scholarly journals The Capping Agent Is the Key: Structural Alterations of Ag NPs during CO2 Electrolysis Probed in a Zero-Gap Gas-Flow Configuration

2021 ◽  
Author(s):  
Menglong Liu ◽  
Ying Kong ◽  
Huifang Hu ◽  
Noémi Kovács ◽  
Changzhe Sun ◽  
...  
Keyword(s):  
Gas Flow ◽  
Capping Agent ◽  
Ag Nps ◽  
Structural Alterations ◽  
Flow Configuration ◽  
Co2 Electrolysis

scholarly journals Catalytic and anti-bacterial properties of biosynthesized silver nanoparticles using native inulin

RSC Advances ◽  
2018 ◽  
Vol 8 (50) ◽  
pp. 28746-28752 ◽  
Author(s):  
Wei Xu ◽  
Kunling Huang ◽  
Weiping Jin ◽  
Denglin Luo ◽  
Huan Liu ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Capping Agent ◽  
Ag Nps ◽  
Incubation Temperatures

Silver nanoparticles (Ag NPs) were green synthesized using native inulin as the reducing and capping agent with varied incubation temperatures, incubation times and Ag+ concentrations.

Practical aspects in the drawing of an optical fiber

1998 ◽  
Vol 13 (2) ◽  
pp. 483-493 ◽  
Author(s):  
S. Roy Choudhury ◽  
Y. Jaluria
Keyword(s):  
Optical Fibers ◽  
Gas Flow ◽  
Surface Force ◽  
Transport Processes ◽  
Operating Conditions ◽  
Force Balance ◽  
Viscous Stress ◽  
Furnace Temperature ◽  
Flow Configuration ◽  
Fiber Radius

The transport processes in the furnace for the continuous drawing of optical fibers have been studied numerically and analytically. Practical circumstances and operating conditions are considered. A peripheral gas flow configuration has been modeled, along with irises at the ends, as employed in practical furnaces. The neck-down profile of the fiber is not chosen, but has been generated on the basis of a surface force balance. The results obtained are validated by comparisons with earlier experimental results. A detailed analysis has been carried out to determine the relative contributions of different forces during the drawing process. Even though the internal viscous stress is shown to be the major contributor to the draw tension, it is found that under certain operating conditions, the force due to gravity is significant, especially at the beginning of the neck-down region. For a peripheral flow configuration, the effect of flow entrance is found to be very important in determining the necking shape. However, the effect of the iris size on the fiber temperature field is found to be negligible. It is found that for a given furnace temperature and fiber radius, there is an upper limit for draw-down speed at which a fiber can be drawn without rupture. Practical ranges of draw speeds and furnace temperature conditions are identified for the process to be feasible.

Core–Shell γ-Fe2O3/SiO2/PCA/Ag-NPs Hybrid Nanomaterials as a New Candidate for Future Cancer Therapy

2014 ◽  
Vol 13 (01) ◽  
pp. 1450008 ◽  
Author(s):  
R. Soleyman ◽  
A. Pourjavadi ◽  
N. Masoud ◽  
A. Varamesh
Keyword(s):  
Silver Nanoparticles ◽  
Cancer Therapy ◽  
Silver Ions ◽  
Core Shell ◽  
Capping Agent ◽  
Hybrid Nanomaterials ◽  
Ag Nps ◽  
Core Nanoparticles ◽  
Size And Structure

In the current study, γ- Fe 2 O 3/ SiO 2/ PCA / Ag -NPs hybrid nanomaterials were successfully synthesized and characterized. At first, prepared γ- Fe 2 O 3 core nanoparticles were modified by SiO 2 layer. Then they were covered by poly citric acid (PCA) via melting esterification method as well. PCA shell acts as an effective linker, and provides vacancies for conveying drugs. Moreover, this shell as an effective capping agent directs synthesis of silver nanoparticles ( Ag -NPs) via in situ photo-reduction of silver ions by sunlight-UV irradiation. This system has several benefits as a suitable cancer therapy nanomaterial. Magnetic nanoparticles (MNPs) can guide Ag -NPs and drugs to cancer cells and then Ag -NPs can affect those cells via Ag -NPs anti-angiogenesis effect. Size and structure of the prepared magnetic hybrid nanomaterials were characterized using FTIR and UV-Vis spectra, AFM and TEM pictures and XRD data.

scholarly journals Green and Sustainable Manufacture of Ultrapure Engineered Nanomaterials

