INTERACTIONS BETWEEN COLLOIDAL POLY(TETRAFLUOROETHYLENE) LATEX AND SODIUM POLY(STYRENESULFONATE)

The translational and rotational diffusion of poly(tetrafluoroethylene ) latex in aqueous solutions of unbound sodium poly(styrenesulfonate) were measured by dynamic light scattering. Both quantities were affect ed by the viscosity of the poly(styrenesulfonate), which was itself a function of added salt. Adjusted for viscosity, the rotational diffusi on decreased with added salt but did not depend on the polymer concent ration in the range studied. This suggests that rotational diffusion o f a probe particle can be used to sense the local ionic environment. V isual observations and static light scattering showed that salt-induce d aggregation of the latex can be prevented or reversed by small amoun ts (several milligrams per milliliter) of sodium poly(styrenesulfonate ).