Bimodal size distribution of gold nanoparticles in aqueous solution during pulsed laser irradiation

2004 ◽  
Vol 850 ◽  
Author(s):  
Susumu Inasawa ◽  
Masakazu Sugiyama ◽  
Yukio Yamaguchi
Keyword(s):  
Aqueous Solution ◽  
Gold Nanoparticles ◽  
Size Distribution ◽  
Laser Irradiation ◽  
Pulsed Laser ◽  
Laser Wavelength ◽  
Bimodal Size Distribution ◽  
Transmission Electron ◽  
Two Peaks ◽  
Pulsed Laser Irradiation

ABSTRACTSize distribution of gold nanoparticles in aqueous solution during pulsed laser irradiation (Nd:YAG laser, wavelength of 355 nm, pulse width 30 ps) is observed by transmission electron microscope (TEM). Interestingly, we observed that a single peak distribution of gold nanoparticles sizes (initially centered around 25 nm) is gradually turned into a two-peaks one upon laser radiation. Initial particles reduced their sizes and smaller particles were formed, resulting in the bimodal size distribution. In these bimodal size distributions, two peaks are observed, one is at 6 nm, and another is at 24 nm.

Fabrication of gold nanoparticles in intense optical field by femtosecond laser irradiation of aqueous solution

2008 ◽  
Vol 23 (4) ◽  
pp. 968-974 ◽  
Author(s):  
Takahiro Nakamura ◽  
Yuzuru Mochidzuki ◽  
Shunichi Sato
Keyword(s):  
Aqueous Solution ◽  
Gold Nanoparticles ◽  
Femtosecond Laser ◽  
Size Distribution ◽  
Laser Irradiation ◽  
Optical Field ◽  
Femtosecond Laser Irradiation ◽  
Gold Particles ◽  
Transmission Electron ◽  
The Mean

Gold particles were fabricated by the high-intensity femtosecond laser irradiation of gold (III) chloride trihydrate (HAuCl4) aqueous solution. The structure and size distribution of the prepared particles were evaluated by transmission electron microscopy. The configuration of the gold particles varied with the concentration of the HAuCl4 aqueous solution. The mean particle size and size distribution were changed by the addition of polyvinylpyrrolidone (PVP), which acted as a dispersant, and monodispersed gold nanoparticles with a diameter of about 3 nm were successfully fabricated. The formation process of the nanoparticles is discussed in terms of the optical decomposition of molecules in the highly intense optical field generated by femtosecond laser irradiation.

Size reduction of gold particles in aqueous solution by pulsed laser irradiation

1998 ◽  
Vol 72 (7) ◽  
pp. 789-791 ◽  
Author(s):  
Hideaki Kurita ◽  
Akinori Takami ◽  
Seiichiro Koda
Keyword(s):  
Aqueous Solution ◽  
Laser Irradiation ◽  
Pulsed Laser ◽  
Size Reduction ◽  
Gold Particles ◽  
Pulsed Laser Irradiation

siRNA release from gold nanoparticles by nanosecond pulsed laser irradiation and analysis of the involved temperature increase

2018 ◽  
Vol 11 (9) ◽  
pp. e201700329 ◽  
Author(s):  
Florian Rudnitzki ◽  
Susanne Feineis ◽  
Ramtin Rahmanzadeh ◽  
Elmar Endl ◽  
Johanna Lutz ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Laser Irradiation ◽  
Temperature Increase ◽  
Pulsed Laser ◽  
Nanosecond Pulsed Laser ◽  
Pulsed Laser Irradiation

Photofusion and Disaggregation of Silver Nanoparticles Suspended in Ethanol by Laser Irradiation

2017 ◽  
Vol 14 (1) ◽  
pp. 50-53 ◽  
Author(s):  
Gabriel Ortega-Mendoza ◽  
Oscar Goiz ◽  
Alfonso Padilla-Vivanco ◽  
Carina Toxqui-Quitl ◽  
Placido Zaca-Moran ◽  
...  
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Particle Size Distribution ◽  
Optical Fiber ◽  
Size Distribution ◽  
Laser Irradiation ◽  
Absorption Spectra ◽  
Colloidal Solution ◽  
Pulsed Laser ◽  
Pulsed Laser Irradiation

Background: Metal nanoparticles have been widely investigated due to their unique optical, mechanical, and chemical properties compared with those of the same bulk material. These properties can be tuned by controlling their size or shape, in this sense, several nanomaterials have been obtained by means of both chemical and physical methods. For instance, silver nanoparticles have been obtained in liquid media by using laser ablation or chemical reduction techniques. Another way to obtain a colloidal silver nanoparticles is through the well-known pulsed laser irradiation method which can produce a stable colloidal solution in a few minutes of irradiation and without stabilizing molecules or ligands. Methods: Silver nanopowder suspended in ethanol was irradiated with a pulsed laser at 532 nm via optical fiber. Previously, the fiber was prepared by cleaving and removing its coating and then placed in the middle of a cell. The pulse width was 15 ns and the pulse repetition frequency was 10 kHz. Scanning and transmission electron microscopes were used to observe the silver nanoparticles before and after laser irradiation, respectively. The samples were analyzed by means of UV-Vis spectrophotometer to observe the absorption spectra. Results: The absorption spectra show that particle size distribution increases according to the irradiation time. The colloidal solution showed a color change (from gray to yellow) after having irradiated it for 5 minutes. From TEM images, it can be observed that silver nanopowder was transformed to semispherical particles with diameters smaller than 1μm, however, due to the wide particle size distribution the colloidal solution was centrifuged for 30 min to separate the nanoparticles. Conclusion: The pulsed laser irradiation method via optical fiber was successfully used to obtain a stable yellow colloidal solution. Photomelting, photofusion, and photofragmentation are the responsible phenomena for the change in morphology and size of the silver nanopowder.

