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Updated: Jan 29, 2026
08:01
A Microfluidic Approach for the Study of Ice and Clathrate Hydrate Crystallization
Published on: August 18, 2022
3.5K
Ice crystallization observed in highly supercooled confined water
E Stefanutti1, L E Bove, G Lelong
1Dipartimento di Scienze, Università degli Studi Roma Tre, Via della Vasca Navale 84, 00146 Roma, Italy. fabio.bruni@uniroma3.it.
Physical Chemistry Chemical Physics : PCCP
|February 14, 2019
Summary
Confined water in mesoporous silica exhibits a liquid to ice transition. A fraction of freezable water coexists with non-freezable water, influencing structural changes observed via neutron scattering and diffraction.
Area of Science:
- Materials Science
- Physical Chemistry
- Condensed Matter Physics
Background:
- Water behavior within nanoporous materials deviates significantly from bulk water.
- Understanding confined water is crucial for applications in catalysis, energy storage, and separation technologies.
Purpose of the Study:
- To investigate the phase behavior of water confined in MCM-41 mesoporous silica with varying pore sizes (2.8 nm and 4.5 nm).
- To elucidate the cause of the observed temperature-dependent structural changes in confined water.
Main Methods:
- Combined small-angle neutron scattering (SANS) and wide-angle neutron diffraction (WAND).
- Temperature range: 160-290 K.
- Analysis of intermolecular correlations, pore arrangement, and interfacial scattering.
Main Results:
- Identified coexistence of freezable and non-freezable water fractions within the pores.
- Observed a liquid to ice transition in the freezable water fraction.
- Attributed the variation in Bragg peak intensity to this phase transition, not a density minimum.
Conclusions:
- The temperature dependence of structural features in confined water is primarily driven by the freezing of a fraction of the water.
- The presence of non-freezable water layers influences the overall behavior.
- Experimental evidence clarifies previous interpretations of confined water's phase transitions.
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