SIZE-EXCLUSION CHROMATOGRAPHIC AND VISCOMETRIC STUDY OF POLYMER-SOLUTIONS CONTAINING NICOTINE OR SILICIC-ACID

Preferential interactions of polymers with low-molecular-mass compounds were investigated regarding mainly the preferential solvation parameter and the intrinsic viscosity of ternary polymer solutions. Well characterized poly(vinylpyrrolidone) and poly(4-vinylpyridine) as macromolecular components in the presence of pure water or buffered solutions of nicotine or silicic acid served to formulate several ternary systems. Measurements included size-exclusion chromatography (SEC) and viscometry (off-line) at the appropriate concentration ranges, in order to obtain a linear response of the SEC detector and to describe the concentration dependence of the reduced viscosity by means of the Huggins equation for dilute polymer solutions. The former technique allows the so-called vacant peak to be attained, closely related to the preferential solvation parameter, which was directly monitored by means of a refractive index detector. Numerical evaluation of the preferential solvation parameter and intrinsic viscosity was used to account for overall interactions between linear vinyl polymers and nicotine and silicic acid as precursors of toxic agents.