
3
作者 刘小珍 桑文斌 +1 位作者 陈捷 王均其 《Journal of Rare Earths》 SCIE EI CAS CSCD 2006年第z2期42-46,共5页
Nd and Sb doped SnO2 conductive nanoparticles were prepared by the complexation-coprecipitation method with Sn, Sb2O3 and Nd2O3 as the raw materials. Thermal behavior, crystal phase, and structure of the prepared cond... Nd and Sb doped SnO2 conductive nanoparticles were prepared by the complexation-coprecipitation method with Sn, Sb2O3 and Nd2O3 as the raw materials. Thermal behavior, crystal phase, and structure of the prepared conductive nanoparticles were characterized by TG/DSC/DTG, FTIR, XRD and TEM techniques, respectively. The resistivity of the prepared conductive nanoparticles was 0.12Ω·cm. TG/DSC/DTG curves show that the precursors lose weight completely before 750℃. FTIR spectrum shows that the vibration peaks are wide peaks in 731 ~ 617 cm-1, and the Nd and Sb doped SnO2 conductive nanoparticles have intense absorption in 4000 ~ 2000 cm-1. Nd and Sb doped SnOi have a structure of tetragonal rutile, and complex doping is achieved well by complexation-coprecipitation method and is recognized as replacement doping or caulking doping. TME shows that the particles are weakly agglomerated, and the size of the particles calcined at 1000℃ranges about 10 nm to 30 nm. 展开更多
关键词 conductive nanoparticles DOPING chemical synthesis SPECTRA rare earths
下载PDF
Green Synthesis of Silver Nanoparticles Using Aqueous Orange and Lemon Peel Extract and Evaluation of Their Antimicrobial Properties
4
作者 Amra Bratovcic Amna Dautovic 《Advances in Nanoparticles》 CAS 2024年第2期11-28,共18页
Green synthesis of silver nanoparticles (AgNPs) using aqueous extracts of orange and lemon peels, as a reducing agent, and silver nitrate salts as a source of silver ions is a promising field of research due to the ve... Green synthesis of silver nanoparticles (AgNPs) using aqueous extracts of orange and lemon peels, as a reducing agent, and silver nitrate salts as a source of silver ions is a promising field of research due to the versatility of biomedical applications of metal nanoparticles. In this paper, AgNPs were synthetized at different reaction parameters such as the type and concentration of the extracts, metal salt concentration, temperature, speed stirring, and pH. The antibacterial properties of the obtained silver nanoparticles against E. coli, as well as the physical and chemical characteristics of the synthesized silver nanoparticles, were investigated. UV-Vis spectroscopy was used to confirm the formation of AgNPs. In addition to green biogenic synthesis, chemical synthesis of silver nanoparticles was also carried out. The optimal temperature for extraction was 65˚C, while for the synthesis of AgNPs was 35˚C. The synthesis is carried out in an acidic environment (pH = 4.7 orange and pH = 3.8 lemon), neutral (pH = 7) and alkaline (pH = 10), then for different concentrations of silver nitrate solution (0.5 mM - 1 mM), optimal time duration of the reaction was 60 min and optimal stirring speed rotation was 250 rpm on the magnetic stirrer. The physical properties of the synthesized silver nanoparticles (conductivity, density and refractive index) were also studied, and the passage of laser light through the obtained solution and distilled water was compared. Positive inhibitory effect on the growth of new Escherichia coli colonies have shown AgNPs synthesized at a basic pH value and at a 0.1 mM AgNO<sub>3</sub> using orange or lemon peel extract, while for a 0.5 mM AgNO<sub>3 </sub>using lemon peel extract. 展开更多
关键词 Green synthesis Silver nanoparticles Orange and Lemon Peel Extract Antibacterial Activity Escherichia coli
下载PDF
Rapid Green Synthesis of Silver Nanoparticles by Reishi and Their Antibacterial Activity and Mechanisms
5
作者 Akamu J. Ewunkem T’nasia Priester +4 位作者 Desia Williams Bailey Ariyon Ilunga Tshimanga Brittany Justice Dinesh K. Singh 《Journal of Biomaterials and Nanobiotechnology》 2024年第3期51-63,共13页
