Influence of Surfactant Concentration on Laser-Based Gold Nanoparticle Formation and Stability

2012 ◽  
Vol 65 (2) ◽  
pp. 97 ◽  
Author(s):  
Yuen-Yan Fong ◽  
Jason R. Gascooke ◽  
Gregory F. Metha ◽  
Mark A. Buntine
Keyword(s):  
Critical Micelle Concentration ◽  
Laser Irradiation ◽  
Gold Nanoparticle ◽  
Sodium Dodecylsulfate ◽  
Formation Kinetics ◽  
Transmission Electron ◽  
Bulk Gold ◽  
Microscopy Images ◽  
Apparent Influence

The time evolution of gold nanoparticle (AuNP) yields by in-situ laser irradiation from bulk gold in aqueous solutions containing the surfactant sodium dodecylsulfate (SDS) at concentrations above and below the critical micelle concentration in water is reported. These studies are augmented by transmission electron microscopy images of AuNP samples at each SDS concentration recorded after 90 min of laser irradiation. The results show that while a low concentration of SDS plays a role in the formation kinetics, there is no apparent influence of the SDS concentration around the surfactant critical micelle concentration on particle size during AuNP production.

Novel Ultrathin Mg Nanoblades for Hydrogen Storage

2009 ◽  
Vol 1216 ◽  
Author(s):  
Fu Tang ◽  
Gwo Ching Wang ◽  
Toh-Ming Lu
Keyword(s):  
Electron Microscopy ◽  
Thermal Desorption Spectroscopy ◽  
High Energy ◽  
Oblique Angle ◽  
Temperature Dependent ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
Composition Changes ◽  
Microscopy Images

AbstractWe describe the growth of novel ultrathin Mg crystalline nanoblades by oblique angle vapor deposition. These nanoblades were then coated with catalyst Pd and hydrogenated into magnesium hydride MgH2. In situ thermal desorption spectroscopy study showed a low H desorption temperature at ∼365 K. In situ reflection high energy electron diffraction patterns were used to study the temperature dependent structure and composition changes during the de-hydrogenation of Pd coated MgH2 nanoblades. The diffraction rings reveal the formation of alloys of Pd and Mg when the temperature is over ∼480 K. Transmission electron microscopy diffraction also supports the formation of Pd and Mg alloys. This alloying reduces the cycling capability of Mg hydride. The de-hydrogenation of MgH2 introduces a strain at the bilayer interface between MgH2 and Mg resultant from 30% volume reduction from MgH2 to Mg and formed curved nanoblades as evident by scanning electron microscopy images. Designing factors of recyclable simple hydrides will be discussed.

scholarly journals In Situ Local Oxidation of SnO Induced by Laser Irradiation: A Stability Study

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 976
Author(s):  
Antonio Vázquez-López ◽  
David Maestre ◽  
Julio Ramírez-Castellanos ◽  
Ana Cremades
Keyword(s):  
Raman Spectroscopy ◽  
Laser Irradiation ◽  
Stability Study ◽  
Thermal Treatments ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Local Oxidation ◽  
Potential Applicability ◽  
The Stability

In this work, semiconductor tin oxide (II) (SnO) nanoparticles and plates were synthesized at room conditions via a hydrolysis procedure. X-ray diffraction (XRD) and transmission electron microscopy (TEM) confirmed the high crystallinity of the as-synthesized romarchite SnO nanoparticles with dimensions ranging from 5 to 16 nm. The stability of the initial SnO and the controlled oxidation to SnO2 was studied based on either thermal treatments or controlled laser irradiation using a UV and a red laser in a confocal microscope. Thermal treatments induced the oxidation from SnO to SnO2 without formation of intermediate SnOx, as confirmed by thermodiffraction measurements, while by using UV or red laser irradiation the transition from SnO to SnO2 was controlled, assisted by formation of intermediate Sn3O4, as confirmed by Raman spectroscopy. Photoluminescence and Raman spectroscopy as a function of the laser excitation source, the laser power density, and the irradiation duration were analyzed in order to gain insights in the formation of SnO2 from SnO. Finally, a tailored spatial SnO/SnO2 micropatterning was achieved by controlled laser irradiation with potential applicability in optoelectronics and sensing devices.

