Multiscale Effects of Interfacial Polymer Confinement in Silica Nanocomposites

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• 作者：H. Samet Varol ; M. Alejandra S谩nchez ; Hao Lu ; Joe E. Baio ; Christian Malm ; Noemi Encinas ; Marius R. B. Mermet-Guyennet ; Nicolas Martzel ; Daniel Bonn ; Mischa Bonn ; Tobias Weidner ; Ellen H. G. Backus ; Sapun H. Parekh
• 刊名：Macromolecules
• 出版年：2015
• 出版时间：November 10, 2015
• 年：2015
• 卷：48
• 期：21
• 页码：7929-7937
• 全文大小：544K
• ISSN：1520-5835

文摘

Dispersing hydrophilic nanofillers in highly hydrophobic polymer matrices is widely used to tune the mechanical properties of composite material systems. The ability to control the dispersion of fillers is closely related to the mechanical tunability of such composites. In this work, we investigate the physical鈥揷hemical underpinnings of how simple end-group modification to one end of a styrene鈥揵utadiene chain modifies the dispersion of silica fillers in a polymer matrix. Using surface-sensitive spectroscopies, we directly show that polymer molecular orientation at the silica surface is strongly constrained for silanol functionalized polymers compared to nonfunctionalized polymers because of covalent interaction of silanol with silica. Silanol functionalization leads to reduced filler aggregation in composites. The results from this study demonstrate how minimal chemical modifications of polymer end groups are effective in modifying microstructural properties of composites by inducing molecular ordering of polymers at the surface of fillers.