New dynamics in poly(propylene glycol) based glass-forming nanocomposites

Results of broadband dielectric spectroscopy and rheological studies of poly(propylene glycol) + SiO2 nanocomposites are presented. They show that the dynamics in high-concentrated composites is dominated by confinement and adsorption effects. The most notable finding is the impact of nanoparticles on fragility, the fractional translational - orientational decoupling and the shift of dynamics towards the pure Vogel-Fulcher-Tammann pattern, associated with the lack of local symmetry preferences.