FORCES BETWEEN SURFACES WITH ADSORBED POLYMERS .3. THETA-SOLVENT - CALCULATIONS AND COMPARISON WITH EXPERIMENT

The adsorption of polymers onto a surface from a θ solvent is treated in terms of a mean- field model based on a Cahn-de Gennes approach. In particular, we calculate the forces between two such polymer bearing surfaces and compare our results in some detail with available experimental data on force profiles between mica surfaces bearing adsorbed polymer near the θ temperature. All parameters in our model may be estimated from experiment. The predicted force profiles are in very good qualitative agreement with the experimental data, though the absolute spatial and energy scales are smaller for the calculated profiles by factors of ca. 4 and 2.5 relative to experiment. The causes of this discrepancy and possible improvements to the model are considered. © 1990, American Chemical Society. All rights reserved.