Phase separation morphology of a mixed polymer monolayer

Phase separation of a mixed monolayer of poly(octadecyl methacrylate) (PODMA) and poly(isobutyl methacrylate) (PiBMA) was investigated by Brewster angle microscopy (BAM) and atomic force microscopy (AFM). At 20 degrees C, solid-like PODMA forms network-like structures including liquid-like PiBMA domains due to the strong cohesive force between the long alkyl side chains of PODMA. After annealing at 40 degrees C for 60 min, the morphology of the mixed monolayer was drastically changed by the fusion of PODMA, resulting in a completely phase separated structure.