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Controlling the Size, Shape and Stability of Supramolecular Polymers in Water
Published on: August 2, 2012
"Similarities" between confined and supercooled water
Maria Antonietta Ricci1, Fabio Bruni, Alessia Giuliani
1Dipartimento di Fisica E. Amaldi, Università degli Studi Roma Tre, via della Vasca Navale 84, 00147 Roma, Italy. riccim@fis.uniroma3.it
Faraday Discussions
|February 21, 2009
Summary
Comparing bulk and confined water using neutron scattering reveals structural and dynamic changes. Confinement and supercooling alter hydrogen bonds and molecular arrangements, offering insights into water
Area of Science:
- Condensed Matter Physics
- Materials Science
- Physical Chemistry
Background:
- Water exhibits unique properties in bulk, supercooled, and confined states.
- Understanding these states is crucial for various scientific and technological applications.
- Neutron scattering techniques probe microscopic structure and dynamics.
Purpose of the Study:
- To compare the microscopic structure and proton dynamics of bulk water (stable and supercooled) with water confined in silica substrates.
- To elucidate the effects of confinement and supercooling on hydrogen bonding and molecular arrangements in water.
- To propose a model explaining observed changes in neutron scattering data.
Main Methods:
- Neutron diffraction experiments on bulk and confined water.
- Deep inelastic neutron scattering (DINS) experiments on bulk and confined water.
- Analysis of oxygen-oxygen radial distribution functions and hydrogen bond characteristics.
Main Results:
- Both supercooling and confinement lead to a closer average distance between neighboring oxygen sites and shorter hydrogen bonds.
- Confinement significantly reduces the number of hydrogen bonds per molecule and interstitial water molecules compared to bulk water.
- The second peak of the oxygen-oxygen radial distribution function shifts to shorter distances under confinement.
Conclusions:
- Confinement and supercooling induce distinct yet overlapping changes in water's microscopic structure and dynamics.
- The observed structural modifications under confinement impact hydrogen bond networks and molecular packing.
- A scenario is proposed to explain deep inelastic neutron scattering observations in confined and supercooled water.
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