標題: | Quantitative appraisal of the interfacial anchoring state of polyaromatic hydrocarbons during the formation of C/C composites |
作者: | Lin, Cheng-Te Tsai, Min-Chiao Lee, Chi-Young Chiu, Hsin-Tien Chin, Tsung-Shune 應用化學系 Department of Applied Chemistry |
公開日期: | 1-四月-2010 |
摘要: | The preferred anchoring state for polycyclic aromatic hydrocarbons (PAHs) pyrolyzed onto carbon substrates has been studied by semi-quantitative methods, examining their interfacial lattice arrangements. The samples were prepared by decomposing petroleum pitch inside carbon nanotubes resulting in a variety of crystallinities forming one-dimensional C/C composites. Studies indicate that the preferred anchoring state of PAH molecules depends on the nature of the substrate. Accordingly the PAHs in mesophase pitch should exhibit a face-on orientation on the carbonaceous substrates, including a graphite sheet, glassy carbon, and pyrolytic carbon. However, it showed that the anchoring state (face-on or edge-on) of PAH units can be altered even on carbonaceous substrates. The results demonstrated that in C/C composites the anchoring state is predominantly determined by the relative degree of crystallinity of the pitch/carbon substrate, and can be semi-quantitatively estimated using the I(D)/I(G) ratio from Raman spectra. Face-on anchoring is preferred when the I(D)/I(G); ratio of substrate is smaller (higher crystallinity) than that of the pyrolyzed precursor, whereas edge-on anchoring is favored when it is larger. Such an estimation method is useful in tailoring microstructures in the fabrication of C/C composites using PAH precursors. (C) 2009 Elsevier Ltd. All rights reserved. |
URI: | http://dx.doi.org/10.1016/j.carbon.2009.11.024 http://hdl.handle.net/11536/5557 |
ISSN: | 0008-6223 |
DOI: | 10.1016/j.carbon.2009.11.024 |
期刊: | CARBON |
Volume: | 48 |
Issue: | 4 |
起始頁: | 1049 |
結束頁: | 1055 |
顯示於類別: | 期刊論文 |