The moment of initial crystallization captured on functionalized nanoparticles

Hironobu Machida,Izumi Hirasawa,Takeshi Sugahara

doi:10.1038/s43246-021-00171-w

Hironobu Machida, Izumi Hirasawa + Show 1 more

Open Access

https://doi.org/10.1038/s43246-021-00171-w

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Journal: Communications Materials	Publication Date: Jun 18, 2021
Citations: 8	License type: open-access

Affiliation: Waseda University, Osaka University

Abstract

Even if a liquid is cooled below its melting point, the liquid state can be maintained under certain conditions. This state is called supercooling. Spraying fine particles of dry ice or silver iodide induces a phase change from supercooled droplets to ice grains. However, the mechanism by which crystallization seeds diminish supercooling is not well understood. Here, we captured the moment when a cluster, which is the smallest structural unit of a crystal, envelops a silver nanoparticle. As a result of observing the structure of a supercooled aqueous solution of a clathrate hydrate, we found that silver nanoparticles accelerate the formation of clusters, whereas the noble metals palladium, gold and iridium likewise form nanoparticles but do not promote crystallization. Our discoveries elucidate the mechanism of heterogeneous nucleation during a phase change in clathrate hydrates. We anticipate our discovery to be the starting point for the control of supercooling, a technique that can be applied to enhance the production efficiency and quality of manufactured products.

Highlights

Even if a liquid is cooled below its melting point, the liquid state can be maintained under certain conditions
We reveal the moment of initial crystallization, which is the formation of [10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30] nm clusters encircling silver (Ag) nanoparticles, in the tetra-n-butylammonium 3-methylpentanoate (TBA-3MP) and tetra-n-butylammonium 2-ethylbutyrate (TBA2EB) semiclathrate hydrate systems
The decomposition temperature of TBA-3MP semiclathrate hydrate coexisting with tetra-n-butylammonium fluoride (TBAF) and silver pentanoate (Ag-PA) is 278.1 ± 0.2 K at a mass fraction, wTBA-3MP, of 0.42 (Supplementary Fig. 1), which is the same as the reported decomposition temperature of TBA-3MP semiclathrate hydrate without any additives[29]

Summary

Introduction

Even if a liquid is cooled below its melting point, the liquid state can be maintained under certain conditions. In both the supercooled aqueous solution and the crystal, granular structures (called clusters) measuring [10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30] nm in diameter are present as a basic structural unit[16,17,18,19,20,21,22,23].

Results

Conclusion