Size distribution evolution and viscosity effect on spherical submicrometer particle generation process by pulsed laser melting in liquid

Abstract

Spherical submicrometer particles (SMPs) can be fabricated by pulsed laser melting in liquid (PLML). In this process, raw nanoparticles dispersed in liquid are irradiated by a pulsed laser, heated over the melting point to generate molten droplets, and quenched to form SMPs. The particle size increment is caused by aggregating and merging raw particles in liquid by transient heating. In this study, the viscosity effect on the formation process of SMPs by PLML process is studied by changing aqueous glycerin solution concentration. In highly viscous liquid, smaller SMPs are generated due to the ineffective aggregation process. The temporal evolution of cumulative volume frequency of particles can be simulated, considering the constraints of the non-melting at larger size due to high heat capacity and evaporation for smaller particles by overheating. The SMP size can be controlled by viscosity of the liquid, prior disaggregation time, and liquid temperature.