Parallel versus Perpendicular Lamellar-within-Lamellar Self-Assembly of A-b-(B-b-A)_n-b~C Ternary Multiblock Copolymer Melts

摘要

Different types of lamellar-within-lamellar structure formations in A-b-(B-b-A)_n-b-C terpolymer melts, with a volume fraction of components A, B, and C in the ratio of 1:1:2, are analyzed in the strong segregation limit using a simple theoretical approach. We consider the lamellar, parallel lamellar-within-lamellar, and perpendicular lamellar-within-lamellar self-assembled states. The influence of the copolymer chain length N, the value of the Flory-Huggins interaction parameters X_(AB), X_(AC), and X_(BC), and the number of blocks n in the AB multiblock chain on the phase behavior is discussed. We show that in the limiting case of n 1, the perpendicular lamellar-within-lamellar state becomes stable when the interaction parameters satisfy the relation 0