Mixed supercrystalline structures in mixtures of ABC-triblock and AB(BC)-diblock copolymers, 1 - Lamellar structures in bicomponent mixtures

The theory of lamellar superstructures in binary mixtures of AB diblock and linear ABC triblock copolymers under the condition of strong segregation b etween chemically different blocks is developed. This system is considered using Alexander-de Gennes (box-model) and self-consistent field (SCF) model s. The formation of a mixed lamellar superstructure comprising both mixture components is proved. It is shown that a mixed lamella may be the only typ e of lamellae in the mixture, or it may coexist with pure diblock lamellae, depending on the mixture composition, local characteristics of blocks (thi ckness and Kuhn segment length), and surface tension coefficients at the A/ B and B/C interfaces. Preliminary experimental results provide support of t hese theoretical estimations. The formation of mixed lamellae in a mixture of linear ABC and branched (AB)(2)C block copolymers is also considered.