Adsorption of Poly (ethylene oxide) onto Silica at Different Solids Loadings

The adsorption of poly (ethylene oxide) (PEO) of 7,500 MW, a hydrogen bonding polymer, onto the surface of monodisperse colloidal silica particles was investigated as a function of volume fraction of solids. Adsorption studies revealed the presence of two plateaus, which was attributed to a change in conformation from a flat, "pancake" type, to a more elongated "brush" type conformation of the adsorbed polymer, where the terminal hydroxyl groups remained bound to the silica surface. Adsorption studies also revealed that, within the concentration range studied, there was no effect upon PEO adsorption as a function of volumefraction.