The ratio of a dimensional characteristic of a macromolecule in a given solvent at
a given temperature to the same dimensional characteristic in the

state at the same temperature. The most frequently used expansion factors are: expansion
factor of the mean-square end-to-end distance,

;
expansion factor of the
radius of gyration
;
viscosity expansion factor

where

and

are the intrinsic
viscosity in a given solvent and in the

state at the same temperature, respectively. Expansion factors defined by different
dimensional characteristics are not exactly equal, nor need they have a constant ratio
as a function of
relative molecular mass.
Source:
Cite as:
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by
A. D. McNaught and A.Wilkinson. Blackwell Scientific Publications, Oxford (1997).
XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic,
J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8.
https://doi.org/10.1351/goldbook.