Molar Mass, Radius of Gyration and Second Virial Coefficient from new Static Light Scattering Equations for Dilute Solutions: Application to 21 (Macro)molecules

Abstract

New static light scattering (SLS) equations for dilute binary solutions are derived. Contrarily to the usual SLS equations [Carr-Zimm (CZ)], the new equations have no need for the experimental absolute Rayleigh ratio of a reference liquid and solely rely on the ratio of scattered intensities of solutions and solvent. The new equations, which are based on polarizability equations, take into account the usual refractive index increment partial differential n/partial differential rho(2) complemented by the solvent specific polarizability and a term proportional to the slope of the solution density rho versus the solute mass concentration rho(2) (density increment). Then all the equations are applied to 21 (macro)molecules with a wide range of molar mass (0.2<M<8000 kg mol(-1)). On the studied dataset with M<200 kg mol(-1), the new equations clearly achieve a better agreement with supplier M values. For macromolecules (M>500 kg mol(-1)), for which the scattered intensity is no longer independent of the scattering angle, the new equations give the same value of the radius of gyration as the CZ equation and consistent values of the second virial coefficient.

Surface Behavior of BSA/Water/Carbohydrate Systems from Molecular Polarizability Measurements

“…For simplicity, we represented the values of frequencies in terms of its complementary wavenumber. The dynamic mean electronic molecular polarizability of BSA α 2(ν) e in water and in each carbohydrate–water solution was estimated using the data and the refractometric equation of Proutiére, , which reads where and N is Avogadro’s number.…”