Nanotechnology is a rapidly growing field in biomedical engineering with references to efficiency, safety, and cost-effective approaches. Herein, the objective of this study was to examine an innovative approach to ra... Nanotechnology is a rapidly growing field in biomedical engineering with references to efficiency, safety, and cost-effective approaches. Herein, the objective of this study was to examine an innovative approach to rapidly synthesis silver nanoparticles from an aqueous extract of medicinal mushroom Ganoderma lucidum (also known as reishi). The structural and dimensional dispersion of the biosynthesized silver nanoparticles from reishi was confirmed by UV-Vis spectrophotometer (UV-Vis) and Scanning Electron Microscopy (SEM) analysis. Additionally, the biosynthesized silver nanoparticles from resihi were used to explore their potential antimicrobial activity against Staphylococcus aureus and Micrococcus luteus and Escherichia coli and Klebsiella pneumoniae. The results from this study revealed that the silver nanoparticles mediated by reishi adopted a spherical shape morphology with sizes, less than 100 nm and revealed strong absorption plasmon band at 440 nm. Furthermore, the biosynthesized silver nanoparticles from reishi exhibited antibacterial activity against the tested S. aureus and M. luteus and E. coli and K. pneumoniae by altering their morphology which signifies their biomedical potential. 展开更多
关键词 NANOTECHNOLOGY REISHI nanoparticles ANTIMICROBIAL Green synthesis
下载PDF
Microwave hydrothermal synthesis and characterization of rare-earth stannate nanoparticles
6
作者 Shuang Huang Hua-lan Xu +1 位作者 Sheng-liang Zhong Lei Wang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2017年第7期794-803,共10页
Rare-earth stannate(Ln_2Sn_2O_7(Ln = Y, La–Lu)) nanocrystals with an average diameter of 50 nm were prepared through a facile microwave hydrothermal method at 200°C within 60 min. The products were well char... Rare-earth stannate(Ln_2Sn_2O_7(Ln = Y, La–Lu)) nanocrystals with an average diameter of 50 nm were prepared through a facile microwave hydrothermal method at 200°C within 60 min. The products were well characterized. The effect of reaction parameters such as temperature, reaction time, p H value, and alkali source on the preparation was investigated. The results revealed that the p H value plays an important role in the formation process of gadolinium stannate(Gd_2Sn_2O_7) nanoparticles. By contrast, the alkali source had no effect on the phase composition or morphology of the final product. Uniform and sphere-like nanoparticles with an average size of approximately 50 nm were obtained at the p H value of 11.5. A possible formation mechanism was briefly proposed. Gd_2Sn_2O_7:Eu^(3+) nanoparticles displayed strong orange-red emission. Magnetic measurements revealed that Gd_2Sn_2O_7 nanoparticles were paramagnetic. The other rare-earth stannate Ln_2Sn_2O_7(Ln = Y, La–Lu) nanocrystals were prepared by similar approaches. 展开更多
关键词 microwave hydrothermal synthesis rare-earth stannate nanoparticles
下载PDF
Biosynthesis of Copper Nanoparticles using an Extract of the root of Asparagus racemosus:Basic Synthesis,Antimicrobial,and Anti-oxidant Potentials
7
作者 Subha Veeramani Kirubanandan Shanmugam 《Journal of Clinical and Nursing Research》 2024年第2期137-148,共12页
Copper nanoparticles(CuNPs)have emerged as a promising alternative due to their unique antimicrobial properties.The synthesis of CuNPs using Asparagus racemosus,commonly known as Shatavari,offers a sustainable and env... Copper nanoparticles(CuNPs)have emerged as a promising alternative due to their unique antimicrobial properties.The synthesis of CuNPs using Asparagus racemosus,commonly known as Shatavari,offers a sustainable and environmentally friendly approach to producing nanomaterials.Moreover,the resulting CuNPs have been found to possess excellent antibacterial,and antioxidant properties,which further expands their potential applications in medicine and environmental remediation.In this article,we discussed the in vitro characterization of the CuNPs.In vitro studies revealed that CuNPs have the potential for biomedical applications and as a base nanomaterial for the construction of drug delivery and targeting vehicles. 展开更多
