Speaker
Description
We provide an original experimental approach to induce controlled freezing and thawing at a solid-liquid interface in view of imaging the process at nano-scale resolution. The study is framed in the broad context of the assessment of the key drivers promoting ice formation in the presence of a substrate such as minerals. In this sense, observing and quantifying formation and behavior of ice at solid-liquid interfaces is a critical research area. It bears significant implications in, e.g., geochemistry (in the context of chemical and mechanical weathering of rocks), climate science (with reference to the formation of ice on mineral dust in the atmosphere and permafrost thawing), or cryobiology (to optimize applications such as cryopreservation or unravel adaptation dynamics of microorganisms such as bacteria to extreme conditions). Traditional experimental techniques to analyze ice nucleation chiefly rely on exposing pre-cooled substrates to humid vapors. Doing so typically limits precision and control over key variables in interfacial studies. Our original experimental approach is specifically designed to overcome these limitations. We rely on Highly Oriented Pyrolytic Graphite (HOPG) as a model substrate and document controlled freezing. The latter is obtained by periodically cooling the interfacial layer while maintaining the bulk liquid water at a stable temperature above 0 °C. Nano-scale resolution imaging is obtained through Atomic Force Microscopy. Our experimental design enables us to achieve an accurate temperature control (about ±0.1 °C). This, in turn, allows minimizing drift issues during surface scans. We outline the design of our experimental set-up and the key elements of our unique combination of experimental methodologies. We then provide perspectives about broader implications of our findings to advance porous media science upon encompassing the effects of ice nucleation dynamics and interfacial processes on the structure of complex pore spaces.
| Country | Italy |
|---|---|
| Water & Porous Media Focused Abstracts | This abstract is related to Water |
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