This Letter reports the first experimental evidence that solutions of linear flexible polymers are characterized by a concentration-dependent universal length which is easily scaled to be independent of molecular weight $M(3\mathrm{}\times {10}^5<~M<~2.6\times {10}^7)$ and of solvent quality. It is also found that the product of $M$ and the derivative of the osmotic pressure $\pi$ with respect to concentration $c$, $M{\left(\frac{\partial \pi }{\partial c}\right)}_T$, is universal and independent of solvent quality or $M$.

• Received 13 June 1983

DOI:https://doi.org/10.1103/PhysRevLett.51.1183