Are simple power laws adequate for the description of ternary polymer solutions? An analysis of special experimental situations

The renormalization group is used to analyse special mental situations close to scaling limits, especially scattering experiments under optical θ-conditions or in a solvent isorefractive to one polymer component. A modification of the optical θ-condition, based on renormalization theory is suggested and osmotic pressure compensation experiments equivalent to the scattering experiments mentioned above are analyzed. It is found that in general a simple evaluation using power law scaling is not justified and that Flory's χ 12 -parameter in general is not the appropriate quantity for an analysis of the experiments