Dynamics in poly(propylene glycol) and silica oxide nanoparticles composite glassforming system

TL;DR

This study investigates how silica oxide nanoparticles affect the molecular dynamics and relaxation behavior of poly(propylene glycol) in nanocomposites, revealing confinement, adsorption effects, and changes in fragility.

Contribution

It provides new insights into the influence of nanoparticles on the relaxation dynamics and fragility of polymer nanocomposites using dielectric and rheological methods.

Findings

Dynamics follow Vogel-Fulcher-Tammann pattern

Nanoparticles significantly influence relaxation times and fragility

Confinement and adsorption effects are key in high-concentration composites

Abstract

Results of broadband dielectric spectroscopy and rheological studies of poly(propylene glycol) + SiO${_2}$ nanocomposites are presented. They show that the dynamics in high-concentrated composite is determined by confinement and adsorption effects, resulting from interactions of confined polymers correspond with the host system at the interface between PPG and solid nanoparticles. The evolution of relaxation times follows the clear Vogel-Fulcher-Tammann pattern, what is proved by the supplementary activation energy temperature index analysis. The strong influence of nanoparticles on the transitional dynamics and the fragility in the ultraviscous domain was noted.