scholarly journals Magnetic tuning of SERS hot spots in polymer-coated magnetic–plasmonic iron–silver nanoparticles

2019 ◽  
Vol 1 (7) ◽  
pp. 2681-2689 ◽  
Author(s):  
Stefano Scaramuzza ◽  
Stefano Polizzi ◽  
Vincenzo Amendola
Keyword(s):  
Silver Nanoparticles ◽  
Laser Ablation ◽  
Hot Spots ◽  
Colloidal Stability ◽  
Hot Spot ◽  
Laser Ablation In Liquid ◽  
Fe Nanoparticles ◽  
Magnetic Tuning ◽  
Hot Spot Formation ◽  
Spot Formation

Dynamic electromagnetic hot spot formation was studied in magnetic–plasmonic Ag–Fe nanoparticles obtained by laser ablation in liquid and coated with polymers to confer colloidal stability.

Hot Spot Histories in Energetic Materials

1992 ◽  
Vol 296 ◽  
Author(s):  
A. M. Mellor ◽  
D. A. Wiegand ◽  
K. B. Isom
Keyword(s):  
Hot Spots ◽  
Energetic Materials ◽  
Ignition Temperature ◽  
Hot Spot ◽  
Original Form ◽  
Independent Variables ◽  
Shock Impact ◽  
Similarities And Differences ◽  
Hot Spot Formation ◽  
Spot Formation

AbstractInterest in the mechanisms by which hot spots either grow to sustained reaction or are quenched results from the observation that the energy required to ignite a propellant or explosive can be significantly less than that needed to bulk heat a test specimen uniformly to its ignition temperature. This result is independent of the original form of non-thermal energy and has been used to interpret data for shock, impact, friction and electrostatic discharge (ESD) stimuli. We present new flowcharts which include 1) events resulting in hot spot formation and 2) subsequent pathways which lead to sustained reaction or quenching. The mechanism appears capable of categorizing and demonstrating the similarities and differences between hot spot growth or quenching, for impact and ESD stimuli. Sample confinement and temperature and stimulus duration are the independent variables whose roles are particularly clarified in the mechanism.

scholarly journals Antibacterial activity of silver nanoparticles obtained by pulsed laser ablation in pure water and in chloride solution

2016 ◽  
Vol 7 ◽  
pp. 465-473 ◽  
Author(s):  
Brunella Perito ◽  
Emilia Giorgetti ◽  
Paolo Marsili ◽  
Maurizio Muniz-Miranda
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Laser Ablation ◽  
Active Sites ◽  
Colloidal Stability ◽  
Pure Water ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Surface Reactivity ◽  
Laser Ablation In Liquid

Silver nanoparticles (AgNPs) have increasingly gained importance as antibacterial agents with applications in several fields due to their strong, broad-range antimicrobial properties. AgNP synthesis by pulsed laser ablation in liquid (PLAL) permits the preparation of stable Ag colloids in pure solvents without capping or stabilizing agents, producing AgNPs more suitable for biomedical applications than those prepared with common, wet chemical preparation techniques. To date, only a few investigations into the antimicrobial effect of AgNPs produced by PLAL have been performed. These have mainly been performed by ablation in water with nanosecond pulse widths. We previously observed a strong surface-enhanced Raman scattering (SERS) signal from such AgNPs by “activating” the NP surface by the addition of a small quantity of LiCl to the colloid. Such surface effects could also influence the antimicrobial activity of the NPs. Their activity, on the other hand, could also be affected by other parameters linked to the ablation conditions, such as the pulse width. The antibacterial activity of AgNPs was evaluated for NPs obtained either by nanosecond (ns) or picosecond (ps) PLAL using a 1064 nm ablation wavelength, in pure water or in LiCl aqueous solution, withEscherichia coliandBacillus subtilisas references for Gram-negative and Gram-positive bacteria, respectively. In all cases, AgNPs with an average diameter less than 10 nm were obtained, which has been shown in previous works to be the most effective size for bactericidal activity. The measured zeta-potential values were very negative, indicating excellent long-term colloidal stability. Antibacterial activity was observed against both microorganisms for the four AgNP formulations, but the ps-ablated nanoparticles were shown to more effectively inhibit the growth of both microorganisms. Moreover, LiCl modified AgNPs were the most effective, showing minimum inhibitory concentration (MIC) values in a restricted range of 1.0–3.7 µg/mL. An explanation is proposed for this result based on the increased surface reactivity of the metal surface due to the presence of positively charged active sites.

scholarly journals Observations of anomalous x-ray emission at early stages of hot-spot formation in deuterium-tritium cryogenic implosions

2021 ◽  
Vol 103 (2) ◽  
Author(s):  
R. C. Shah ◽  
S. X. Hu ◽  
I. V. Igumenshchev ◽  
J. Baltazar ◽  
D. Cao ◽  
...  
Keyword(s):  
Hot Spot ◽  
X Ray ◽  
Early Stages ◽  
Hot Spot Formation ◽  
Spot Formation

Novel Ag/Au/Pt trimetallic nanocages used with surface-enhanced Raman scattering for trace fluorescent dye detection

2014 ◽  
Vol 2 (34) ◽  
pp. 5550-5557 ◽  
Author(s):  
Tran Thi Bich Quyen ◽  
Wei-Nien Su ◽  
Ching-Hsiang Chen ◽  
John Rick ◽  
Jyong-Yue Liu ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Hot Spot ◽  
Surface Enhanced Raman Scattering ◽  
Signal Enhancement ◽  
Fluorescent Dye ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Enhanced Raman Scattering ◽  
Hot Spot Formation ◽  
Spot Formation

Trimetallic nanocages possess inter-metallic synergies among elements and are able to generate significant SERS signal enhancement due to “hot spot” formation.

Effect of Support on the Suppression of Hot Spot Formation in the Partial Oxidation of Methane

2009 ◽  
Vol 38 (7) ◽  
pp. 720-721 ◽  
Author(s):  
Tetsuya Shishido ◽  
Reina Morishima ◽  
Yusuke Yoshinaga ◽  
Sadao Hasegawa ◽  
Tsunehiro Tanaka
Keyword(s):  
Partial Oxidation ◽  
Hot Spot ◽  
Partial Oxidation Of Methane ◽  
Oxidation Of Methane ◽  
Effect Of Support ◽  
Hot Spot Formation ◽  
Spot Formation
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