Diluent effects on the Debye-type dielectric relaxation in viscous monohydroxy alcohols

Li Min Wang, Shervin Shahriari, Ranko Richert

Research output: Contribution to journalArticle

38 Citations (Scopus)

Abstract

With the recognition that the Debye-type dielectric relaxation of liquid monohydroxy alcohols does not reflect the structural relaxation dynamics associated with the viscous flow and the glass transition, its behavior upon dilution is expected to differ from that of real α-processes. We have investigated the Debye-type dielectric relaxation of binary alcohol/alkane mixtures across the entire concentration range in the supercooled regimes. The focus is on 2-ethyl-1-hexanol in two nonpolar liquids, 3-methylpentane and squalane, which are more fluid and more viscous than the alcohol, respectively. The Debye relaxation is found to occur only for alcohol mole fractions x > 0.2 and is always accompanied by a non-Debye relaxation originating from the alcohol component. Prior to its complete disappearance, the Debye relaxation is subject to broadening. We observe that the Debye dynamics of 2-ethyl-1-hexanol is accelerated in the more fluid 3-methylpentane, while the more viscous squalane leads to longer Debye relaxation times. The present experiments also provide evidence that the breakdown of the Debye relaxation amplitude does not imply the absence of hydrogen-bonded structures.

Original languageEnglish (US)
Pages (from-to)23255-23262
Number of pages8
JournalJournal of Physical Chemistry B
Volume109
Issue number49
DOIs
StatePublished - Dec 15 2005

Fingerprint

diluents
Dielectric relaxation
alcohols
Alcohols
Structural relaxation
Alkanes
Fluids
Liquids
Viscous flow
Relaxation time
Paraffins
Dilution
Glass transition
Hydrogen
fluids
viscous flow
liquids
alkanes
dilution
breakdown

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry

Cite this

Diluent effects on the Debye-type dielectric relaxation in viscous monohydroxy alcohols. / Wang, Li Min; Shahriari, Shervin; Richert, Ranko.

In: Journal of Physical Chemistry B, Vol. 109, No. 49, 15.12.2005, p. 23255-23262.

Research output: Contribution to journalArticle

@article{e39d70808f344b7092a49a87cdf2af46,
title = "Diluent effects on the Debye-type dielectric relaxation in viscous monohydroxy alcohols",
abstract = "With the recognition that the Debye-type dielectric relaxation of liquid monohydroxy alcohols does not reflect the structural relaxation dynamics associated with the viscous flow and the glass transition, its behavior upon dilution is expected to differ from that of real α-processes. We have investigated the Debye-type dielectric relaxation of binary alcohol/alkane mixtures across the entire concentration range in the supercooled regimes. The focus is on 2-ethyl-1-hexanol in two nonpolar liquids, 3-methylpentane and squalane, which are more fluid and more viscous than the alcohol, respectively. The Debye relaxation is found to occur only for alcohol mole fractions x > 0.2 and is always accompanied by a non-Debye relaxation originating from the alcohol component. Prior to its complete disappearance, the Debye relaxation is subject to broadening. We observe that the Debye dynamics of 2-ethyl-1-hexanol is accelerated in the more fluid 3-methylpentane, while the more viscous squalane leads to longer Debye relaxation times. The present experiments also provide evidence that the breakdown of the Debye relaxation amplitude does not imply the absence of hydrogen-bonded structures.",
author = "Wang, {Li Min} and Shervin Shahriari and Ranko Richert",
year = "2005",
month = "12",
day = "15",
doi = "10.1021/jp054542k",
language = "English (US)",
volume = "109",
pages = "23255--23262",
journal = "Journal of Physical Chemistry B Materials",
issn = "1520-6106",
publisher = "American Chemical Society",
number = "49",

}

TY - JOUR

T1 - Diluent effects on the Debye-type dielectric relaxation in viscous monohydroxy alcohols

AU - Wang, Li Min

AU - Shahriari, Shervin

AU - Richert, Ranko

PY - 2005/12/15

Y1 - 2005/12/15

N2 - With the recognition that the Debye-type dielectric relaxation of liquid monohydroxy alcohols does not reflect the structural relaxation dynamics associated with the viscous flow and the glass transition, its behavior upon dilution is expected to differ from that of real α-processes. We have investigated the Debye-type dielectric relaxation of binary alcohol/alkane mixtures across the entire concentration range in the supercooled regimes. The focus is on 2-ethyl-1-hexanol in two nonpolar liquids, 3-methylpentane and squalane, which are more fluid and more viscous than the alcohol, respectively. The Debye relaxation is found to occur only for alcohol mole fractions x > 0.2 and is always accompanied by a non-Debye relaxation originating from the alcohol component. Prior to its complete disappearance, the Debye relaxation is subject to broadening. We observe that the Debye dynamics of 2-ethyl-1-hexanol is accelerated in the more fluid 3-methylpentane, while the more viscous squalane leads to longer Debye relaxation times. The present experiments also provide evidence that the breakdown of the Debye relaxation amplitude does not imply the absence of hydrogen-bonded structures.

AB - With the recognition that the Debye-type dielectric relaxation of liquid monohydroxy alcohols does not reflect the structural relaxation dynamics associated with the viscous flow and the glass transition, its behavior upon dilution is expected to differ from that of real α-processes. We have investigated the Debye-type dielectric relaxation of binary alcohol/alkane mixtures across the entire concentration range in the supercooled regimes. The focus is on 2-ethyl-1-hexanol in two nonpolar liquids, 3-methylpentane and squalane, which are more fluid and more viscous than the alcohol, respectively. The Debye relaxation is found to occur only for alcohol mole fractions x > 0.2 and is always accompanied by a non-Debye relaxation originating from the alcohol component. Prior to its complete disappearance, the Debye relaxation is subject to broadening. We observe that the Debye dynamics of 2-ethyl-1-hexanol is accelerated in the more fluid 3-methylpentane, while the more viscous squalane leads to longer Debye relaxation times. The present experiments also provide evidence that the breakdown of the Debye relaxation amplitude does not imply the absence of hydrogen-bonded structures.

UR - http://www.scopus.com/inward/record.url?scp=30544443558&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=30544443558&partnerID=8YFLogxK

U2 - 10.1021/jp054542k

DO - 10.1021/jp054542k

M3 - Article

VL - 109

SP - 23255

EP - 23262

JO - Journal of Physical Chemistry B Materials

JF - Journal of Physical Chemistry B Materials

SN - 1520-6106

IS - 49

ER -