Does Equilibrium Polymerization Describe the Dynamic Heterogeneity of Glass-Forming Liquids?

Published

October 13, 2006

Author(s)

Jack F. Douglas, J Dudowicz, Karl Freed

Abstract

We examine whether the `dynamic heterogeneities' of glass-forming liquids can be described by equilibrium polymerization. This correspondence is first checked by demonstrating a resemblance between the T dependence of the configurational entropy s in both the theory of equilibrium polymerization and the generalized entropy theory of glass-formation in polymer melts. Moreover, the multiple characteristic temperatures of glass-formation are shown to have analogs in equilibrium polymerization, supporting the contention that both processes are varieties of rounded thermodynamic transitions.We also find the average degree of polymerization varies in near inverse proportionality to s, consistent with a basic premise of Adam-Gibbs. The identification of the CRR with equilibrium polymers is further supported by simulations for a variety of glass-forming liquids that verify the existence of string-like clusters exhibiting collective particle motion and having an exponential length distribution, in accord with the predictions of equilibrium polymerization theory.

Citation

Journal of Chemical Physics

Volume

125

Pub Type

Journals

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Keywords

entropy theory of glass formation, equilibrium polymerization entropy, rounded thermodynamic transition, self-assembly, strings

Citation

Douglas, J. , Dudowicz, J. and Freed, K. (2006), Does Equilibrium Polymerization Describe the Dynamic Heterogeneity of Glass-Forming Liquids?, Journal of Chemical Physics, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=852631 (Accessed December 26, 2024)