A facile green approach for synthesizing monodisperse magnetite nanoparticles

2010 ◽  
Vol 25 (5) ◽  
pp. 810-813 ◽  
Author(s):  
Ling Li ◽  
Jun Ding ◽  
Junmin Xue
Keyword(s):  
Oleic Acid ◽  
Magnetite Nanoparticles ◽  
Synthetic Methods ◽  
Capping Agent ◽  
High Quality ◽  
Green Approach ◽  
Surfactant Complex ◽  
Acid Ratio ◽  
Size And Morphology ◽  
Controllable Size

The synthesis of monodisperse magnetite nanoparticles (Fe3O4 NPs) has been widely investigated over the last decade. Among the various synthetic methods, thermal decomposition of iron acetylacetonate, Fe(acac)3, or the premade iron-surfactant complex, was demonstrated to be promising to obtain monodisperse Fe3O4 NPs with controllable size and morphology. However, toxic and expensive precursors or tedious experimental procedures are normally required in these approaches. In this communication, we report a facile chemical top-down method to synthesize monodisperse magnetite NPs by using rust, which is mainly composed of γ-Fe2O3, as the iron source and oleic acid as the capping agent. The particle size, and hence the magnetization, of NPs can be readily controlled by adjusting the rust/oleic acid ratio and reaction temperature. This process is a green chemical approach and is easy to be reproduced and scaled up, which could be developed as an effective way to convert waste materials into high quality nanocrystals.

Transition-Metal-Free Synthetic Strategies for the Cross-Coupling Reactions in Water: A Green Approach

2020 ◽  
Vol 07 ◽  
Author(s):  
Tanmay Chatterjee ◽  
Nilanjana Mukherjee
Keyword(s):  
Transition Metal ◽  
Organic Solvents ◽  
Aqueous Media ◽  
Cross Coupling ◽  
Transition Metal Catalysts ◽  
Synthetic Methods ◽  
Coupling Reactions ◽  
Organic Transformations ◽  
Green Approach ◽  
Dehydrogenative Coupling

Abstract: A natural driving force is always working behind the synthetic organic chemists towards the development of ‘green’ synthetic methodologies for the synthesis of useful classes of organic molecules having potential applications. The majority of the essential classes of organic transformations, including C-C and C-X (X = heteroatom) bond-forming crosscoupling reactions, cross dehydrogenative-coupling (CDC) mostly rely on the requirement of transition-metal catalysts and hazardous organic solvents. Hence, the scope in developing green synthetic strategies by avoiding the use of transitionmetal catalysts and hazardous organic solvents for those important and useful classes of organic transformations is very high. Hence, several attempts are made so far. Water being the most abundant, cheap, and green solvent in the world; numerous synthetic methods have been developed in an aqueous medium. In this review, the development of transitionmetal- free green synthetic strategies for various important classes of organic transformations such as C-C and C-X bondforming cross-coupling, cross dehydrogenative-coupling, and oxidative-coupling in an aqueous media is discussed.

scholarly journals Low-temperature and ammonia-free epitaxy of GaN/AlGaN/GaN heterostructure

2021 ◽  
Author(s):  
David Maria Tobaldi ◽  
Valentina Triminì ◽  
Arianna Cretì ◽  
Mauro Lomascolo ◽  
Stefano Dicorato ◽  
...  
Keyword(s):  
Growth Temperature ◽  
Chemical Vapour ◽  
High Growth ◽  
Wide Band ◽  
Cost Effective ◽  
Organic Chemical ◽  
High Electron ◽  
High Quality ◽  
Lower Growth ◽  
Green Approach

Wide band gap semiconductors are very attractive because of their broad applications as electronics and optoelectronics materials − GaN-based materials being by far the most promising. For the production of such nitride-based optical and power devices, metal-organic chemical vapour deposition (MOCVD) is routinely used. However, this has disadvantages, such as the large consumption of ammonia gas, and the need for high growth temperature. To go beyond such a limit, in this study we successfully developed a remote plasma assisted MOCVD (RPA-MOCVD) approach for the epitaxial growth of high-quality GaN/AlGaN heterostructures on 4H-SiC substrates. Our RPA-MOCVD has the advantages of lower growth temperature (750 °C) compared to conventional MOCVD route, and the use of a remote N2/H2 plasma instead of ammonia for nitrides growth, generating in situ the NHx (x = 0−3) species needed for the growth. As assessed by structural, morphological, optical and electrical characterisation, the proposed strategy provides an overall cost-effective and green approach for high-quality GaN/AlGaN heteroepitaxy, suitable for high electron mobility transistors (HEMT) technology.

