High-speed imaging of ice nucleation in water proves the existence of active sites
| Autor: | Mark D. Tarn, Daniel O'Sullivan, Richard Walshaw, Hugo K. Christenson, Mark A. Holden, Fiona C. Meldrum, Thomas F. Whale, Benjamin J. Murray |
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| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
F890
Multidisciplinary 010504 meteorology & atmospheric sciences F300 F100 Nucleation F200 SciAdv r-articles Cleavage (crystal) 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences law.invention Chemistry law Chemical physics Ice nucleus QD Crystallization 0210 nano-technology QC Research Articles Research Article 0105 earth and related environmental sciences |
| Zdroj: | Science Advances |
| ISSN: | 2375-2548 |
| Popis: | High-speed video of freezing water proves ice formation starts at specific and very rare sites where there are surface defects. Understanding how surfaces direct nucleation is a complex problem that limits our ability to predict and control crystal formation. We here address this challenge using high-speed imaging to identify and quantify the sites at which ice nucleates in water droplets on the two natural cleavage faces of macroscopic feldspar substrates. Our data show that ice nucleation only occurs at a few locations, all of which are associated with micron-size surface pits. Similar behavior is observed on α-quartz substrates that lack cleavage planes. These results demonstrate that substrate heterogeneities are the salient factor in promoting nucleation and therefore prove the existence of active sites. We also provide strong evidence that the activity of these sites derives from a combination of surface chemistry and nanoscale topography. Our results have implications for the nucleation of many materials and suggest new strategies for promoting or inhibiting nucleation across a wide range of applications. |
| Databáze: | OpenAIRE |
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