DETERMINATION OF CONCENTRATIONS BY ANGULAR LIGHT SCATTERING FOR TURBIDIMETRIC TITRATION OF POLYMERS

Rayleigh-Gans theory is applied to light scattering by suspensions of particles precipitated from polymer solution during turbidimetric titration. When the refractive indices of the solvent and precipitant are matched, the concentration of polymer which is precipitated is related to the scattering by a simple equation. Under conditions of angle, wavelength, and particle size such that scattering is maximized, concentration is directly proportional to scattering. The equation was tested using a solution of polystyrene in methyl ethyl ketone with isopropyl alcohol as precipitant. © 1968.