expansion factor

in polymers
https://doi.org/10.1351/goldbook.E02270
The ratio of a dimensional characteristic of a macromolecule in a given solvent at a given temperature to the same dimensional characteristic in the θ state at the same temperature. The most frequently used expansion factors are: expansion factor of the mean-square end-to-end distance, αr=<r2><r2>0; expansion factor of the
radius of gyration
αs=<s2><s2>0;
viscosity
expansion factor αη=([η][η]θ)13 where [η] and [η]θ are the intrinsic
viscosity
in a given solvent and in the θ 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:
Purple Book, 1st ed., p. 59 [Terms] [Book]