关键词 Copper nanoparticles Green synthesis Asparagus racemosus Antimicrobial and antioxidant activities
下载PDF
Preparation and characterization of pH-responsive metal-polyphenol structure coated nanoparticles
8
作者 Qile Xia Yan Liang +2 位作者 Ailing Cao Yan Cao Luyun Cai 《Food Science and Human Wellness》 SCIE CSCD 2024年第3期1303-1310,共8页
In this paper,tannic acid(TA)and Fe~(3+)were added to form a layer of metal-polyphenol network structure on the surface of the nanoparticles which were fabricated by zein and carbon quantum dots(CQDs)encapsulating phl... In this paper,tannic acid(TA)and Fe~(3+)were added to form a layer of metal-polyphenol network structure on the surface of the nanoparticles which were fabricated by zein and carbon quantum dots(CQDs)encapsulating phlorotannins(PTN).pH-Responsive nanoparticles were prepared successfully(zein-PTN-CQDs-Fe-~Ⅲ).Further,the formation of composite nanoparticles was confirmed by a series of characterization methods.The zeta-potential and Fourier transform infrared spectroscopy data proved that electrostatic interaction and hydrogen bonding are dominant forces to form nanoparticles.The encapsulation efficiency(EE)revealed that metal-polyphenol network structure could improve the EE of PTN.Thermogravimetric analysis and differential scanning calorimetry experiment indicated the thermal stability of zein-PTN-CQDs-Fe~Ⅲnanoparticles increased because of metal-polyphenol network structure.The pH-responsive nanoparticles greatly increased the release rate of active substances and achieved targeted release. 展开更多
关键词 METAL PHLOROTANNINS nanoparticles PH-RESPONSIVE characterization
下载PDF
Green Synthesis, Characterization and Antibacterial Activity of ZnO Nanoparticles
9
作者 Hrishikesh Upadhyaya Soumitra Shome +3 位作者 Rajdeep Sarma Sujit Tewari Mrinal Kanti Bhattacharya Sanjib Kumar Panda 《American Journal of Plant Sciences》 2018年第6期1279-1291,共13页
In the present study, mehendi extract (Lawsonia inermis) was used for phytosynthesis of ZnO nanoparticles using 0.1 M Zn(NO3)2 as precursor under alkaline condition using NaOH with vigorous stirring for 2 h. ZnO NPs o... In the present study, mehendi extract (Lawsonia inermis) was used for phytosynthesis of ZnO nanoparticles using 0.1 M Zn(NO3)2 as precursor under alkaline condition using NaOH with vigorous stirring for 2 h. ZnO NPs obtained were characterized by UV-Vis spectroscopy, XRD, SEM and TEM that showed change in shape and size. Hexagonal particles were formed due to plant extract relative to the rod shaped particles in absence of plant extract. Further the antibacterial property of ZnO NP synthesized by green method was more effective than those synthesized in absence of plant extract. The antibacterial activity study of both the synthesized ZnO nanoparticles reveals that the nanoparticles synthesized using mehendi extract are more effective than the particle synthesized without mehendi extract. Thus, the use of leaf extract as capping agent would improve the antibacterial property of ZnO nanoparticle. However, bacteriocidal effect of these nanoparticles varies with respect to the organism tested. 展开更多
关键词 ANTIBACTERIAL ACTIVITY Green synthesis ZNO nanoparticles Lawsonia inermis
下载PDF
Nanoparticles Modified Electrodes: Synthesis, Modification, and Characterization—A Review
10
作者 Temitayo O. Falola 《World Journal of Nano Science and Engineering》 CAS 2022年第3期29-62,共34页
