scholarly journals Evolution of the properties of nanomaterials obtained by pulsed laser ablation

2021 ◽  
Vol 2058 (1) ◽  
pp. 012014
Author(s):  
S Faizullayeva ◽  
S M Klimentov ◽  
A A Popov
Keyword(s):  
Laser Ablation ◽  
Metal Nanoparticles ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Nacl Solution ◽  
Ablation Process ◽  
Science And Engineering ◽  
Gold Colloids ◽  
Gold Silver ◽  
Gold Plate

Abstract The synthesis and application of metal and ceramic nanoparticle are significant subject in science and engineering. The metal nanoparticles such as gold, silver, and copper nanoparticles have more application in material science, nanomedicine, electronic, photonic, and art. One of the green methods for preparation of metal nanoparticles is laser ablation technique that offers a unique tool for nanofabrication of nanoparticles. In this work, gold colloids were prepared by pulsed laser ablation of high purity gold plate immersed in deionized water and 10μM NaCl solution. After ablation process, we study the change in the size distribution of nanoparticles after the ablation process for a month.

scholarly journals Effect of the Surface Chemical Composition and of Added Metal Cation Concentration on the Stability of Metal Nanoparticles Synthesized by Pulsed Laser Ablation in Water

2020 ◽  
Vol 10 (12) ◽  
pp. 4169 ◽  
Author(s):  
Helena Mateos ◽  
Rosaria A. Picca ◽  
Antonia Mallardi ◽  
Marcella Dell’Aglio ◽  
Alessandro De Giacomo ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Metal Oxides ◽  
Metal Nanoparticles ◽  
Colloidal Stability ◽  
Particle Surface ◽  
Pulsed Laser ◽  
Colloidal Suspensions ◽  
Pulsed Laser Ablation ◽  
Ζ Potential ◽  
Gold Silver

Metal nanoparticles (NPs) made of gold, silver, and platinum have been synthesized by means of pulsed laser ablation in liquid aqueous solution. Independently from the metal nature, all NPs have an average diameter of 10 ± 5 nm. The ζ-potential values are: −62 ± 7 mV for gold, −44 ± 2 mV for silver and −58 ± 3 for platinum. XPS analysis demonstrates the absence of metal oxides in the case of gold and silver NPs. In the case of platinum NPs, 22% of the particle surface is ascribed to platinum oxidized species. This points to a marginal role of the metal oxides in building the negative charge that stabilizes these colloidal suspensions. The investigation of the colloidal stability of gold NPs in the presence of metal cations shows these NPs can be destabilized by trace amounts of selected metal ions. The case of Ag+ is paradigmatic since it is able to reduce the NP ζ-potential and to induce coagulation at concentrations as low as 3 μM, while in the case of K+ the critical coagulation concentration is around 8 mM. It is proposed that such a huge difference in destabilization power between monovalent cations can be accounted for by the difference in the reduction potential.

scholarly journals Tribological and Thermal Transport of Ag-Vegetable Nanofluids Prepared by Laser Ablation

2020 ◽  
Vol 10 (5) ◽  
pp. 1779 ◽  
Author(s):  
Jaime Taha-Tijerina ◽  
Sadasivan Shaji ◽  
Sreed Sharma Kanakkillam ◽  
Maria Isabel Mendivil Palma ◽  
Karla Aviña
Keyword(s):  
Laser Ablation ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Ablation Process ◽  
Negative Effects ◽  
Mineral Oils ◽  
Manufacturing Operations ◽  
Laser Ablation Process ◽  
The Coefficient Of Friction ◽  
Maximum Improvement

Lubricants and fluids are critical for metal-mechanic manufacturing operations as they reduce the friction and wear of tooling and components, and serve as coolants to dissipate the heat generated in these operations. The proper application of these materials improves machine operative life and tooling, and decreases cost, energy, and time consumption for maintenance, damage, repairs, or the need to exchange pieces/components within the machinery. Natural or vegetable-based lubricants have emerged as a substitute for mineral oils, which harm the environment due to their low biodegradability and have negative effects on human health (e.g., causing skin/respiratory diseases). Thus, finding biocompatible and efficient lubricants has become a technology objective for researchers and industry. This study evaluates soybean-, corn-, and sunflower-based lubricants reinforced with silver (Ag) nanostructures by a pulsed laser ablation process. Thermal and tribological evaluations were performed with varying Ag contents, and temperature-dependent behavior was observed. Thermal conductivity improvements were observed for all nanofluids as the temperature and Ag concentration increased (between 15% and 24%). A maximum improvement of 24% at 50 °C and 10 min exposure time of the pulsed laser ablation process for soybean oil was observed. The tribological evaluations showed improvements in the load-carrying capacity of the vegetable oils, i.e., an increase from 6% to 24% compared to conventional materials. The coefficient of friction performance also showed enhancements with Ag concentrations between 4% and 15%.

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