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Type II Clathrate Hydrate Formation in Cometary Ice Analogs in Vacuo

Published online by Cambridge University Press:  07 August 2017

D. F. Blake
Affiliation:
MS 239-4 NASA/Ames Research Center Moffett Field, CA 94035 - USA
L. Allamandola
Affiliation:
MS 239-4 NASA/Ames Research Center Moffett Field, CA 94035 - USA
S. Sandford
Affiliation:
MS 239-4 NASA/Ames Research Center Moffett Field, CA 94035 - USA
D. Hudgins
Affiliation:
MS 239-4 NASA/Ames Research Center Moffett Field, CA 94035 - USA
F. Freund
Affiliation:
Dept. of Physics San Jose State University San Jose, CA 95192 USA

Abstract

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Clathrate Hydrates can be formed under high vacuum conditions by annealing vapor-deposited amorphous ices of the appropriate composition. When astrophysically significant H2O:CH3OH ices are deposited and annealed, Type II Clathrate Hydrates are formed which can hold up to 6 mole % large guest molecules such as methanol and 12 mole % small guest molecules such as CO2 and CO. The solid state transformation of amorphous mixed molecular ice into crystalline clathrate hydrate and its sublimation at higher temperatures may serve to explain heretofore anomalous mechanical and gas release properties observed in cometary ices and laboratory ice analog experiments.

Type
Solar System
Copyright
Copyright © Kluwer 1992 

References

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