Microphase-Separation Behavior of Triblock Copolymer Melts. Comparison with Diblock Copolymer Melts

Polydispersity-induced macrophase separation in diblock copolymer melts.

The effect of A-block polydispersity on the phase behavior of AB-diblock copolymer melts is examined using a complete self-consistent field theory treatment that allows for fractionation of the parent molecular-weight distribution. In addition to observing the established shift in phase boundaries, we find the emergence of significant two-phase coexistence regions causing, for instance, the dis...

Equilibrium behavior of symmetric ABA triblock copolymer melts

Evolution in off-critical diblock copolymer melts

We study the evolution of diblock copolymer melts in which one component has small volume fraction. In this case one observes phase morphologies which consist of small spheres of the minority component embedded in the other component. Based on the Ohta-Kawasaki free energy one can set up an evolution equation which has the interpretation of a gradient flow. We restrict this gradient flow to mor...

Comparison of A-block polydispersity effects on BAB triblock and AB diblock copolymer melts.

Recent experiments on triblock copolymer melts suggest that polydispersity effects are dramatically enhanced when polydisperse blocks are constrained by both ends to the internal interfaces of an ordered morphology. To quantify the relevance of architecture, we compare BAB triblock and AB diblock copolymer melts with polydisperse A blocks and monodisperse B blocks, using self-consistent field t...

Multicritical Phenomena and Microphase Ordering in Random Block Copolymer Melts

A mean-field analysis of microphase separation and phase behavior is described for melts of linear A-B multiblock copolymers, each chain consisting of a stochastic sequence of flexible segments (each with M monomers), AM and BM, for a total of Q >> 1 segments per chain. We find a phase diagram similar to that for statistical A-B copolymers (M = 1) but with an isotropic Lifshitz point that shoul...