Size effect of Al₂O₃ nanowires on the molecular relaxation in epoxy composites

The size effect of Al₂O₃ nanowires on the molecular relaxation of an epoxy system was investigated by means of DSC and dielectric relaxation spectroscopy. T_g and activation energy of dielectric relaxation decreased with the incorporation of the nanowires. To explain the observed results, a coarse-grained confined-region structure model is proposed, and on the basis of this model, the change in molecular motion arising from the nanowires could be understood. The variations of thermal stability and water absorption for the nanocomposites were also discussed. These original experimental results should be helpful in scientific research and nanocomposite applications.