ESR STUDIES OF THE DISPLACEMENT ADSORPTION BEHAVIOR OF POLY(METHYL METHACRYLATE) AND POLYSTYRENE SYSTEM AT THE SOLID-LIQUID INTERFACE

The displacement adsorption behavior of a poly(methyl methacrylate) (P MMA) and polystyrene (PS) system onto a nonporous silica surface from a carbon tetrachloride solution was studied by utilizing the ESR metho d. The fractions of train segments for these polymers were determined from ESR spectra analyses; these values were compared with those of th e individual adsorption. When PS was preadsorbed onto silica surface a nd PMMA solutions of various concentrations were added, the amount of PS desorbed from silica surface was proportional to an increase in the initial concentration of the PMMA solution; at the final concentratio n, PS was completely replaced by PMMA. This phenomenon was due to the stronger interaction of PMMA with the silica surface arising from its polar character, and the greater hydrogen bonding ability. The amount of adsorption for PMMA, which saturated the silica surface, was lower than that when adsorbed on silica surface individually. The adsorbed P MMA formed a more compressed polymer layer compared with that for the case in which PMMA was adsorbed alone. The amount and conformation of the adsorbed PMMA were affected by the presence of PS in the solution.