The Study of Carbon Nanotubes Purification and the Properties of Their Composites

• Main Authors: Der-Chin Peng, 彭德欽
• Other Authors: Wern-Shiarng Jou
• Format: Others
• Language: en_US
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/53077781382594621598

碩士 === 國立高雄應用科技大學 === 模具工程系 === 97 === Owing to the purity of products synthesized by arc discharged method (ADM) is low, the products containing multi-wall carbon nanotubes (MWNTs), carbon nanocapsules (CNCs) and amorphous carbon. In order to increase the purity of carbon nanotubes (CNTs), liquid phase oxidation (LPO) and vapor phase oxidation (VPO) are performed to purify the CNTs, respectively. Thus, compares with effects of the purity and microstructure of CNTs by either LPO or VPO. Further investigates the purification effect upon the electromagnetic shielding effectiveness (EM SE) of the CNTs/LCP composites (CLCs). In this study, liquid crystal polymers (LCPs) are used to the matrix for fabrication of CLCs, and mixed uniformly with the purified/unpurified CNTs, the standard specimens were fabricated by mold compressing technique. Thus, CNTs and CLCs were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and Raman spectra. Compares with the effects of the CNTs microstructure by either LPO or VPO, and further tests the EM SE of purified CLCs according to ASTM 4935. This study compares with the microstructure of CNTs with or without purification. The purification effect of VPO on CNTs is better than that of LPO. The results of SEM indicate that the VPO conserve the originally high aspect ratio of CNTs, the conductive network through CNTs in LCP matrix can be observed in the cross-sectional images on the CLCs. From TEM analysis, the re-forming CNTs under the high temperature environment are observed. Both the XRD and Raman spectra confirm the graphitic degree of purified CNTs is higher than that of unpurified CNTs. The CNTs have the best purity at 973 K (ID/IG ratio = 0.4593), the enhancement of purity is 48%. The EM SE of purified CLCs approaches 32 dB is better than that of unpurified CLCs (about 26 dB), the enhancement of EM SE is 23%. The results in this study demonstrate that the VPO can increase the purity of CNTs efficiently and further improves the EM SE of CLCs. The CLCs can be applied on the anti-EM SE products such as electronic packaging materials in the future.