Sublimation Freeze-Drying without Vacuum

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Science  11 Sep 1959:
Vol. 130, Issue 3376, pp. 628-629
DOI: 10.1126/science.130.3376.628


Analysis of the freeze-drying procedure shows that the passage of water vapor from the drying boundary through the dried shell is facilitated primarily by the vapor pressure gradient rather than by the absolute pressure of the system. This is experimentally confirmed, and a device for freeze-drying at atmospheric pressure is described.