Magnesium Nanoparticle Synthesis from Powders via Pulsed Laser Ablation in Liquid for Nanocolloid Production

Magnesium nanoparticles of various mean diameters (53-239 nm) were synthesised in this study via pulsed laser ablation in liquid (PLAL) from millimetre sized magnesium powders within isopropyl alcohol. It was observed via a 3 x 3 full factorial design of experiments that the processing parameters can control the nanoparticle distribution to produce three size-distribution types (bimodal, skewed and normal). Ablation times of 2, 5, and 25 min where investigated. An ablation time of 2 min produced a bimodal distribution with the other types seen at higher periods of processing. Mg nanoparticle Ultraviolet-Visible spectroscopy (UV-Vis) absorbance at 204 nm increased linearly with increasing ablation time, indicating an increase in nanoparticle count. The colloidal density (mg/mL) generally increased with increasing nanoparticle mean diameter as noted via increasing UV-Vis absorbance. High laser scan speeds (within the studied range of 3000-3500 mm/s) tend to increase the nanoparticle count/yield. For the first time, the effect of scan speed on colloidal density, UV-Vis absorbance and nanoparticle diameter from metallic powder ablation was investigated and is reported herein. The nanoparticles formed dendritic structures after being drop cast on aluminium foil as observed via field emission scanning electron microscope analysis. Dynamic light scattering was used to measure the size of the nanoparticles. Magnesium nanoparticle inks show promise for use in the fabrication conductive tracks or thermal insulation in electronics.

Automated summary

Magnesium nanoparticles were synthesized via pulsed laser ablation in liquid from millimeter-sized magnesium powders. The processing parameters can control the nanoparticle distribution to produce different size-distribution types. Ablation time and laser scan speed have effects on nanoparticle properties, with nanoparticles forming dendritic structures.