Influence of Water Temperature on the Hydrodynamic Diameter of Gold Nanoparticles from Laser Ablation

Defined hydrodynamic properties of nanoparticle colloids are required for applications in dosimetry, rheology, or biosensing studies. During the generation of nanoparticles by laser ablation of a solid target in liquids, the temperature of the liquid increases, which may effect cavitation bubble and particle formation. We demonstrate that this temperature variation influences the hydrodynamic diameter of the resulting colloidal nanoparticles when a gold target is ablated by an IR femtosecond laser in water at different stabilized liquid temperatures in the range of 283-353 K. The maximum hydrodynamic diameter was observed at 330 K, the temperature at which the compressibility of water reaches its minimum. The formation of particles by condensation of ablated species in the liquid matrix or inside the confined cavitation bubble is discussed, as well as the influence of the physical properties of the liquid that vary with temperature, Such as viscosity and compressibility. The reduction of the hydrodynamic particle diameter at the higher compressible state of water indicates that a lower number of agglomerates are dispersed in the liquid, reducing the polydispersity index of the gold colloid.