Structure and dynamics of architecturally engineered all-polymer nanocomposites

We present nanocomposites formed by using glassy star-shaped polymers as nanofillers and dispersing them in soft matrices. The resulting ‘architecturally engineered’ nanocomposites structurally reside between the linear homopolymer blends and the conventional polymer nanocomposites with solid fillers. We observed that the star polymers can induce reinforcement that can be as strong as that of solid nanoparticles, or softening depending on the compactness and concentration of the nanoparticles. We showed that the remarkable influence of filler architecture on the rheological properties can be traced back to the dynamical features at the segmental and the chain level which we investigated using neutron scattering over a wide range of time and lenghts scales in the glassy and melt states of the nanocomposites. The local and segmental dynamics as well as chain-chain entanglements are all modified by polymer architecture, offering a novel approach for tuning the physical properties of all-polymer based composites.