Nonphotochemical Laser-Induced Nucleation in Levitated Supersaturated Aqueous Potassium Chloride Microdroplets

Abstract

We have observed nonphotochemical laser-induced nucleation (NPLIN) in levitated 8 pL microdroplets of supersaturated aqueous potassium chloride irradiated with nanosecond pulses of 532 nm light. A much higher supersaturation ratio S of 1.20 was required to observe NPLIN in a microdroplet, compared to the value of 1.06 for bulk solutions, attributed to a 40-million-fold lower nucleation rate in a microdroplet at S = 1.06 as a result of its much smaller volume. This finding has application to high spatial and temporal resolution pump–probe studies of nucleation in a containerless environment.