Adsorption mechanism of poly(vinyl alcohol) on the surfaces of synthetic zeolites: sodalite, Na-P1 and Na-A

Abstract

The structure of poly(vinyl alcohol)—PVA layers adsorbed on the synthetic zeolites surfaces was determined. Three zeolites: sodalite, Na-P1 and Na-A were obtained using hydrothermal conversion of fly ash with aqueous sodium hydroxide. The effects of solution pH and zeolite type on the adsorption mechanism of the polymer were examined. The analysis of the results obtained by means of spectrophotometric and microelectrophoretic measurements as well as potentiometric titrations enabled description of interfacial behaviour of adsorbed macromolecules. It was shown that the presence of poly(vinyl alcohol) layers modifies the surface properties of applied zeolites. The evidence of this are changes in the surface charge density and zeta potential of solid particles observed in the polymer presence. Moreover the PVA chains exhibit different adsorption affinity for the examined zeolites depending mainly on the mean pore size of these aluminosilicates which is very important for penetration of internal zeolite structure by polymeric macromolecules.