Physical aging of molecular glasses studied by a device allowing for rapid thermal equilibration

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Resumé

Aging to the equilibrium liquid state of organic glasses is studied. The glasses were prepared by cooling the liquid to temperatures just below the glass transition. Aging following a temperature jump was studied by measuring the dielectric loss at a fixed frequency using a microregulator in which temperature is controlled by means of a Peltier element. Compared to conventional equipment, the new device adds almost two orders of magnitude to the span of observable aging times. Data for the following five glass-forming liquids are presented: dibutyl phthalate, diethyl phthalate, 2,3-epoxy propyl-phenyl-ether, 5-polyphenyl-ether, and triphenyl phosphite. The aging data were analyzed using the Tool–Narayanaswamy formalism. The following features are found for all five liquids: (1) The liquid has an “internal clock,” a fact that is established by showing that aging is controlled by the same material time that controls the dielectric properties. (2) There are no so-called expansion gaps between the long-time limits of the relaxation rates following up and down jumps to the same temperature. (3) At long times, the structural relaxation appears to follow a simple exponential decay. (4) For small temperature steps, the rate of the long-time exponential structural relaxation is identical to that of the long-time decay of the dipole autocorrelation function.
OriginalsprogEngelsk
TidsskriftJournal of Chemical Physics
Vol/bind133
Sider (fra-til)174514-01 - 174514-14
Antal sider14
ISSN0021-9606
DOI
StatusUdgivet - 2010

Citer dette

@article{d8f89d7b135e470d85a210237af96931,
title = "Physical aging of molecular glasses studied by a device allowing for rapid thermal equilibration",
abstract = "Aging to the equilibrium liquid state of organic glasses is studied. The glasses were prepared by cooling the liquid to temperatures just below the glass transition. Aging following a temperature jump was studied by measuring the dielectric loss at a fixed frequency using a microregulator in which temperature is controlled by means of a Peltier element. Compared to conventional equipment, the new device adds almost two orders of magnitude to the span of observable aging times. Data for the following five glass-forming liquids are presented: dibutyl phthalate, diethyl phthalate, 2,3-epoxy propyl-phenyl-ether, 5-polyphenyl-ether, and triphenyl phosphite. The aging data were analyzed using the Tool–Narayanaswamy formalism. The following features are found for all five liquids: (1) The liquid has an “internal clock,” a fact that is established by showing that aging is controlled by the same material time that controls the dielectric properties. (2) There are no so-called expansion gaps between the long-time limits of the relaxation rates following up and down jumps to the same temperature. (3) At long times, the structural relaxation appears to follow a simple exponential decay. (4) For small temperature steps, the rate of the long-time exponential structural relaxation is identical to that of the long-time decay of the dipole autocorrelation function.",
keywords = "ageing, cooling, dielectric losses, glass, glass transition, rapid thermal processing",
author = "Tina Hecksher and Olsen, {Niels Boye} and Kristine Niss and Dyre, {J. C.}",
year = "2010",
doi = "10.1063/1.3487646",
language = "English",
volume = "133",
pages = "174514--01 -- 174514--14",
journal = "Journal of Chemical Physics",
issn = "0021-9606",
publisher = "American Institute of Physics",

}

Physical aging of molecular glasses studied by a device allowing for rapid thermal equilibration. / Hecksher, Tina; Olsen, Niels Boye; Niss, Kristine; Dyre, J. C.

I: Journal of Chemical Physics, Bind 133, 2010, s. 174514-01 - 174514-14.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningpeer review

TY - JOUR

T1 - Physical aging of molecular glasses studied by a device allowing for rapid thermal equilibration

AU - Hecksher, Tina

AU - Olsen, Niels Boye

AU - Niss, Kristine

AU - Dyre, J. C.

PY - 2010

Y1 - 2010

N2 - Aging to the equilibrium liquid state of organic glasses is studied. The glasses were prepared by cooling the liquid to temperatures just below the glass transition. Aging following a temperature jump was studied by measuring the dielectric loss at a fixed frequency using a microregulator in which temperature is controlled by means of a Peltier element. Compared to conventional equipment, the new device adds almost two orders of magnitude to the span of observable aging times. Data for the following five glass-forming liquids are presented: dibutyl phthalate, diethyl phthalate, 2,3-epoxy propyl-phenyl-ether, 5-polyphenyl-ether, and triphenyl phosphite. The aging data were analyzed using the Tool–Narayanaswamy formalism. The following features are found for all five liquids: (1) The liquid has an “internal clock,” a fact that is established by showing that aging is controlled by the same material time that controls the dielectric properties. (2) There are no so-called expansion gaps between the long-time limits of the relaxation rates following up and down jumps to the same temperature. (3) At long times, the structural relaxation appears to follow a simple exponential decay. (4) For small temperature steps, the rate of the long-time exponential structural relaxation is identical to that of the long-time decay of the dipole autocorrelation function.

AB - Aging to the equilibrium liquid state of organic glasses is studied. The glasses were prepared by cooling the liquid to temperatures just below the glass transition. Aging following a temperature jump was studied by measuring the dielectric loss at a fixed frequency using a microregulator in which temperature is controlled by means of a Peltier element. Compared to conventional equipment, the new device adds almost two orders of magnitude to the span of observable aging times. Data for the following five glass-forming liquids are presented: dibutyl phthalate, diethyl phthalate, 2,3-epoxy propyl-phenyl-ether, 5-polyphenyl-ether, and triphenyl phosphite. The aging data were analyzed using the Tool–Narayanaswamy formalism. The following features are found for all five liquids: (1) The liquid has an “internal clock,” a fact that is established by showing that aging is controlled by the same material time that controls the dielectric properties. (2) There are no so-called expansion gaps between the long-time limits of the relaxation rates following up and down jumps to the same temperature. (3) At long times, the structural relaxation appears to follow a simple exponential decay. (4) For small temperature steps, the rate of the long-time exponential structural relaxation is identical to that of the long-time decay of the dipole autocorrelation function.

KW - ageing

KW - cooling

KW - dielectric losses

KW - glass

KW - glass transition

KW - rapid thermal processing

U2 - 10.1063/1.3487646

DO - 10.1063/1.3487646

M3 - Journal article

VL - 133

SP - 174514-01 - 174514-14

JO - Journal of Chemical Physics

JF - Journal of Chemical Physics

SN - 0021-9606

ER -