On the morphology of a lamellar triblock copolymer film

X-ray and neutron reflectivity are used to study the morphology of a triblock copolymer of d-poly(styrene) and poly(2-vinylpyridine) in the form P2VP ₃₀-dPS ₆₀-P2VP ₃₀ deposited as a film on a silicon wafer. Microphase separation leads to a lamellar film which is strongly quantized in layers of about 300 Å each and with P2VP at the silicon substrate. The confinement of the polymer ends to the same plane leads for the top layer to a "looping" of the polymer, so that the middle PS part can still wet the air interface completely.