Experimental verification of renormalization group theoretical results for dilute macromolecular solutions. I. Light scattering data for polystyrene in solvents differing in thermodynamic quality

Abstract

AbstractStatic and dynamic molecular properties are obtained from simultaneous elastic and quasielastic light scattering experiments for nine narrowly distributed polystyrene fractions in nine solvents covering the cross‐over region from theta to good‐solvent conditions. This set of consistent experimental data is compared with theoretical predictions of two renormalization group theories: the first‐order ϵ‐expansion calculations of Oono et al. and second‐order calculations within the “renormalized two‐parameter” theory of Douglas and Freed. Static properties (the penetration function) are found to be exactly described by the ϵ2‐order model, while dynamic behavior seems to be in better accord with Oono's ϵ1‐order calculations. No evidence of draining effects is detected. Solutions with benzene (and partially with toluene) exhibited atypical, nonuniversal behavior. Some features of static and dynamic exponents behavior in the crossover region are also discussed and compared with previously published theoretical predictions.