The Spectrophotometric Investigation of Nonionic Polymer Adsorption (Polyethylene Glycol (PEG), Polyethylene Oxide (PEO) and Polyvinyl Alcohol (PVA)) Influence on the Alumina Suspension Stability – Effects of Polymer Type, its Molecular Weight and Solution pH

Abstract The effect of nonionic polymer adsorption on the stability of alumina (Al2O3) in the pH range 3–9 was examined. The influences of polymer type and its molecular weight, as well as solution pH, were studied. The following macromolecular substances were used: polyethylene glycol (PEG), polyethylene oxide (PEO) and polyvinyl alcohol (PVA). The spectrophotometry method was applied to obtain the stability curves (dependence of suspension absorbance vs. time). The obtained results indicate that the addition of the polymer influences alumina suspension stability. The addition of the polymer at pH 3 improves the stability conditions of investigated systems. At pH = 6 the decrease of Al2O3 suspension stability (except PEG 2 000) was obtained. On the other hand, at pH 9 the presence of polymer improves the stability properties of the alumina. The higher the molecular weight of the polymer, the more pronounced effects were observed. Moreover, adsorption of polyvinyl alcohol whose macromolecules contain ionizable acetate groups causes greater changes in alumina suspension stability in comparison to the systems containing polyethylene glycol and polyethylene oxide. Keywords: Polyvinyl alcoholpolyethylene glycolpolyethylene oxidealuminapolymer conformationsuspension stability