Dynamics at the Polymer/Nanoparticle Interface in Poly(2-vinylpyridine)/Silica Nanocomposites

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• 作者：Adam P. Holt ; Philip J. Griffin ; Vera Bocharova ; Alexander L. Agapov ; Adam E. Imel ; Mark D. Dadmun ; Joshua R. Sangoro ; Alexei P. Sokolov
• 刊名：Macromolecules
• 出版年：2014
• 出版时间：March 11, 2014
• 年：2014
• 卷：47
• 期：5
• 页码：1837-1843
• 全文大小：381K
• 年卷期：v.47,no.5(March 11, 2014)
• ISSN：1520-5835

文摘

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鈥? 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 鈥渄ead layer鈥? However, its existence might provide some explanation for controversies surrounding the dynamics of polymer nanocomposites.