HYDRODYNAMIC LAYER THICKNESS OF POLY(ETHYLENE OXIDE) ADSORBED ON POLYSTYRENE LATEX

The adsorption of poly (ethylene oxide) onto polystyrene latex particles is investigated by means of dynamic light scattering. The data suggest that the polymer adsorption process consists of three main stages: (i) diffusion of polymer molecules to the bare surface and subsequent changes in configuration of the first layer; (ii) the formation of a dense layer until apparent full coverage; and (iii) attainment of the equilibrium layer thickness. Data on kinetics reveal the presence of an energy barrier in stages (ii) and (iii), probably due to the hindered diffusion of polymer molecules through the adsorption layer. The effect of tail configurations is investigated by comparing adsorbed polymer molecules with and without an anchor end group and it is found that adsorption of polymer molecules without anchors leads to a thicker hydrodynamic adsorption layer, in agreement with theoretical expectations.