Controlling the Location of Nanoparticles in Polymer Blends by Tuning the Length and End Group of Polymer Brushes

This paper investigates controlling the location of nanoparticles (NPs) in a phase-separated polymer blend of deuterated poly(methyl methyl methacrylate) (dPMMA) and poly(styrene-ran-acrylonitrile) (SAN). Silica NPs are grafted with PMMA brushes having molecular weights of 1800, 21000, and 160000 at fixed grafting density. Using ion beam milling combined with SEM imaging, NP location and morphology are investigated for blends containing 10 wt % NP. With increasing brush length, the NPs are found to segregate to the dPMMA/SAN interface, partition between the interface and dPMMA phase, or locate in the dPMMA phase, respectively.