This work discusses dynamics and polarizability of polymer chains in the interfacial layer around nanoparticles based on characteristics of the chains: stiffness (C-infinity) and cohesive energy density (CED). Three polymers differing pairwise in C-infinity and CED were selected, and effects of low concentration of nano-titania on glass transition temperature (Tg), thickness of interfacial layers, and dielectric behavior of polymers were investigated. As a result of interfacial loose layers formed around nano-titania, polymethylmethacrylate with high C-infinity and CED gained more segmental mobility, resulting in lower Tg, and higher dielectric permittivity than the neat polymer. Similar changes with less magnitude were observed for polystyrene having similar Coo but less CED. However, due to immobilized dense layers around nano-titania, ethylene propylene rubber with low C-infinity and CED lost its segmental mobility, but both Tg and permittivity of nano-composite increased. Broadband dielectric analysis showed that an optimum segmental mobility in the interfacial layer is needed for enhanced chain polarization and dielectric permittivity. (C) 2018 Elsevier Ltd. All rights reserved.