Stabilizing Na-bentonite by Poly(Diallyl Dimethyl Ammonium Chloride) Adsorption

Abstract

Clay minerals have been modified by polymers for different applications. The polymer addition affects not only the surface properties
but also the rheological properties and the stability of the clay-polymer suspension as a whole. In the current study, the electro-chemical properties of bentonite particles in presence of poly diallyl dimethyl ammonium chloride (PDDACl) were investigated. These
properties were characterized by as zeta potential, adsorption isotherm, Fourier transform infrared (FTIR) and the apparent viscosity
at different solid percent. The results indicated that the viscosity of the bentonite-PDDACl suspension not only increases by raising the
polymer concentration but also by increasing solids %. Adsorption of PDDACl polymer increases the positivity of bentonite surface
as a function of polymer concentration, which could be explained mainly by electrostatic interaction of deficient metal ions at the
octahedral sheets of bentonite with the cationic head group of the polymer. The PDDACl adsorption isotherm on bentonite fits more
probably Langmuir than Freundlich isotherm