Dynamics at the Polymer/Nanoparticle Interface in Poly(2-vinylpyridine)/Silica Nanocomposites.
The static and dynamic properties of poly(2-vinylpyridine)/silica nanocomposites are investigated by temperature modulated differential scanning calorimetry, broadband dielectric spectroscopy (BDS), small-angle X-ray scattering (SAXS), and transmission electron microscopy. Both BDS and SAXS detect the existence of an interfacial polymer layer on the surface of nanoparticles. The results show that whereas the calorimetric glass transition temperature varies only weakly with nanoparticle loading, the segmental mobility of the polymer interfacial layer is slower than the bulk polymer by 2 orders of magnitude. Detailed analysis of BDS and SAXS data reveal that the interfacial layer has a thickness of 4 6 nm irrespective of the nanoparticle concentration. These results demonstrate that in contrast to some recent articles on polymer nanocomposites, the interfacial polymer layer is by no means a dead layer . However, its existence might provide some explanation for controversies surrounding the dynamics of polymer nanocomposites.
- University of Tennessee (UTK) and Oak Ridge National Laboratory (ORNL)
- Publication Date:
- OSTI Identifier:
- DOE Contract Number:
- Resource Type:
- Journal Article
- Resource Relation:
- Journal Name: Macromolecules; Journal Volume: 47; Journal Issue: 5
- Research Org:
- Oak Ridge National Laboratory (ORNL)
- Sponsoring Org:
- SC USDOE - Office of Science (SC)
- Country of Publication:
- United States