Transformations of Hydrates into Instable Hydrates. The Crystallisation of CaCl2-Hydrates in Quartz Flasks.

High-pressure transformations in xenon hydrates.

A high-pressure investigation of the Xe*H(2)O chemical system was conducted by using diamond-anvil cell techniques combined with in situ Raman spectroscopy, synchrotron x-ray diffraction, and laser heating. Structure I xenon clathrate was observed to be stable up to 1.8 GPa, at which pressure it transforms to a new Xe clathrate phase stable up to 2.5 GPa before breaking down to ice VII plus sol...

Hydrates of tin tetrachloride.

The crystal structures of the tri- and tetrahydrate of tin tetrachloride, viz. diaquatetrachlorotin(IV) monohydrate, [SnCl(4)(H(2)O)(2)].H(2)O, and diaquatetrachlorotin(IV) dihydrate, [SnCl(4)(H(2)O)(2)].2H(2)O, are reported and shown to contain the cis-[SnCl(4)(H(2)O)(2)] species and water molecules in both cases. The trihydrate contains chains of the tin species linked by a single hydrogen-bo...

Clathrate hydrates in nature.

Scientific knowledge of natural clathrate hydrates has grown enormously over the past decade, with spectacular new findings of large exposures of complex hydrates on the sea floor, the development of new tools for examining the solid phase in situ, significant progress in modeling natural hydrate systems, and the discovery of exotic hydrates associated with sea floor venting of liquid CO2. Majo...

Nucleation of gas hydrates

The kinetics of nucleation of one-component gas hydrates in aqueous solutions are analyzed. The size of the hydrate nucleus and the work for nucleus formation are determined as functions of the supersaturation Dm: Expressions for the stationary rate J of hydrate nucleation are derived. These expressions describe the JðDmÞ dependence for homogeneous nucleation and for heterogeneous nucleation at...

Hydrates of Natural Gas