Self-assembly of Janus rods in binary blends of polymers. Part II: phase behavior under shear flow and relaxation*

Janus particles are highly active at the interface of immiscible fluids and thus they can self-assemble into different structures when incorporated into multiphase systems. In Part I, we performed mesoscale Dissipative Particle Dynamics simulations to investigate the influence of individual parameters on the structures formed by Janus rods at the interface of two immiscible liquids. In particular, we showed how interfacial orientation and self-assembly of Janus rods are highly influential in controlling the phase separation process when added to a polymer blend. Moreover, we also monitor herein the microstructures formed by these systems under flow conditions and upon relaxation after flow cessation. We verified in our simulations various stabilizing effects provided by Janus rods of higher aspect ratio that present a tilted configuration at the interface. We also studied the Janus aggregate-breakup process during shear and how these interfacial aggregates rebuild upon flow cessation. The results of this study can be used for designing new approaches for directing nano-particles into desired morphologies by applying shear flow.