High-pressure behavior of bikitaite: An integrated theoretical and experimental approach

Orazio Ferro, Simona Quartieri, Giovanna Vezzalini, Ettore Fois, Aldo Gamba, Gloria Tabacchi
  • American Mineralogist, October 2002, Mineralogical Society of America
  • DOI: 10.2138/am-2002-1018

Pressure effects on water wires

What is it about?

A 'water wire' is a zig-zag chain of water molecules running along one direction. This intriguing water structure actually exists inside a rare porous mineral - the zeolite bikitaite. We called the water wire 'one-dimensional ice', just because of its stability inside the porous host. Indeed, at ambient conditions, the behaviour of the water wire is more similar to ice than to liquid water: the molecules do not move away from their positions, and their ordered arrangement is preserved. Now the question is: what happens to the water wire at conditions different from the standard ones? Can the water chain resist to very high pressure?

Why is it important?

For the first time, we explored the effects of pressure on ordered chains of water molecules in nanometer-sized pores. With X-ray diffraction experiments and molecular dynamics simulations, we showed that the water chains still exist at high pressure conditions.

Perspectives

Gloria Tabacchi
university of insubria

A lot of the material in the natural world is held at extreme pressures, which are typically in the GigaPascal range and above (1 GIga Pascal (GPa) = about 10,000 atmospheres). The effects of such high pressures to matter are still largely unknown, especially at the molecular level. Experimentally, it is very difficult to determine how materials deform at these conditions. This information would be important to understand, for example, what's happening to the minerals at depth below the Earth's crust. In this study, we showed for the first time that the deformations induced by high pressure on zeolite materials can be determined from modeling studies based on experimental data and accurate calculations. Since then, this combined experimental-theoretical approach has been succesfully used on many other systems to explore the fascinating high-pressure regime.

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http://dx.doi.org/10.2138/am-2002-1018

The following have contributed to this page: Gloria Tabacchi