Effects of water depth and laser pulse numbers on size properties of colloidal nanoparticles prepared by nanosecond pulsed laser ablation in liquid

• Colloidal Al and Ti based nanoparticles synthesized by pulsed laser ablation in water.
• Depth of water above the targets and pulse numbers were used as variable parameters.
• Effects of liquid depth and pulse numbers on nanoparticle formation are described.
• Size properties of prepared nanoparticles depend on the liquid depth above the target.
• Large pulse numbers produces small mean size nanoparticles with narrow distributions.

In this paper, pulsed laser ablation method was used for synthesis of colloidal nanoparticles of aluminum and titanium in a distilled water medium. The interaction was performed in a water cell in which the target was placed at different depths of water. The effects of the number of laser pulses and the water depth in which the interaction occurred on average size and size distribution of prepared colloidal nanoparticles were investigated. A UV–vis absorption spectrophotometer and a scanning electron microscope were used for the characterization of the produced nanoparticles. Using image processing techniques and analyzing the SEM images, nanoparticles size properties were achieved. According to the results, position of the target in different water depths has strong effect on size properties of the synthesized nanoparticles. Our results also showed that higher number of laser pulses produces smaller mean size nanoparticles with narrower size distribution.