Dynamic Simulations of the "Bricks-and-Mortar" Mesophase in Miktoarm Block Copolymer/Homopolymer Blends

A new mesophase in binary blends of A-b-(B-b-A')_n miktoarm star block copolymers and A homopolymers has recently been discovered experimentally and explored with field theoretic simulations. This mesophase consists of aperiodic discrete domains of A embedded in a continuous matrix of B up to extremely high concentrations of homopolymers. We investigate the structural and dynamic properties of the phase, including its linear rheological behavior, response to shear, and response to uniaxial tension using three-dimensional particle-based simulations. We highlight the role of molecular bridging on dominating the mechanical properties of the phase, as well as the unique response of the mesophase to shear, including the evident destruction of the bricks-and-mortar phase upon the application of shear.