scholarly journals Probing the stability and magnetic properties of magnetosome chains in freeze-dried magnetotactic bacteria

2020 ◽  
Vol 2 (3) ◽  
pp. 1115-1121
Author(s):  
Philipp Bender ◽  
Lourdes Marcano ◽  
Iñaki Orue ◽  
Diego Alba Venero ◽  
Dirk Honecker ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetite Nanoparticles ◽  
Magnetotactic Bacteria ◽  
Magnetic Compass ◽  
High Quality ◽  
Magnetospirillum Gryphiswaldense ◽  
Freeze Dried ◽  
A Chain ◽  
The Stability

Magnetospirillum gryphiswaldense biosynthesize high quality magnetite nanoparticles, called magnetosomes, and arrange them into a chain that behaves like a magnetic compass.

scholarly journals High Encapsulation Efficiency of Magnetite Nanoparticles in Hydrophobic Polymer Microcapsules using Microsuspension Conventional Radical Polymerization

2019 ◽  
Vol 35 (2) ◽  
pp. 516-522 ◽  
Author(s):  
Jittaya Sadchaiyaphum ◽  
Pongsathon Phapugrangkul ◽  
Preeyporn Chaiyasat ◽  
Amorn Chaiyasat
Keyword(s):  
Aqueous Solution ◽  
Oleic Acid ◽  
Radical Polymerization ◽  
Magnetite Nanoparticles ◽  
Driving Force ◽  
Encapsulation Efficiency ◽  
Polymer Particle ◽  
Polymer Shell ◽  
Hydrophobic Polymer ◽  
Co Precipitation

High encapsulation efficiency of magnetite nanoparticles (MNPs; Fe3O4) in microcapsules using PDVB as a hydrophobic polymer shell was successfully achieved by microsuspension conventional radical polymerization (ms CRP). MNPs were initially synthesized by co-precipitation of Fe2+/Fe3+ in a binary phase. During the nucleation of MNPs in alkaline aqueous solution existing oleic acid (OA), MNPs were coated with OA (MNPs-OA) before moving to the toluene phase with the addition of salt. At OA concentration of 0.3 wt%, most of the nucleated MNPs were hydrophobic and well dispersed in the toluene phase. Using DVB as a monomer for ms CRP, high encapsulation efficiency (92 %EE) of MNPs-OA was obtained, with low free polymer particle formation. By contrast, large amounts of free polymer particles were observed at low %EE (32%) of MNPs. The main driving force for high %EE was obtained by coating the surface of the MNPs by OA which increased hydrophobicity.

Demulsification of Oleic-Acid-Coated Magnetite Nanoparticles for Cyclohexane-in-Water Nanoemulsions

2014 ◽  
Vol 28 (9) ◽  
pp. 6172-6178 ◽  
Author(s):  
Jiling Liang ◽  
Haiping Li ◽  
Jingen Yan ◽  
Wanguo Hou
Keyword(s):  
Oleic Acid ◽  
Magnetite Nanoparticles

Preparation of ultrafine silver powders with controllable size and morphology

2018 ◽  
Vol 28 (3) ◽  
pp. 524-533 ◽  
Author(s):  
Qing-hua TIAN ◽  
Duo DENG ◽  
Yu LI ◽  
Xue-yi GUO
Keyword(s):  
Size And Morphology ◽  
Controllable Size

A facile synthesis to Zn2SiO4:Mn2+ phosphor with controllable size and morphology at low temperature

2007 ◽  
Vol 314 (2) ◽  
pp. 510-513 ◽  
Author(s):  
Tian Jun Lou ◽  
Jing Hui Zeng ◽  
Xiang Dong Lou ◽  
Hai Li Fu ◽  
Ye Feng Wang ◽  
...  
Keyword(s):  
Low Temperature ◽  
Facile Synthesis ◽  
Size And Morphology ◽  
Controllable Size
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