Single laser pulse induced aggregation of gold nanoparticles

Abstract

Gold nanoparticles with an average diameter of 11 nm (Au(39000)) were prepared in an SDS aqueous solution. A 80-microm liquid droplet (microdroplet) of the solution was ejected into the atmosphere from a microdroplet nozzle. Structural changes of the gold nanoparticles in the microdroplet, after they were irradiated with a focused single-nanosecond laser pulse at the wavelength of 532 nm, were studied by transmission electron microscopy (TEM) and optical absorption spectroscopy. It was revealed that the gold nanoparticles are fragmented into small particles and then the small fragments aggregate with each other. The aggregation was found to be terminated 100 micros after the laser-pulse excitation.

Laser ablation synthesis in solution and size manipulation of noble metal nanoparticles

“…[101][102][103] In presence of stabilizers, the average size of particles after fragmentation is reduced than in pure water, which confirmed that fragments are inclined to regrow. [101][102][103] According to these results, the minimum diameter is determined by the equilibrium between the efficiency of fragmentation and reaggregation. [101][102][103] For low aggregation efficiency, the minimum diameter can be reached by sequential irradiation with more than one laser pulse.…”

“…Mafune´and co. investigated also the fate of AuNP fragments in presence or absence of stabilizers. 62,87,[101][102][103] They found that fragments can coalesce forming spherical particles or, when present with high concentration, elongated fractal structures. [101][102][103] In presence of stabilizers, the average size of particles after fragmentation is reduced than in pure water, which confirmed that fragments are inclined to regrow.…”

“…62,87,[101][102][103] They found that fragments can coalesce forming spherical particles or, when present with high concentration, elongated fractal structures. [101][102][103] In presence of stabilizers, the average size of particles after fragmentation is reduced than in pure water, which confirmed that fragments are inclined to regrow. [101][102][103] According to these results, the minimum diameter is determined by the equilibrium between the efficiency of fragmentation and reaggregation.…”

“…[101][102][103] According to these results, the minimum diameter is determined by the equilibrium between the efficiency of fragmentation and reaggregation. [101][102][103] For low aggregation efficiency, the minimum diameter can be reached by sequential irradiation with more than one laser pulse. Size reduction of gold nanoparticles in presence of SDS produced particles smaller than 2 nm with about 20% of standard deviation.…”

Laser generated gold nanocorals with broadband plasmon absorption for photothermal applications

“…[64][65][66][67][68] It has been reported also that Au atoms and small clusters form during photofragmentation of Au nanoparticles in liquid phase. 54,69 Photofragmentation of Au nanospheres contributes to F ab also by increasing the concentration of Au particles and solution temperature. 54,69 Photofragmentation of Au nanospheres contributes to F ab also by increasing the concentration of Au particles and solution temperature.…”