Interfacial Stress Transfer in Graphene Oxide Nanocomposites
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- 作者：Zheling Li ; Robert J. Young ; Ian A. Kinloch
- 刊名：ACS Applied Materials & Interfaces
- 出版年：2013
- 出版时间：January 23, 2013
- 年：2013
- 卷：5
- 期：2
- 页码：456-463
- 全文大小：421K
- 年卷期：v.5,no.2(January 23, 2013)
- ISSN：1944-8252
文摘
Raman spectroscopy has been used for the first time to monitor interfacial stress transfer in poly(vinyl alcohol) nanocomposites reinforced with graphene oxide (GO). The graphene oxide nanocomposites were prepared by a simple mixing method and casting from aqueous solution. They were characterized using scanning electron microscopy, X-ray diffraction, and polarized Raman spectroscopy and their mechanical properties determined by tensile testing and dynamic mechanical thermal analysis. It was found that GO was fully exfoliated during the nanocomposite preparation process and that the GO nanoplatelets tended align in the plane of the films. The stiffness and yield stress of the nanocomposites were found to increase with GO loading but the extension to failure decreased. It was shown that the Raman D band at 1335 cm鈥? downshifted as the nanocomposites were strained as a result of the interfacial stress transfer between the polymer matrix and GO reinforcement. From knowledge of the Gr眉neisen parameter for graphene, it was possible to estimate the effective Young鈥檚 modulus of the GO from the Raman D band shift rate per unit strain to be of the order of 120 GPa. A similar value of effective modulus was found from the tensile mechanical data using the 鈥渞ule of mixtures鈥?that decreased with GO loading. The accepted value of Young鈥檚 modulus for GO is in excess of 200 GPa and it is suggested that the lower effective Young鈥檚 modulus values determined may be due to a combination of finite flake dimensions, waviness and wrinkles, aggregation, and misalignment of the GO flakes.