Nanoparticles offer unique features such as a larger surface area and enhanced electrochemical performance compared to their contemporary matters. These properties make them suitable to be considered in bridging the l... Nanoparticles offer unique features such as a larger surface area and enhanced electrochemical performance compared to their contemporary matters. These properties make them suitable to be considered in bridging the lacunae associated with the use of bare electrodes in electrochemical sensors. Nanomaterials enhance the redox reversibility on the electrodes’ surfaces, hence, improving the reproducibility, sensitivity, and limit of detection of the electrodes/sensors. Their methods of synthesis (top-to-bottom and bottom-to-to-top) are tailored toward manipulating their sizes, shapes, and preventing their agglomeration. This review paper provides a synopsis on research done in synthesizing nanoparticles, modifying electrodes, and pinpointing the improved performances of the modified electrodes via known characteristic techniques, namely: cyclic voltammetry, differential pulse voltammetry, and electrochemical impedance spectroscopy. In addition, a perspective is given in terms of increasing the lifespan of the working electrodes and the need for non-faradaic sensors. 展开更多
关键词 nanoparticles Turkevich Method MODIFICATION characterization Limit of Detection Redox Reversibility Electrochemical Properties
下载PDF
Synthesis and Characterization of KFeP_(2)O_(7) Nanoparticles Implanted in Silica
11
作者 Eduardo Ordónez Regil Enrique Ordónez Regil +1 位作者 Nidia García González Samuel R.Barocio 《American Journal of Analytical Chemistry》 2012年第8期512-517,共6页
Rivers and aquifers are increasingly affected worldwide by the action of agro-industrial pollution. Facing this challenge, nanoparticles have found a wide range of applications in the decontamination and remediation o... Rivers and aquifers are increasingly affected worldwide by the action of agro-industrial pollution. Facing this challenge, nanoparticles have found a wide range of applications in the decontamination and remediation of water, given the characteristics which make them highly reactive to specific substances. One of the simplest ways of gaining access to these particles is through their synthesis over a sufficiently rigid matrix of manageable size. This report describes the synthesis and characterization of nanoparticles of iron and potassium diphosphate (KFeP2O7) synthesized on silica gel beads (SiO2). Analysis by X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) have been applied in order to determine the mineral phases and morphology of the synthesized compounds. Complementary tests were conducted so as to determine surface characteristics such as specific area by the BET method and point of zero charge (pHpzc) by mass titration. The acid-base titration enabled to determine the adsorptive nature of nanoparticles and their response to a pH range from 1 to 12. 展开更多
关键词 KFeP_(2)O_(7) synthesis nanoparticles XRD and XPS Analysis KFeP_(2)O_(7) nanoparticles Implanted in Silica
下载PDF
Green Hydrothermal Synthesis and Applications of Sorbus pohuashanensis/Aronia melanocarpa Extracts Functionalized-Au/Ag/AuAg Nanoparticles
12
作者 Jin Huang Jixiang Sun +4 位作者 Kai Shao Yamei Lin Zhiguo Liu Yujie Fu Liqiang Mu 《Journal of Renewable Materials》 SCIE EI 2023年第4期1807-1821,共15页
Nanoparticles(NPs)have already been widely used in catalysis,antibacterial and coating fields.Compared with the traditional toxic and harmful reducing reagents,green synthesis of NPs by using plant extracts is not onl... Nanoparticles(NPs)have already been widely used in catalysis,antibacterial and coating fields.Compared with the traditional toxic and harmful reducing reagents,green synthesis of NPs by using plant extracts is not only environmental-friendly and cost-effective but also conducive to the multi-level and efficient utilization of wild plant resources.In this study,the aqueous extracts from Sorbus pohuashanensis(SP)and Aronia melanocarpa(AM)fruits were used as the reducing and protective reagents for synthesizing