Colloidal Stability by Adsorption of Ni²⁺ or Fe³⁺ Cations on Hairy Latex Particles

Abstract

Polymer latexes have many industrial applications and are considered as models of colloids. The DLVO theory has been widely used to describe the colloidal stability. The adsorption of Ni²⁺ and Fe³⁺ cations on polyvinyl acetate latex particles in the presence of counterions, and the colloidal stability of the system were studied. The obtained results indicate that Ni²⁺ or Fe³⁺ cations were adsorbed on the latex particles’ hairy layers, which also helped to prevent latex coagulation. The stability of the PVAc latex within highly concentrated ionic media shows a deviation from the behavior described by the classical DLVO theory.

Keywords:

• Cations adsorption
• Langmuir isotherm
• polyvinyl acetate latex

Acknowledgments

The authors would like to thank FAPESP for financial support, Prof. Dr. F. Galembeck for the use of equipment and infrastructure, and Mrs. M.C.V. da Silva for her assistance in obtaining the SEM images.

Notes

^a Measurements performed in presence of 1.0 × 10⁻³ KCl.