Mixing it up: Measuring diffusion in supercooled liquid solutions of methanol and ethanol at temperatures near the glass transition

Jesper Matthiesen; R. S.  Smith; B. D. Kay

Mixing it up: Measuring diffusion in supercooled liquid solutions of methanol and ethanol at temperatures near the glass transition

Jesper Matthiesen, R. S. Smith, B. D. Kay

Kemisk Institut

22 Citationer (Scopus)

Abstract

How do liquid mixtures cooled to temperatures below their freezing point behave? We address this question using nanoscale films of methanol and ethanol supercooled liquid solutions of varying composition (0-100% methanol) at temperatures near their glass transition, T_g. The permeation of Kr through these films is used to determine the diffusivities of the supercooled liquid mixtures. We find that the temperature-dependent diffusivities of the mixtures are well-fit by a Vogel-Fulcher-Tamman equation, indicating that the mixtures exhibit fragile behavior at temperatures just above their T _g. Further, for a given temperature, the composition-dependent diffusivity is well-fit by a Vignes-type equation, that is, the diffusivity of any mixture can be predicted using an exponential weighting of the pure methanol and ethanol diffusivities. These results show that deeply supercooled liquid mixtures can be used to provide valuable insight into the properties of normal liquid mixtures.

Originalsprog	Engelsk
Tidsskrift	Journal of Physical Chemistry Letters
Vol/bind	2
Sider (fra-til)	557–561
ISSN	1948-7185
Status	Udgivet - 17 mar. 2011

Citationsformater

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abstract = "How do liquid mixtures cooled to temperatures below their freezing point behave? We address this question using nanoscale films of methanol and ethanol supercooled liquid solutions of varying composition (0-100% methanol) at temperatures near their glass transition, Tg. The permeation of Kr through these films is used to determine the diffusivities of the supercooled liquid mixtures. We find that the temperature-dependent diffusivities of the mixtures are well-fit by a Vogel-Fulcher-Tamman equation, indicating that the mixtures exhibit fragile behavior at temperatures just above their T g. Further, for a given temperature, the composition-dependent diffusivity is well-fit by a Vignes-type equation, that is, the diffusivity of any mixture can be predicted using an exponential weighting of the pure methanol and ethanol diffusivities. These results show that deeply supercooled liquid mixtures can be used to provide valuable insight into the properties of normal liquid mixtures.",

author = "Jesper Matthiesen and Smith, {R. S.} and Kay, {B. D.}",

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TY - JOUR

T1 - Mixing it up: Measuring diffusion in supercooled liquid solutions of methanol and ethanol at temperatures near the glass transition

AU - Matthiesen, Jesper

AU - Smith, R. S.

AU - Kay, B. D.

PY - 2011/3/17

Y1 - 2011/3/17

N2 - How do liquid mixtures cooled to temperatures below their freezing point behave? We address this question using nanoscale films of methanol and ethanol supercooled liquid solutions of varying composition (0-100% methanol) at temperatures near their glass transition, Tg. The permeation of Kr through these films is used to determine the diffusivities of the supercooled liquid mixtures. We find that the temperature-dependent diffusivities of the mixtures are well-fit by a Vogel-Fulcher-Tamman equation, indicating that the mixtures exhibit fragile behavior at temperatures just above their T g. Further, for a given temperature, the composition-dependent diffusivity is well-fit by a Vignes-type equation, that is, the diffusivity of any mixture can be predicted using an exponential weighting of the pure methanol and ethanol diffusivities. These results show that deeply supercooled liquid mixtures can be used to provide valuable insight into the properties of normal liquid mixtures.

AB - How do liquid mixtures cooled to temperatures below their freezing point behave? We address this question using nanoscale films of methanol and ethanol supercooled liquid solutions of varying composition (0-100% methanol) at temperatures near their glass transition, Tg. The permeation of Kr through these films is used to determine the diffusivities of the supercooled liquid mixtures. We find that the temperature-dependent diffusivities of the mixtures are well-fit by a Vogel-Fulcher-Tamman equation, indicating that the mixtures exhibit fragile behavior at temperatures just above their T g. Further, for a given temperature, the composition-dependent diffusivity is well-fit by a Vignes-type equation, that is, the diffusivity of any mixture can be predicted using an exponential weighting of the pure methanol and ethanol diffusivities. These results show that deeply supercooled liquid mixtures can be used to provide valuable insight into the properties of normal liquid mixtures.

M3 - Journal article

SN - 1948-7185

VL - 2

SP - 557

EP - 561

JO - Journal of Physical Chemistry Letters

JF - Journal of Physical Chemistry Letters

ER -

Mixing it up: Measuring diffusion in supercooled liquid solutions of methanol and ethanol at temperatures near the glass transition

Abstract

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