Au/AgNPs,with the characteristics of originality operation and high repeatability.The SP/AM fruit extracts functionalized Au/AgNPs were characterized by UV-vis spectroscopy(UV-vis),transmission electron microscopy(TEM),energy dispersive spectroscopy(EDS),scanning electron microscope(SEM),X-ray diffraction(XRD)and Fourier transform infrared spectroscopy(FTIR).UV-vis spectrums showed the NPs peaks verified by the presence between 400–550 nm;TEM and SEM demonstrated NPs displayed approximately spherical structures;EDS confirmed the existence of Au/Ag elements;XRD measurements confirmed that the obtained NPs showed highly crystalline structures;FTIR demonstrated the fruits extracts were adsorbed on the surface of NPs.Primary experiments indicated that SP/AM fruit extracts functionalized-NPs could be used as the reagents for removing the organic dyes efficiently;Zone of inhibition tests(ZOI)explained that NPs have slow-release antibacterial activity. 展开更多
关键词 Green synthesis nanoparticles Sorbus pohuashanensis Aronia melanocarpa plant extracts dye removal
下载PDF
Green Synthesis of Titanium Oxide Nanoparticles Using Natural Extracts
13
作者 Maribel Santiago Daniela Rivera Agustín Torres 《Journal of Materials Science and Chemical Engineering》 CAS 2023年第2期29-40,共12页
Green synthesis is an alternative method for obtaining nanoparticles for environmentally friendly purposes. The present work describes the synthesis and characterization of titanium oxide nanoparticles, starting from ... Green synthesis is an alternative method for obtaining nanoparticles for environmentally friendly purposes. The present work describes the synthesis and characterization of titanium oxide nanoparticles, starting from three natural sources: orange peel, hibiscus rosa sinensis and Aloe vera. Titanium (IV) tetrabutoxide in ethanol solution was used as precursor. The methodology used was based on the sol-gel technique, through which TiO<sub>2</sub> nanoparticles were obtained in the anatase phase. The characterization of the nanoparticles was carried out by means of x-ray diffraction (XRD), scanning electron microscopy (SEM) and infrared spectrophotometry (FTIR), which allowed the identification of a good degree of purity and crystallinity of the samples obtained. 展开更多
关键词 TiO2 nanoparticles Green synthesis Sol-Gel Methodology Natural Sources
下载PDF
Green Synthesis and Antibacterial Properties of Silver Nanoparticles from Eugenia uniflora Fruit Extract
14
作者 Melissa Moya Vanessa Bagnarello +1 位作者 Julio Mora Idalia Valerio 《Advances in Nanoparticles》 2023年第3期94-105,共12页
The synthesis of nanoparticles by biological methods using microorganisms, enzymes, or plant extracts has been suggested as a possible ecofriendly alternative to chemical and physical methods that involve the use of h... The synthesis of nanoparticles by biological methods using microorganisms, enzymes, or plant extracts has been suggested as a possible ecofriendly alternative to chemical and physical methods that involve the use of harmful reducing agents. Green synthesis of silver nanoparticles (AgNPs) was achieved using Eugenia uniflora ripe fruit extract, which was characterized by phytochemical screening revealing the presence of polyphenols (quinones, flavonoids, and tannins), reducing compounds, and terpenes. These excellent antioxidants reduced silver nitrate to give the AgNPs, which were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), and ζ potential analysis. The diameter of the AgNPs ranged from 10.56 ± 1.2 nm to 107.56 ± 5.7 nm. The antibacterial activity of the AgNPs was evaluated using a modification of the Kirby-Bauer technique with Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. The inhibition halos were 11.12 ± 0.02 mm, 13.96 ± 0.07 mm, and 11.29 ± 0.76 mm, respectively. The synthesis using E. uniflora is an ecofriendly and low cost method of obtaining silver nanoparticles that could be used in health sciences because of their activity against bacteria with antibiotic resistance. 展开更多
