학술논문
The complex behavior of the "simplest" liquid: Breakdown of density scaling in tetramethyl tetraphenyl trisiloxane.
Document Type
Article
Source
Subject
*LIQUID density
*DIELECTRIC relaxation
*SILOXANES
*DIELECTRIC measurements
*CHEMICAL structure
*SUPERCOOLED liquids
*BEHAVIOR
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Language
ISSN
0021-9606
Abstract
Dielectric relaxation measurements, in combination with density determinations, on tetramethyl tetraphenyl trisiloxane (DC704) over an unusually broad range of temperatures and pressures revealed a state-point dependency in its density scaling exponent. This is the first unambiguous experimental demonstration of a breakdown of density scaling in a nonassociated glass-forming material, and unanticipated for DC704, among the "simplest" of liquids, having a constant breadth of the relaxation dispersion and a Prigogine-Defay ratio near unity characteristic of approximate single-parameter systems. We speculate that the anomalous behavior has origins in the large value of its scaling exponent and relative flexibility of the chemical structure. [ABSTRACT FROM AUTHOR]