Cavitation‐Free Continuous‐Wave Laser Ablation from a Solid Target to Synthesize Low‐Size‐Dispersed Gold Nanoparticles

Abstract

Continuous wave (CW) radiation from a Yb-fiber laser (central wavelength 1064 nm, power 1-200 W) was used to initiate ablation of a gold target in deionized water and to synthesize bare (unprotected) gold nanoparticles. We show that the formed nanoparticles present a single low-size-dispersed population with a mean size of the order of 10 nm, which contrasts with previously reported data on dual populations of nanoparticles formed during pulsed laser ablation in liquids. The lack of a second population of nanoparticles is explained by the absence of cavitation-related mechanism of material ablation, which typically takes place under pulsed laser action on a solid target in liquid ambience, and this supposition is confirmed by plume visualization tests. We also observe a gradual growth of mean nanoparticle size from 8-10 nm to 20-25 nm under the increase of laser power for 532 nm pumping wavelength, whereas for 1064 nm pumping wavelength the mean size 8-10 nm is independent of radiation power. The growth of the nanoparticles observed for 532 nm wavelength is attributed to the enhanced target melting and splashing followed by additional heating due to an efficient excitation of plasmons over gold nanoparticles. Bare, low-size-dispersed gold nanoparticles are of importance for a variety of applications, including biomedicine, catalysis, and photovoltaics. The use of CW radiation for nanomaterial production promises to improve the cost efficiency of this technology.

Nanoparticles Engineering by Pulsed Laser Ablation in Liquids: Concepts and Applications

“…Such laser techniques are interesting in many regards, as they enable the processing of photovoltaic cells [10], thermoelectric materials and devices [11], micro and nanosystems for energy storage and conversion [12,13], biodegradable and biocompatible NPs for food packaging [14] as well as vectors for drug and gene delivery [15,16]. The interest towards pure and electrostatically stabilized nanocolloids is well recognized [17][18][19][20][21]. Although nanotechnologies and nanomaterials have much potential to introduce innovative products and production processes in the food industry and in the biomedical field, they are facing major challenges in being cost-effective in the production of e.g., edible and nontoxic nano-delivery systems, or effective formulations that are safe for human consumption and drug treatments [22].…”

Incubation Effect of Pre‐Irradiation on Bubble Formation and Ablation in Laser Ablation in Liquids

“…The surface rather develops splash and finger structures, the latter having a micrometer diameter and thus efficiently modifying light reflection. The splash structure points towards a molten and ejected surface layer, similar even to irradiation and ablation with continuous‐wave irradiation . The part of material remaining in contact to the bulk quickly cools down and freezes.…”

“…The splash structure points towards a molten and ejected surface layer, similar even to irradiation and ablation with continuous-wave irradiation. [35] The part of material remaining in contact to the bulk quickly cools down and freezes. We did not find indications for a dominant correlation of the incubation with varied macroscopic roughness (different polishing states) for the different targets except for the obvious change in reflectivity.…”

Современное Состояние Использования Кавитационных Технологий (Краткий Обзор)

“…Кавитационный механизм абляции материала, который обычно имеет место при импульсном лазерном воздействии на твердую мишень, в жидкой среде сказывается на формировании популяции наночастиц металла [20]. Метод получения наночастиц коллоидных сплавов путем импульсной лазерной абляция в жидкостях рассматривается в работе [21].…”