Thermal−Electrical Character of in Situ Synthesized Polyimide-Grafted Carbon Nanofiber Composites
Thermal−Electrical Character of in Situ Synthesized Polyimide-Grafted Carbon Nanofiber Composites
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DOI：
10.1021/ma801525f
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发表时间：
2008-10
期刊：
影响因子：
5.5
通讯作者：
M. Arlen;David H. Wang;J. Jacobs;R. Justice;A. Trionfi;Julia W. P. Hsu;Dale Schaffer;Loon-Seng Tan-L
中科院分区：
文献类型：
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作者：
M. Arlen;David H. Wang;J. Jacobs;R. Justice;A. Trionfi;Julia W. P. Hsu;Dale Schaffer;Loon-Seng Tan-L
尽管聚合物-碳纳米管（CNT）纳米复合材料取得了成功，但对于外部扰动（包括温度和应力）对电响应的影响、其再现性以及随后与CNT-CNT接触结的分解形态和分子细节的拓扑结构的关系的深入理解并不完整。使用原位合成方法，制备了两个系列的聚酰亚胺（CP 2）-碳纳米管（CNF）复合材料，其具有定量（小角X射线散射）可比的CNF分散体，但CNF-聚合物界面的结构不同。氨基官能化的CNF（FCNF）使得能够在CNF上直接形成CP 2接枝物，而原始CNF（PCNF）导致碳纳米管和CP 2基质之间的相对弱的界面。一般来说，低频交流阻抗测量很好地描述了渗流键模型，产生的渗流阈值低于1体积%（0.24和0.68体积%的PCNF− CP 2和FCNF− CP 2.
Notwithstanding the success of polymer−carbon nanotube (CNT) nanocomposites, a solid understanding of the impact of external perturbations, including temperature and stress, on the electrical response, its reproducibility, and the subsequent relationship to the topology of the percolative morphology and molecular details of the CNT−CNT contact junction is not complete. Using an in situ synthesis approach, two series of polymide (CP2)−carbon nanofiber (CNF) composites are prepared with quantitatively (small-angle X-ray scattering) comparable CNF dispersions, but differing in the structure of the CNF−polymer interface. Amino-functionalized CNFs (FCNFs) enable direct formation of CP2 grafts onto the CNFs, whereas pristine CNFs (PCNFs) result in a relatively weak interface between the carbon nanofiber and CP2 matrix. In general, low-frequency ac impedance measurements are well described by the percolation bond model, yielding a percolation threshold below 1 vol % (0.24 and 0.68 vol % for PCNF−CP2 and FCNF−CP2...