NOVEL METHOD FOR THE SYNTHESIS OF SILOXANE NANOWIRES AND FILAMENTS USING GOLD NANOPARTICLE CATALYSTS

2005 ◽  
Vol 04 (05n06) ◽  
pp. 1007-1010
Author(s):  
B. L. V. PRASAD ◽  
S. STOEVA ◽  
C. M. SORENSEN ◽  
K. J. KLABUNDE ◽  
V. ZAIKOVSKII
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Gold Nanoparticles ◽  
Gold Nanoparticle ◽  
Polymerization Reaction ◽  
Nanoparticle Catalysts ◽  
Transmission Electron ◽  
Elemental Analyses ◽  
Novel Method ◽  
Microscopy Images

A unique polymerization reaction of alkylsilanes to siloxane nanowires, filaments and tubes in presence of gold nanoparticles and water is presented. The gold nanoparticles, which catalyze this reaction also work as templates restricting the shape of the resulting polymers into wires and tubes. High resolution transmission electron microscopy images clearly reveal the presence of gold nanoparticle at the tip of each wire supporting the template hypothesis. Elemental analyses by different methods confirm the stoichiometry to be C 18 H 37 SiO 1.5, when the alkylsilane used was C 18 H 37 SiH 3, thus proving that the alkyl group remains intact during the polymerization reaction.

scholarly journals Atomic mechanisms of gold nanoparticle growth in ionic liquids studied by in situ scanning transmission electron microscopy

Nanoscale ◽  
2020 ◽  
Vol 12 (44) ◽  
pp. 22511-22517
Author(s):  
Debora Keller ◽  
Trond R. Henninen ◽  
Rolf Erni
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ionic Liquids ◽  
Liquid Phase ◽  
Gold Nanoparticle ◽  
Scanning Transmission Electron Microscopy ◽  
Nanoparticle Growth ◽  
Transmission Electron ◽  
Scanning Transmission

This work reveals direct, experimental insights into dynamic, atomic mechanisms of gold nanoparticle growth in liquid phase by electron microscopy.

Bubble formation and growth in glasses

1998 ◽  
Vol 540 ◽  
Author(s):  
Xidong Chen ◽  
Robert C. Birtcher ◽  
S.E. Donnelly
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ion Beam ◽  
Bubble Formation ◽  
Gas Bubble ◽  
Transmission Electron ◽  
Amorphous Network ◽  
Alkali Silicate Glass ◽  
Microscopy Images

AbstractIn this study, we simulated gas bubble formation in glasses by in-situ ion implantation. Alkali silicate glass and Na-borosilicate glass were implanted in situ with 50 keV Xe ions at temperatures at 200°C in a Hitachi-9000 electron microscope. Bubble formation was studied by transmission electron microscopy images taken during interruptions of the ion beam after discrete implanted-ion dose steps. We present a possible mechanism of bubble formation and growth based on amorphous network structures.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

In situ REM imaging of surface processes on ceramic bulk crystals from 300 to 1670 K in a conventional TEM

1991 ◽  
Vol 49 ◽  
pp. 660-661
Author(s):  
Z. L. Wang ◽  
J. Bentley
Keyword(s):  
High Temperatures ◽  
Image Resolution ◽  
Atomic Processes ◽  
Crystal Surfaces ◽  
Beam Radiation ◽  
Surface Areas ◽  
Transmission Electron ◽  
Reflection Electron Microscopy ◽  
Gas Reactions

Studying the behavior of surfaces at high temperatures is of great importance for understanding the properties of ceramics and associated surface-gas reactions. Atomic processes occurring on bulk crystal surfaces at high temperatures can be recorded by reflection electron microscopy (REM) in a conventional transmission electron microscope (TEM) with relatively high resolution, because REM is especially sensitive to atomic-height steps.Improved REM image resolution with a FEG: Cleaved surfaces of a-alumina (012) exhibit atomic flatness with steps of height about 5 Å, determined by reference to a screw (or near screw) dislocation with a presumed Burgers vector of b = (1/3)<012> (see Fig. 1). Steps of heights less than about 0.8 Å can be clearly resolved only with a field emission gun (FEG) (Fig. 2). The small steps are formed by the surface oscillating between the closely packed O and Al stacking layers. The bands of dark contrast (Fig. 2b) are the result of beam radiation damage to surface areas initially terminated with O ions.

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