Effects of poly(ethylene oxide) adsorption on the dispersion of smectites

The adsorption of polymers on clay is important in many applications. However the mechanisms of poly(ethylene oxide) (PEO) adsorption on smectite and its effect on suspension rheology are not well elucidated at present. The aim of this study was to investigate the mechanisms responsible for PEO sorption on smectite and how this impacts on dispersive behavior of smectite suspension. The results indicated that the hydrophobic interaction between CH2CH2 groups and siloxane surface is the major driven force for PEO adsorption on smectite. In addition, PEO adsorbed preferentially on the surface of low-charge smectite and the delamination of low-charge smectite in water was enhanced due to PEO adsorption presumably due to the hydrophilic ether oxygen of adsorbed PEO.