Confinement-Induced Deviation of Chain Mobility and Glass Transition Temperature for Polystyrene/Au Nanoparticles

The mobility and glass transition temperature ( T g ) for polymers under nanoscale confinement differ substantially from the bulk. Whereas many studies have focused on the one-dimensional confinement, it has great significance to extend studies to higher geometries. Here, we systematically investigate the mobility by dipolar-filter sequence in solid-state NMR and T g by DSC for thiolated polystyrene (PS-SH) on gold nanoparticles. The increase in T g and signal suppression in NMR spectra clearly indicate that the surface confinement dominates molecular mobility as well as T g . The molecular weight of PS-SH and nanoparticles size show significant influence on the immobilization and T g . Our results can be fitted with a core–two shell model; the inner shell is under strong constraints while the outer shell with less confinement. This work is essential to better understand the confinement effect and also provides a step toward the ultimate desire to tailor the properties of nanomaterials.