| Issue |
J. Phys. II France
Volume 6, Number 5, May 1996
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|---|---|---|
| Page(s) | 697 - 711 | |
| DOI | https://doi.org/10.1051/jp2:1996206 | |
J. Phys. II France 6 (1996) 697-711
Analysis of Relaxation Functions Characterized by a Broad Monomodal Relaxation Time Distribution
Taco Nicolai1, Jean Christophe Gimel1 and Robert Johnsen21 Laboratoire de Physico Chimie Macromoléculaire, Faculté des Sciences, Université du Maine, 72017 le Mans Cedex, France
2 Department of Physical Chemistry, University of Uppsala, 75121 Uppsala, Sweden
(Received 10 October 1995, received in final form 26 December 1995, accepted 2 February 1996)
Abstract
We demonstrate the advantage of using the so-called generalized exponential (GEX) function for the
analysis of relaxation functions characterized by a monomodal broad relaxation time distribution. We
give a number of characteristics of this function and compare it to two functions that are currently
widely for this type of analysis: the Kohlraush-Williams-Watt and the Havriliak-Negami functions.
The main advantages of the GEX-function are that it can be used easily both in the time and the
frequency domain, and that it has a relatively simple expression for the corresponding relaxation
time distribution. Three important applications are discussed: the glass transition dynamics, and
the relaxation of concentration fluctuations in dilute and concentrated solutions of broad
distributions of selfsimilar particles. In the latter two cases the relation between the parameters
of the GEX-function and the molecular characteristics of the solutions is made explicit.
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