Shaping of Bulk Glasses and Ceramics with Nanosized Particles

2008 ◽  
pp. 389-396
Author(s):  
Jan Tabellion ◽  
Rolf Clasen
Keyword(s):  
Nanosized Particles ◽  
Bulk Glasses

Review on Methodologies Used in the Synthesis of Metal Nanoparticles: Significance of Phytosynthesis Using Plant Extract as an Emerging Tool

2020 ◽  
Vol 26 (40) ◽  
pp. 5188-5204
Author(s):  
Uzair Nagra ◽  
Maryam Shabbir ◽  
Muhammad Zaman ◽  
Asif Mahmood ◽  
Kashif Barkat
Keyword(s):  
Green Synthesis ◽  
Metal Nanoparticles ◽  
Plant Extracts ◽  
Biomedical Applications ◽  
Noble Metals ◽  
Cost Effective ◽  
Green Technology ◽  
Critical Parameters ◽  
Nanosized Particles ◽  
Preparation Methods

Nanosized particles, with a size of less than 100 nm, have a wide variety of applications in various fields of nanotechnology and biotechnology, especially in the pharmaceutical industry. Metal nanoparticles [MNPs] have been synthesized by different chemical and physical procedures. Still, the biological approach or green synthesis [phytosynthesis] is considered as a preferred method due to eco-friendliness, nontoxicity, and cost-effective production. Various plants and plant extracts have been used for the green synthesis of MNPs, including biofabrication of noble metals, metal oxides, and bimetallic combinations. Biomolecules and metabolites present in plant extracts cause the reduction of metal ions into nanosized particles by one-step preparation methods. MNPs have remarkable attractiveness in biomedical applications for their use as potential antioxidant, anticancer and antibacterial agents. The present review offers a comprehensive aspect of MNPs production via top-to-bottom and bottom-to-top approach with considerable emphasis on green technology and their possible biomedical applications. The critical parameters governing the MNPs formation by plant-based synthesis are also highlighted in this review.

Composite cladded powders for spraying of protective coatings

2019 ◽  
pp. 59-64
Author(s):  
E. Yu. Gerashchenkova ◽  
T. I. Bobkova ◽  
E. A. Samodelkin ◽  
B. V. Farmakovsky
Keyword(s):  
Tungsten Carbide ◽  
Gas Phase ◽  
High Speed ◽  
Protective Coatings ◽  
Powder Materials ◽  
Nanosized Particles

The paper presents results of the development of technology for producing cladded and surfacealloyed powder materials. High-speed mechanosynthesis of matrix powders of FeCrAl and solid nanosized particles of tungsten carbide occurs in a disintegrator in the presence of an active gas phase (nitrogen).

scholarly journals Periodicity and Atomic Ordering in Nanosized Particles of Crystals

2008 ◽  
Vol 112 (24) ◽  
pp. 8907-8911 ◽  
Author(s):  
Valeri Petkov ◽  
Nick Bedford ◽  
Marc R. Knecht ◽  
Michael G. Weir ◽  
Richard M. Crooks ◽  
...  
Keyword(s):  
Nanosized Particles ◽  
Atomic Ordering

LASER-DRIVEN SYNTHESIS OF CARBON AND SILICON CLUSTERS FROM GAS-PHASE REACTANTS

1996 ◽  
Vol 03 (01) ◽  
pp. 807-811 ◽  
Author(s):  
M. EHBRECHT ◽  
H. FERKEL ◽  
V.V. SMIRNOV ◽  
O. STELMAKH ◽  
W. ZHANG ◽  
...  
Keyword(s):  
Gas Phase ◽  
Flow Reactor ◽  
Carbon Clusters ◽  
Molecular Flow ◽  
Silicon Cluster ◽  
Nanosized Particles ◽  
Silicon Clusters ◽  
Molecular Gases ◽  
Induced Decomposition ◽  
Cluster Beams

A newly developed technique is employed for the production of carbon and silicon cluster beams starting from gaseous compounds. It is based on the CO 2-laser-induced decomposition of molecular gases containing carbon and silicon, such as CO 2H2 and SiH 4, in a flow reactor. In order to decompose acetylene, SF 6 is used as a sensitizer. By introducing a skimmer into the reaction zone, the generated silicon and carbon clusters are transferred to free molecular flow and analyzed with a time-of-flight mass spectrometer. It is shown that the technique can be efficiently employed to produce fullerenes C 60 and C 70 and, in the case of silicon, ultrapure nanosized particles of up to 3-nm diameter.

Effect of the Dispersion of Nanosized Carbides (NbC - TaC) in the Sintered Microstructure of the Stainless Steel 316L

2008 ◽  
Vol 591-593 ◽  
pp. 294-298
Author(s):  
Uilame Umbelino Gomes ◽  
L.A. Oliveira ◽  
S.R.S. Soares ◽  
M. Furukava ◽  
C.P. Souza
Keyword(s):  
Stainless Steel ◽  
Automotive Industry ◽  
Sintering Temperature ◽  
Vacuum Furnace ◽  
Nanosized Particles ◽  
Stainless Steel 316L ◽  
Wide Range ◽  
Sintered Stainless Steel ◽  
20 Nm ◽  
Hardness Values

Sintered stainless steel has a wide range of applications mainly in the automotive industry. Properties such as wear resistance, density and hardness can be improved by addition of nanosized particles of refractory carbides. The present study compares the behavior of the sintering and hardness of stainless steel samples reinforced with NbC or TaC (particles size less than 20 nm) synthesized at UFRN. The main aim of this work was to identify the effect of the particle size and dispersion of different refractory carbides in the hardness and sintered microstructure. The samples were sintered in a vacuum furnace. The heating rate, sintering temperature and times were 20°C/min, 1290°C and 30, 60 min respectively. We have been able to produce compacts with a relative density among 95.0%. The hardness values obtained were 140 HV for the reinforced sample and 76 HV for the sample without reinforcement.

Nanotechnology: The Challenge of Regulating Known Unknowns

2006 ◽  
Vol 34 (4) ◽  
pp. 704-713 ◽  
Author(s):  
Robin Fretwell Wilson
Keyword(s):  
Occupational Health ◽  
Pulmonary Edema ◽  
Nanosized Particles ◽  
Washington Post ◽  
Respiratory Problems ◽  
Known Unknowns

Nanotechnology is a subject about which we know less than we should, but probably more than we think we do at first glance. Like Defense Secretary Donald Rumsfeld's “known unknowns,” we have learned enough to know what we should be concerned with. Glimmers of risk cropped up recently when German authorities recalled a bathroom cleansing product, “MagicNano,” that purported to contain nanosized particles (NSPs) and was on the market for only three days. More than one hundred people suffered severe respiratory problems – six of whom were hospitalized with pulmonary edema. Although a subsequent analysis of MagicNano found that the nanoliquid ingredient morphed in the production into “supersized” (not nanosized) particles, the recall nonetheless turned a white hot spotlight on the risk of NSPs. Latching onto the risks posed to workers producing materials using nanotechnology, the Washington Post has labeled nanotechnology a “seat-of-thepants occupational health experiment.”

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