Vapor-deposited alcohol glasses reveal a wide range of kinetic stability.
In situ AC nanocalorimetry was used to characterize vapor-deposited glasses of six mono- and di-alcohol molecules. Benzyl alcohol glasses with high kinetic stability and decreased heat capacity were prepared. When annealed above the glass transition temperature Tg, transformation of these glasses into the supercooled liquid took 103.4times longer than the supercooled liquid relaxation time (τα). This kinetic stability is similar to other highly stable organic glasses prepared by vapor deposition and is the first clear demonstration of an alcohol forming a stable glass. Vapor deposited glasses of five other alcohols exhibited moderate or low kinetic stability with isothermal transformation times ranging from 100.7to 102τα. This wide range of kinetic stabilities is useful for investigating the factors that control stable glass formation. Using our current results and literature data, we compare the kinetic stability of vapor deposited glasses prepared from 14 molecules and find a correlation with the value of ταat 1.25 Tg. We also observe that some vapor-deposited glasses exhibit decreased heat capacity without increased kinetic stability.
Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
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Tylinski
Institute of Physics, University of Rostock, Albert-Einstein-Str. 23-24, 18051 Rostock, Germany and Competence Centre CALOR, Faculty of Interdisciplinary Research, University of Rostock, Albert-Einstein-Str. 25, 18051 Rostock, Germany.
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Chua
Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
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Beasley
Institute of Physics, University of Rostock, Albert-Einstein-Str. 23-24, 18051 Rostock, Germany and Competence Centre CALOR, Faculty of Interdisciplinary Research, University of Rostock, Albert-Einstein-Str. 25, 18051 Rostock, Germany.
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Schick
Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
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Ediger