Agglomeration-free silica NPs in dry storage for PBT nanocomposite

Dispersion of nanoparticles actually plays a key role in preparing high-performance nanocomposites. Within sol–gel procedures, the Stöber method is widely used to produce monodisperse systems of silica particles with controlled size and morphology. However, if stored as dried, the Stöber silica nanoparticles form stable agglomerates that no longer resuspend. Herein, we propose a novel straightforward methodology that overcomes the irreversible aggregation of particles, ultimately leading to a very good dispersion of the filler within the polymeric matrix without any coupling agent, even long time after their preparation. This synthesis approach has been exploited to produce PBT/SiO2 nanocomposites, as a model system. The produced nanocomposites have been analyzed and characterized by multiple techniques proving a fine dispersion of the filler within the matrix, as well as a significant increase in both thermal and dynamic mechanical properties. The proposed strategy ensures high compatibility with current industrial compounding facilities and far-reaching implementation in the preparation of polymer nanocomposites.