关键词 Eugenia uniflora Green synthesis Silver nanoparticles Antibacterial Activity POLYPHENOLS
下载PDF
Synthesis and Characterization of Carboxyl-terminated Polyethylene Glycol Functionalized Mesoporous Silica Nanoparticles 被引量:3
15
作者 WANG Yu LIU Mingxing 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2018年第6期1540-1545,共6页
Colloidal mesoporous silica nanoparticles functionalized with carboxy-terminated polyethylene glycol(CMS-PEG-COOH) were successfully synthesized by covalently grafting dicarboxy-terminated polyethylene glycol(HOOC-PEG... Colloidal mesoporous silica nanoparticles functionalized with carboxy-terminated polyethylene glycol(CMS-PEG-COOH) were successfully synthesized by covalently grafting dicarboxy-terminated polyethylene glycol(HOOC-PEG-COOH) on the surface of the amino functionalized CMS nanoparticles with amide bond as a cross linker. Moreover, the structural and particle properties of CMS-PEG-COOH were characterized by nuclear magnetic resonance spectroscopy(1 H-NMR), transmission electron microscopy(TEM), dynamic light scattering(DLS), nitrogen adsorption-desorption measurements, X-ray diffraction(XRD), and Fourier transform infrared spectroscopy(FT-IR). The nanomaterials presented a relatively uniform spherical shape morphology with diameters of about 120 nm,and favorable dispersibility in weak acid solution. The CMSPEG-COOH exhibited no changes in the state of amorphous, while the mesopores sizes of 5.25 nm might provide the nanomaterials with large capacity for the loading and releasing of drugs. So the results indicated that CMSPEG-COOH might be a critical nanomaterial for drug delivery system in the future. 展开更多
关键词 mesoporous silica nanoparticles polyethylene glycol FUNCTIONALIZATION carboxy-terminated synthesis
下载PDF
Single Step Microwave Assisted Synthesis and Antimicrobial Activity of Silver, Copper and Silver-Copper Nanoparticles
16
作者 Myrna Reyes-Blas Nadja M. Maldonado-Luna +3 位作者 Carla M. Rivera-Quiñones Ana L. Vega-Avila Felix R. Roman-Velázquez Oscar J. Perales-Perez 《Journal of Materials Science and Chemical Engineering》 2020年第8期13-29,共17页
Copper and silver nanoparticles were synthesized and characterized in two minutes at 175<span style="white-space:nowrap;">&#176;</span>C in a one-step synthesis using a modified polyol (ethyl... Copper and silver nanoparticles were synthesized and characterized in two minutes at 175<span style="white-space:nowrap;">&#176;</span>C in a one-step synthesis using a modified polyol (ethylene glycol) method and a microwave heating process. We successfully synthesized spherical Silver (Ag) and Copper nanoparticles (CuNP) with a crystallite size of less than 10 nm, as well as irregular silver-copper nanoparticles (AgCuNP) with a crystallite size of less than 15 nm, as confirmed by X-Ray Diffraction (XRD) and High-Resolution Transmission Electron Microscopy (HRTEM). The successful synthesis of AgCuNP with 1:1 molar ratio and constituted by 51.74% of copper and 48.26% of silver was corroborated using the Energy Dispersive X-ray (EDX) mapping technique. The AgNP and AgCuNP exhibited more stability in suspension, in comparison to CuNP, as observed by continuously monitoring the absorbance with UV-Vis spectroscopy for 12 days. Furthermore, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of AgNP, CuNP, and AgCuNP were determined, against Gram-negative and Gram-positive bacteria, and yeast. The obtained MIC and MBC values indicate that AgCu nanoparticles exhibited bactericidal properties greater than its constituents. On the contrary, antifungal activity of AgCuNP against yeast was not observed. 展开更多
关键词 Ag nanoparticles Cu nanoparticles Microwave synthesis Modified Polyol Method Antimicrobial Properties AgCu nanoparticles
下载PDF
Synthesis and Characterization of Carbon Conditioned with Iron Nanoparticles Using Pineapple-Peel 被引量:1