scholarly journals On The Origin of Laser-Induced Surface Activation of Ceramics

1995 ◽  
Vol 397 ◽  
Author(s):  
A.J. Pedraza ◽  
J.W. Park ◽  
D.H. Lowndes ◽  
S. Cao ◽  
W.R. Allen
Keyword(s):  
Laser Irradiation ◽  
Electroless Deposition ◽  
Pulsed Laser ◽  
Metallic Aluminum ◽  
Cross Sectional ◽  
Deposition Kinetics ◽  
Reducing Atmosphere ◽  
Oxidizing Atmosphere ◽  
Transmission Electron ◽  
Pulsed Laser Irradiation

ABSTRACTThe surfaces of Al2O3 and AlN are modified by pulsed-laser irradiation This modification promotes the deposition of copper when the irradiated substrates are immersed in an electroless bath. In this paper the nature of the surface modification is analyzed using results from Auger Emission Spectroscopy (AES) and Cross Sectional Transmission Electron Microscopy (XTEM). During irradiation AlN thermally decomposes leaving a discontinuous metallic film on the surface. A film of Al2O3 is detected at the surface of the irradiated AlN substrate, much thicker when the irradiation is performed in an oxidizing atmosphere than when done in a reducing one. Nanoparticles of metallic aluminum are generated during laser irradiation of Al2O3 in a reducing atmosphere. When the irradiation of Al2O3 is performed in an oxidizing atmosphere, regions containing aluminum or substoichiometric alumina are detected by AES. It is concluded that the presence of metallic aluminum is the main reason why electroless deposition can occur in both AlN and Al2O3. Deposition kinetics are completely consistent with this conclusion. It is very likely that also substoichiometric alumina helps to catalyze the electroless deposition.

Laser-induced microstructural changes and decomposition of aluminum nitride

1995 ◽  
Vol 10 (1) ◽  
pp. 54-62 ◽  
Author(s):  
Siqi Cao ◽  
A.J. Pedraza ◽  
L.F. Allard
Keyword(s):  
Laser Irradiation ◽  
Fine Particles ◽  
Laser Energy ◽  
Pulsed Laser ◽  
Solid Substrate ◽  
Sharp Change ◽  
Microstructural Changes ◽  
Transmission Electron ◽  
Electroless Copper ◽  
Pulsed Laser Irradiation

The microstructural changes induced by pulsed laser irradiation in the surface layer of AlN and the initial stage of electroless copper deposition in laser processe specimens have been investigated using transmission electron microscopy (TEM). It was found that a dislocation microstructure is generated by laser processing at laser energy densities of 1.5 J/cm2 or higher. A very sharp change in the dislocation microstructure was seen at a depth of 0.2 to 0.3 μm from the free surface. The dislocation Burgers vector is 〈100〉 and the slip plane is {001}, in agreement with previous reports. AlN was melted and resolidified homo-epitactically from the solid substrate forming a mosaic microstructure with very fine cells having a misorientation of up to 15°. Patches of metallic aluminum were found at the surface of all the specimens irradiated at a laser energy density of 1.5 J/cm2 or higher. Very fine particles of AlN, 20 to 50 nm in diameter, were randomly distributed inside the patches. Immersion of these specimens in an electroless copper bath showed that the electroless solution preferentially etched away aluminum at the Al-AlN interface. At the same time copper islands were deposited in cavities left by AlN particles as well as at the interface with the underlying substrate. These regions are the seeds for further electroless deposition. The TEM observations of laser-induced microstructural changes reported in this paper help to unravel further the mechanisms of adhesion enhancement and surface activation by pulsed laser irradiation.

scholarly journals Triggering gold nanoparticles formation on a quartz surface by nanosecond pulsed laser irradiation

RSC Advances ◽  
2021 ◽  
Vol 11 (36) ◽  
pp. 22419-22425
Author(s):  
P. A. Mercadal ◽  
S. D. García Schejtman ◽  
F. P. Cometto ◽  
A. V. Veglia ◽  
E. A. Coronado
Keyword(s):  
Gold Nanoparticles ◽  
Laser Irradiation ◽  
Pulsed Laser ◽  
Quartz Surface ◽  
Au Nps ◽  
Nanosecond Pulsed Laser ◽  
Pulsed Laser Irradiation

Naked Au NPs formation on a quartz surface by nanosecond pulsed laser irradiation.

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