A hierarchical view on material formation during pulsed-laser synthesis of nanoparticles in liquid

Abstract

Pulsed-laser assisted nanoparticle synthesis in liquids (PLAL) is a versatile tool for nanoparticle synthesis. However, fundamental aspects of structure formation during PLAL are presently poorly understood. We analyse the spatio-temporal kinetics during PLAL by means of fast X-ray radiography (XR) and scanning small-angle X-ray scattering (SAXS), which permits us to probe the process on length scales from nanometers to millimeters with microsecond temporal resolution. We find that the global structural evolution, such as the dynamics of the vapor bubble can be correlated to the locus and evolution of silver nanoparticles. The bubble plays an important role in particle formation, as it confines the primary particles and redeposits them to the substrate. Agglomeration takes place for the confined particles in the second bubble. Additionally, upon the collapse of the second bubble a jet of confined material is ejected perpendicularly to the surface. We hypothesize that these kinetics influence the final particle size distribution and determine the quality of the resulting colloids, such as polydispersity and modality through the interplay between particle cloud compression and particle release into the liquid.

High‐Quality, Ligands‐Free, Mixed‐Halide Perovskite Nanocrystals Inks for Optoelectronic Applications

“…[35] However, other aspects of the nanoparticles formation are still not deeply explored, in particular the interaction of the plasma produced by the ablation (evaluated to be at higher than 2-3000 K) [36] with the solvent, which may decompose, leaving carbon materials on the nanoparticles surface as already proved, for example, for gold nanoparticles synthesized in toluene. In order to explain such results one should recall the fabrication methodology of the presented nanocrystals.…”

Discharge phenomena in a cavitation bubble induced by liquid-phase laser ablation

“…This may be a unique feature of the cavitation bubble induced by liquid-phase laser ablation, since the deformation of the cavitation bubble is not observed when it is produced by an ultrasonic power [26,27]. Since it has been found that the growth field of nanoparticles in liquid-phase laser ablation is the inside of the cavitation bubble [36][37][38][39][40], the present experimental results may explain the origin of the high zeta potential of the colloidal solution synthesized by liquid-phase laser ablation. …”

“…The experimental results are consistent with a model calculation which assumes free charges on the gas-liquid boundary. Since it has been shown that the growth field of nanoparticles in liquid-phase laser ablation is the inside of the cavitation bubble [36][37][38][39][40], it is suggested that the origin of the high zeta potential of the colloidal solution synthesized by liquid-phase laser ablation is the electrical charges stored in the cavitation bubble.…”

Fluence Threshold Behaviour on Ablation and Bubble Formation in Pulsed Laser Ablation in Liquids

“…[31,48] The chamber had three windows and four channels, two for target transport and two for water exchange. [31,48] The chamber had three windows and four channels, two for target transport and two for water exchange.…”