Modulating the Domain Morphology of A-B Diblock Copolymer Brushes in Selective Solvents by grafting Homopolymers C

摘要

Immiscible multi-component polymer brushes, including block copolymer brushes and mixed homopolymer brushes, exhibit lateral and/or perpendicular microphase separation. The morphology depends on the molecular architecture of the constituents (e.g. monomer chemistry, chain topology, molecular weight, grafting density) and the external environment (e.g. solvent selectivity and quality). Immiscible A-B diblock copolymer brushes in contact with a selective solvent, in which the grafted component, A, is soluble but which is a poor solvent for the top block B, form morphologies, where the B-component aggregates into domains embedded in a matrix of swollen A blocks. Depending on the grafting density and the relative fraction of the B- block, a variety of domain shapes (e.g. layer, ripple- or dimple-like structures) is observed. Here, we explore to what extent the shape and location of the collapsed B-domains can be controlled by grafting an additional homopolymer C, which is immiscible with the B- component but swollen by the solvent.