17
作者 G. García-Rosales L. C. Longoria-Gándara +1 位作者 S. Martínez-Gallegos J. González-Juárez 《Advances in Nanoparticles》 2013年第4期384-390,共7页
This paper presents the preparation of carbon conditioned with iron nanoparticles (CI) using a pineapple peel treated with iron salts, carboxymethylcellulose sodium and hexamine. First, the pineapple peel was analyzed... This paper presents the preparation of carbon conditioned with iron nanoparticles (CI) using a pineapple peel treated with iron salts, carboxymethylcellulose sodium and hexamine. First, the pineapple peel was analyzed by thermo gravimetric analysis (TGA) to determine the optimal temperature for pyrolysis. The formation of carbon conditioned by iron nanoparticles was studied as a function of time at 30 min, 60 min, 90 min, 120 min, 150 min and 180 min. Scanning electron microscopy (SEM) was used to identify changes in the morphology of the materials. The specific area of each material was obtained by the BET method. The elemental composition of pineapple-peel (PP), washed pineapple-peel (WPP) and carbon iron (CI), was determined by neutron activation analysis (NAA). The results show that the optimal time for obtaining spherical iron nanoparticles with a diameter between 10 nm and 30 nm is 180 min on the carbonaceous material with a specific surface area of 167 m2/g. 展开更多
关键词 PINEAPPLE CARBON Iron-nanoparticles synthesis NEUTRON ACTIVATION Analysis
下载PDF
Synthesis and characterization of Fe_3O_4 magnetic nanoparticles and their heating effects under radiofrequency capacitive field
18
作者 李旭红 冯志明 +3 位作者 欧阳伟炜 谢小雪 廖遇平 唐劲天 《Journal of Central South University》 SCIE EI CAS 2010年第6期1185-1189,共5页
Fe3O4 magnetic nanoparticles with diameters varying from 10 to 426 nm were synthesized and characterized.Heating effects of Fe3O4 magnetic nanoparticles under radiofrequency capacitive field(RCF) with frequency of 27.... Fe3O4 magnetic nanoparticles with diameters varying from 10 to 426 nm were synthesized and characterized.Heating effects of Fe3O4 magnetic nanoparticles under radiofrequency capacitive field(RCF) with frequency of 27.12 MHz and power of 60-150 W were investigated.When the power of RCF is lower than 90 W,temperatures of Fe3O4 magnetic nanoparticles(75-150 mg/mL) can be raised and maximal temperatures are all lower than 50 ℃.When the power of RCF is 90-150 W,temperatures of Fe3O4 magnetic nanoparticles can be quickly raised and are all obviously higher than those of normal saline and distilled water under the same conditions.Temperature of Fe3O4 magnetic nanoparticles can even reach 70.2 ℃ under 150 W RCF.Heating effects of Fe3O4 magnetic nanoparticles are related to RCF power,particle size and particle concentration. 展开更多
关键词 Fe3O4 magnetic nanoparticles radiofrequency capacitive field synthesis characterization heating effects
下载PDF
Synthesis of Silver Nanoparticles from Honeybees and Its Antibacterial Potential
19
作者 Akamu J. Ewunkem Niore’s Johnson +3 位作者 A’lyiha F. Beard Ilunga Tshimanga Brittany Justice Jeffery Meixner 《Open Journal of Medical Microbiology》 2024年第1期77-92,共16页
Honeybees (Apis mellifera) are important pollinators of flowering plants and agricultural crops contributing annually to billions of dollars in revenues to crop production. Honeybees have an average lifespan between 8... Honeybees (Apis mellifera) are important pollinators of flowering plants and agricultural crops contributing annually to billions of dollars in revenues to crop production. Honeybees have an average lifespan between 8 weeks to 5 years. Dead honeybees are abundantly available in beehives and can be utilized as an alternative source to synthesize nanoparticles. In recent years, biologically synthesized nanoparticles have been preferred over their chemical counterparts. However, honeybee-based-green synthesis of nanoparticles has not been explored yet. Herein, we report the biosynthesis of silver nanoparticles from