ADSORPTION AND THIN-FILM FORMATION OF DIBLOCK AND TRIBLOCK COPOLYMERS

The adsorption of diblock and triblock copolymers of styrene and ethyl ene oxide, P(S-b-EO), from dilute solution is studied by ellipsometry. The copolymers consist of short poly(ethylene oxide) blocks which ads orb onto a silicon wafer and longer polystyrene blocks which do not ad sorb on the substrate under the conditions employed, but dangle in sol ution. Surface coverage is monitored as a function of time, and differ ent time regimes are resolved. The equilibrium surface coverage is dis cussed with respect to scaling models where the ratio of the block len gths determines the adsorption behaviour. Also, dry films of adsorbed copolymers are analysed by ellipsometry and X-ray reflectometry.