Zeta Potential of Tropical Soil in Presence of Polyvinyl Alcohol

Abstract

The focus of this research is to study the influence of polyvinyl alcohol (PVA) adsorption on the zeta potential properties of two tropical soil namely peat, and kaolinite. Two different PVA species were used, partially hydrolyzed (PVA-T) as well as fully hydrolyzed (PVA-F). As results, adding the PVA species into the suspended colloids led to an increase of zeta potential in their surfaces, contrary to measuring done in water. The zeta potential of the Peat soil varied from 25.26 to -95.1 mV, according to the PVA type and concentration. Kaolinite, however, showed zeta potential varied from +32.4 to -161.78. Negative charge in both peat and kaolinite soils were highly pH dependent and their surface charge dropped to zero at pH 3.1 to 3.4. Using PVA cause a significant reduction in isoelectric point (IEP) of soil samples to about 1.9 for peat and 2.1 for kaolinite. PVA-F enhanced the negative zeta potential than PVA-T. However, increasing of zeta potential in negative sign with increasing degree of polymerization can be observed in both PVA-T and PVA-F samples.