Automated iterative batch processing of submicrometer spherical particles by pulsed laser melting in liquid

Abstract Nonporous, submicrometer spherical particles can be fabricated by pulsed laser melting in liquid. In this process, particles dispersed in liquid absorb laser light, instantaneously heated above melting point, and quenched to form submicrometer spherical particles. The dispersed raw particles can only be heated from the laser beam direction, and thus the surface layer facing laser beam is reaction zone. Two automated iterative batch processing apparatuses with different cell sizes were developed to fabricate large quantities of submicrometer spherical particles by efficient use of liquid surface layer. Model calculations indicated that the formation rate will be higher when smaller cells and frequent cell exchange are adopted. This is experimentally confirmed with the fabrication of submicrometer spherical silver particles. The overall production rate of the iterative process with smaller cells was 5.15 mg h−1. However, the smaller cells imposed several limitations, including difficult sample agitation and stray light effects.