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Ideal probe single-molecule experiments reveal the intrinsic dynamic heterogeneity of a supercooled liquid.

ABSTRACT: The concept of dynamic heterogeneity and the picture of the supercooled liquid as a mosaic of environments with distinct dynamics that interchange in time have been invoked to explain the nonexponential relaxations measured in these systems. The spatial extent and temporal persistence of these regions of distinct dynamics have remained challenging to identify. Here, single-molecule fluorescence measurements using a probe similar in size and mobility to the host o-terphenyl unambiguously reveal exponential relaxations distributed in time and space and directly demonstrate ergodicity of the system down to the glass transition temperature. In the temperature range probed, at least 200 times the structural relaxation time of the host is required to recover ensemble-averaged relaxation at every spatial region in the system.

SUBMITTER: Paeng K

PROVIDER: S-EPMC4413315 | biostudies-literature | 2015 Apr

REPOSITORIES: biostudies-literature

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Ideal probe single-molecule experiments reveal the intrinsic dynamic heterogeneity of a supercooled liquid.

Paeng Keewook K Park Heungman H Hoang Dat Tien DT Kaufman Laura J LJ

Proceedings of the National Academy of Sciences of the United States of America 20150330 16

The concept of dynamic heterogeneity and the picture of the supercooled liquid as a mosaic of environments with distinct dynamics that interchange in time have been invoked to explain the nonexponential relaxations measured in these systems. The spatial extent and temporal persistence of these regions of distinct dynamics have remained challenging to identify. Here, single-molecule fluorescence measurements using a probe similar in size and mobility to the host o-terphenyl unambiguously reveal e ...[more]

PMID: 25825739

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