Competitive adsorption of polyelectrolytes: A size exclusion chromatographic study

Competitive adsorption of sodium polystyrene sulfonate (PSS), mol wt 4000 and 1,200,000 on hematite, was studied using size exclusion chromatography. In the absence of electrolyte, short-term kinetics led to higher adsorption of 4000 mol wt. No displacement effects were observed due to electrostatic repulsion between polymer segments. At 0.1 kmole/m3 NaCl, 1,200,000 PSS displaced adsorbed 4000 PSS leading to isotherms similar to those of nonionic polymers.