The adsorption of polyvinylpyrrolidone on kaolinite saturated with sodium chloride

The adsorption of two different molecular weights of polyvinylpyrrolidone ( PVP) (M-W=44,000 and M-W=360,000 g mol(-1)) from water on kaolinite saturat ed with sodium chloride has been studied. The adsorption of PVP increases s lowly as temperature increases. The adsorption of PVP on the kaolinite was studied by considering Fourier transform infrared (FTIR) spectra, X-ray dif fraction patterns, and dielectric constants. During the adsorption process, PVP interacts with saturating sodium cations and possibly forces some of t hem onto the edges of the kaolinite; thus, the dielectric constant of satur ated kaolinite is reduced after PVP adsorption. (C) 2001 Academic Press.