Clathrate-hydrate ultrafast nucleation and crystallization from supercooled aqueous nanodroplets

One of the most vital properties of clathrate hydrates is the rate at which they form from ice or aqueous solutions, or undergo transformations to related structures. It has been established that these rates are often greatly accelerated when one guest species is inclined to form a hydrogen bond with the host lattice water molecules. Low-temperature studies of these accelerated rates suggest that quite phenomenal rates should be observed near 200 K. Here, a method of testing rates of formation of CHs at similar to 200 K is described. Complete conversion of all available water to CHs on a millisecond timescale has been observed by FTIR spectroscopy as temperatures of warm vapor mixtures drop rapidly to similar to 100 K in a cold condensation cell. That CH formation completely overrides ice nucleation and crystallization is indicative of the rapidity of the process under the new set of extreme conditions. (C) 2010 Elsevier B.V. All rights reserved.