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 propertiesbut 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. Theseproperties were characterized by as zeta potential, adsorption isotherm, Fourier transform infrared (FTIR) and the apparent viscosityat different solid percent. The results indicated that the viscosity of the bentonite-PDDACl suspension not only increases by raising thepolymer concentration but also by increasing solids %. Adsorption of PDDACl polymer increases the positivity of bentonite surfaceas a function of polymer concentration, which could be explained mainly by electrostatic interaction of deficient metal ions at theoctahedral sheets of bentonite with the cationic head group of the polymer. The PDDACl adsorption isotherm on bentonite fits moreprobably Langmuir than Freundlich isotherm