honeybees and its antibacterial activity. The synthesis of silver nanoparticles was monitored visually through a gradual change in color. Furthermore, the biosynthesized nanoparticles were confirmed and characterized by UV-visible spectroscopy. Scanning Electron Microscope was utilized to analyze the average size and morphologies of the biosynthesized nanoparticles. Subsequently, the antibacterial potential of the biosynthesized silver nanoparticles was tested against selected Gram-positive and Gram-negative bacterial strains. It was found that a distinct color change from yellow to brown in the reaction solution suggested the formation of silver nanoparticles. The biosynthesized nanoparticles exhibited absorption maxima at 430 nm. The SEM analysis confirmed the spherical and cuboidal shape of the biosynthesized silver nanoparticles with a size range between 10 - 40 nm. Furthermore, the biosynthesized silver nanoparticles exhibited strong antimicrobial potential against tested Gram-positive and Gram-negative bacteria strains by aggregating on the cell surface. This study showcases the biomedical and agricultural applications of biosynthesized silver nanoparticles from honeybee wings. . 展开更多
关键词 HONEYBEE BACTERIA Green synthesis nanoparticles ANTIMICROBIAL
下载PDF
Green Method, Optical and Structural Characterization of ZnO Nanoparticles Synthesized Using Leaves Extract of M. oleifera
20
作者 Jose Vulfrano Gonzalez-Fernandez Diego David Pinzon-Moreno +1 位作者 Antony Alexander Neciosup-Puican Maria Veronica Carranza-Oropeza 《Journal of Renewable Materials》 SCIE EI 2022年第3期833-847,共15页
ZnO nanoparticles(ZnO-NP)present innovative optical,electrical,and magnetic properties that depend on spe-cific characteristics,e.g.,size,distribution,and morphology.Thus,these properties are essential to address vari... ZnO nanoparticles(ZnO-NP)present innovative optical,electrical,and magnetic properties that depend on spe-cific characteristics,e.g.,size,distribution,and morphology.Thus,these properties are essential to address various applications in areas such as electronics,medicine,energy,and others.In addition,the performance of this ZnO-NP depends of their preparation which can be done by chemical,physical,and biological methods.Meanwhile,nowadays,the main interest in developing ZnO-NP synthesis through biological methods bases on the decrease of use of toxic chemicals or energy applied to the procedures,making the process more cost-effective and environ-mentally friendly.However,the large-scale production of nanoparticles by green synthesis remains a big challenge due to the complexity of the biological extracts used in chemical reactions.That being the case,the preparation of ZnO-NP using Moringa oleifera extract as an alternative biological agent for capping and reduction in synthesis was evaluated in this work.Then,the results based on the analysis of the optical and structural characterization of the ZnO-NP obtained by employing UV-Vis,DLS,zeta potential,XRD,ATR-FTIR,and FE-SEM indicate mostly the presence of spherical nanosized material with a mean hydrodynamic diameter of 47.2 nm measured by DLS and a mean size diameter of 25 nm observed with FE-SEM technique.Furthermore,in FE-SEM images a homo-geneous dispersion and distribution is observed in the absence of agglutination,agglomeration,or generation of significant lumps of the ZnO-NP.The XRD analysis showed that heat annealing induced the crystallite size favor-ing their monocrystallinity.Those obtained data confirm the synthesis of ZnO-NP and the absence of impurities associated with organic compounds in the annealed samples.Finally,those results and low-cost production pre-sent to the synthesized ZnO-NP by this biological method as a useful material in several applications. 展开更多
关键词 ZnO nanoparticles green chemistry Moringa oleifera extract optical characterization structural characterization
下载PDF
上一页 1 2 244 下一页 到第
使用帮助 返回顶部