## 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 $$\unicode[Times]{x3B8}$$ state at the same temperature. The most frequently used expansion factors are: expansion factor of the mean-square end-to-end distance, $$\alpha _{r} = \sqrt{\frac{ < r^{2} > }{< r^{2} >_{0}}}$$; expansion factor of the @[email protected] $$\alpha _{s} = \sqrt{\frac{ < s^{2} > }{ < s^{2} >_{0}}}$$; @[email protected] expansion factor $$\alpha _{\eta } = (\frac{\left[\eta \right]}{\left[\eta \right]_{\unicode[Times]{x3B8} }})^{\frac{1}{3}}$$ where $$[\eta]$$ and $$[\eta]_{\unicode[Times]{x3B8}}$$ are the intrinsic @[email protected] in a given solvent and in the $$\unicode[Times]{x3B8}$$ 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 @[email protected]
Source:
Purple Book, 1st ed., p. 59 [Terms] [Book]