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Theoretical and experimental models on viscosity: I. Glycerol
Salvatore Magazù1, Federica Migliardo, Nicolay P Malomuzh
1Dipartimento di Fisica, Università di Messina, P.O. Box 55, I-98166 Messina, Italy. smagazu@unime.it
The Journal of Physical Chemistry. B
|July 28, 2007
Summary
This study links glycerol
Area of Science:
- Materials Science
- Physical Chemistry
- Polymer Science
Background:
- Fragility is a key property of viscous liquids, influencing their structural relaxation dynamics.
- Understanding the molecular basis of fragility is crucial for predicting material behavior.
- Glycerol serves as a model system for studying liquid fragility due to its hydrogen-bonding network.
Purpose of the Study:
- To establish a quantitative link between macroscopic fragility and molecular-level properties in glycerol.
- To explore the relationship between the macroscopic fragility parameter (m) and the average number of hydrogen bonds per molecule.
- To discuss the connection between macroscopic and microscopic definitions of fragility, incorporating atomic dynamics.
Main Methods:
- Calculation of the macroscopic fragility parameter (m) from viscosity data.
- Estimation of the average number of hydrogen bonds per molecule.
- Analysis of the temperature dependence of atomic mean square displacement.
Main Results:
- A direct correlation was found between the macroscopic fragility parameter (m) and the average number of hydrogen bonds per glycerol molecule.
- The study provides insights into how molecular interactions govern the macroscopic flow behavior of liquids.
- The temperature dependence of atomic motion is shown to be relevant to microscopic fragility definitions.
Conclusions:
- The macroscopic fragility of glycerol is strongly influenced by its hydrogen-bonding network.
- A unified understanding of liquid fragility can be achieved by connecting macroscopic and microscopic perspectives.
- This work contributes to the fundamental understanding of glass-forming liquids and their dynamics.
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