Static wetting behaviour of diblock copolymers

(Received 23 February 1993, revised and accepted 16 July 1993)

Abstract
Thin liquid films of ordered diblock copolymers deposited on a solid substrate form a multilayer stacking parallel to the solid surface. A multilayer with a finite extend can be stable, metastable, or unstable, depending on the relative values of the surface energies of the various interfaces. The spreading parameter and chemical potential of a n-layer are derived, and used for classifying all possible situations. It is shown that only mono- and bilayers can be stable, and that non-wetting multilayers are subjected to a long-time piling up instability, leading in practice to the formation of characteristic ziggourat-like structures.