Potassium Sulfate: A New Candidate to Explore Non-Photochemical Laser-Induced Nucleation Mechanisms

Abstract

In this paper, we report a study on the nucleation behavior of potassium sulfate (K2SO4) from aqueous solutions under the influence of unfocused nanosecond laser pulses. The objective is to contribute to the general understanding of the Non-Photochemical Laser-Induced Nucleation (NPLIN) mechanism. First, the influence of several parameters such as supersaturation as well as laser parameters (pulse energy, number of pulses, and laser polarization) on induction time, probability of nucleation and mean number of crystals in comparison with spontaneous nucleation was investigated. Then, we examined the influence of gas composition (i.e., degassing and gas bubbling (CO2 and N2)) of the supersaturated solutions on the NPLIN kinetics, showing no correlation between gas content (or nature) on the crystallization behavior. Our study questions the role of impurities within the solution regarding the mechanism of laser-induced nucleation.

Strong Enhancement of Nucleation Efficiency of Aqueous Ethylenediamine Sulfate Solutions by Nonphotochemical Laser-Induced Nucleation: Investigations on the Role of Solid Impurities in the Mechanism

“…3 × 3 × 4 mm 3 ) crystals were obtained. It should be underlined that no gas cavitation was observed during any of our experiments, but it is possible that gas cavities formed were too small or short-lived to be observed by the naked eye . In contrast, the nonirradiated solutions (control samples) remained metastable for at least 3 weeks but mostly up to 2 years, even when moved or shaken, highlighting the existence of a very large metastable domain in this system.…”

“…It should be underlined that no gas cavitation was observed during any of our experiments, but it is possible that gas cavities formed were too small or short-lived to be observed by the naked eye. 13 In contrast, the nonirradiated solutions (control samples) remained metastable for at least 3 weeks but mostly up to 2 years, even when moved or shaken, highlighting the existence of a very large metastable domain in this system. Lower or higher supersaturation ratios were also investigated and resulted in similar observations: all of the experiments reported in this publication were thus systematically performed at β = 1.10.…”

“…NPLIN Setup. The NPLIN setup used was the same as that described by Briard et al 13 and is illustrated in Figure 1A. The laser used was a Q-switched Nd-YAG laser NL300 (EKSPLA, Vilnius, Lituania).…”

“…Non-photochemical laser-induced nucleation (NPLIN) is the phenomenon where crystal nucleation is triggered by using laser irradiation, usually emitted by an unfocused nanosecond pulsed laser, without a photochemical reaction. It has been used to induce the nucleation of several compounds, either organic − or inorganic, − either from metastable supersaturated solutions or from the supercooled state, − resulting in the publication of more than 40 scientific articles since its discovery in 1996 . The phenomenon is attractive from an engineering perspective as it permits to reduce induction times for nucleation ( i.e.…”

Enantioselectivity in Chiral Crystallization Driven by the Canonical and Spin Momentum Forces of Optical Vortex Beams

“…28 This study focuses on optical control over the chirality of ethylenediamine sulfate (EDS) crystals nucleated by a focused LG beam. EDS has been widely employed as a model organic compound in experiments on chiral crystallization and exhibits chiral crystallization without metastable phase, 29,30 unlike NaClO 3 , which shows complicated polymorphic transition. 31,32 Optical trapping initiates chiral crystallization by capturing molecular clusters at the LG beam focus.…”