Polymer/Star-Polymer composites: structure and dynamics of bulk and confined materials*

Polymer-grafted nanoparticles (NP) are versatile building blocks to create tunable particle superstructures and polymer nanocomposites with customizable properties. Polymer grafted NP are topologically very similar to star polymers. While nanocomposites with polymer-grafted NP have been explored recently, comparatively little is known about composites consisting of star polymers and chain polymers, or star polymers in polymer thin films. We investigate how both the number of arms and molecular weight affect the morphology of self-assembled structures in both a bulk polymer material and an ultra-thin polymer film. Additionally, we study how star polymers affect the glass transition of these composites and films. In doing so, we also examine how star polymers affect the nature of cooperative molecular motions in the matrix and film, and how this potentially relates to changes in the mechanical and rheological properties of the material.