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 466
Author(s):  
David Ortiz de Zárate ◽  
Carlos García-Meca ◽  
Elena Pinilla-Cienfuegos ◽  
José A. Ayúcar ◽  
Amadeu Griol ◽  
...  
Keyword(s):  
Mass Production ◽  
Gas Flow ◽  
Colloidal Stability ◽  
Cost Effective ◽  
Engineered Nanomaterials ◽  
Ag Nps ◽  
Au Nanoclusters ◽  
New Approach ◽  
Technological Barrier ◽  
Shape Controlled

Nanomaterials with very specific features (purity, colloidal stability, composition, size, shape, location…) are commonly requested by cutting-edge technologic applications, and hence a sustainable process for the mass-production of tunable/engineered nanomaterials would be desirable. Despite this, tuning nano-scale features when scaling-up the production of nanoparticles/nanomaterials has been considered the main technological barrier for the development of nanotechnology. Aimed at overcoming these challenging frontier, a new gas-phase reactor design providing a shorter residence time, and thus a faster quenching of nanoclusters growth, is proposed for the green, sustainable, versatile, cost-effective, and scalable manufacture of ultrapure engineered nanomaterials (ranging from nanoclusters and nanoalloys to engineered nanostructures) with a tunable degree of agglomeration, composition, size, shape, and location. This method enables: (1) more homogeneous, non-agglomerated ultrapure Au-Ag nanoalloys under 10 nm; (2) 3-nm non-agglomerated ultrapure Au nanoclusters with lower gas flow rates; (3) shape-controlled Ag NPs; and (4) stable Au and Ag engineered nanostructures: nanodisks, nanocrosses, and 3D nanopillars. In conclusion, this new approach paves the way for the green and sustainable mass-production of ultrapure engineered nanomaterials.

TEM evaluation of graded SixGe1-x heterolayers

1991 ◽  
Vol 49 ◽  
pp. 894-895
Author(s):  
N. David Theodore ◽  
Mamoru Tomozane ◽  
Ming Liaw
Keyword(s):  
Heterojunction Bipolar Transistors ◽  
Gas Flow ◽  
Field Effect Transistors ◽  
Chemical Vapor ◽  
Dark Field ◽  
Bipolar Transistors ◽  
Structural Quality ◽  
Weak Beam ◽  
Transmission Electron ◽  
And Behavior

There is extensive interest in SiGe for use in heterojunction bipolar transistors. SiGe/Si superlattices are also of interest because of their potential for use in infrared detectors and field-effect transistors. The processing required for these materials is quite compatible with existing silicon technology. However, before SiGe can be used extensively for devices, there is a need to understand and then control the origin and behavior of defects in the materials. The present study was aimed at investigating the structural quality of, and the behavior of defects in, graded SiGe layers grown by chemical vapor deposition (CVD).The structures investigated in this study consisted of Si1-xGex[x=0.16]/Si1-xGex[x= 0.14, 0.13, 0.12, 0.10, 0.09, 0.07, 0.05, 0.04, 0.005, 0]/epi-Si/substrate heterolayers grown by CVD. The Si1-xGex layers were isochronally grown [t = 0.4 minutes per layer], with gas-flow rates being adjusted to control composition. Cross-section TEM specimens were prepared in the 110 geometry. These were then analyzed using two-beam bright-field, dark-field and weak-beam images. A JEOL JEM 200CX transmission electron microscope was used, operating at 200 kV.

Electron Microscopy/Diffraction Study of the Ternary Mn-Er-S System

1990 ◽  
Vol 48 (1) ◽  
pp. 76-77
Author(s):  
A. R. Landa Canovas ◽  
L.C. Otero Diaz ◽  
T. White ◽  
B.G. Hyde
Keyword(s):  
Electron Microscopy ◽  
Gas Flow ◽  
Graphite Crucible ◽  
Nominal Composition ◽  
X Ray Diffraction ◽  
Alumina Crucible ◽  
X Ray ◽  
Intermediate Phases ◽  
Twin Band ◽  
Ar Gas

X-Ray diffraction revealed two intermediate phases in the system MnS+Er2S3,:MnEr2S4= MnS.Er2S3, and MnEr4S7= MnS.2Er2S3. Their structures may be described as NaCl type, chemically twinned at the unit cell level, and isostructural with CaTi2O4, and Y5S7 respectively; i.e. {l13} NaCl twin band widths are (4,4) and (4,3).The present study was to search for structurally-related (twinned B.) structures and or possible disorder, using the more sensitive and appropiate technigue of electron microscopy/diffraction.A sample with nominal composition MnEr2S4 was made by heating Mn3O4 and Er2O3 in a graphite crucible and a 5% H2S in Ar gas flow at 1500°C for 4 hours. A small amount of this material was thenannealed, in an alumina crucible, contained in sealed evacuated silica tube, for 24 days at 1100°C. Both samples were studied by X-ray powder diffraction, and in JEOL 2000 FX and 4000 EX microscopes.

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