Study On Modifications Of Carbon Nanotubes And Applications In Composites

Carbon nanotubes (CNTs), a novel one-dimensional carbon nano-material, are considered as ideal reinforcing materials for composites due to their unique structure, excellent electrical conductivity and mechanical properties. The unique property of CNTs can be utilized effectively when combining the characteristics of CNTs and polymers. Unfortunately, due to high surface free energy, CNTs will be aggregated easily. This will limit the applications of CNTs in composites. In order to improve the dispersion of CNTs in various media, the modification of CNTs surface were carried out in this paper. Additionally, the applications of the modified CNTs in nanocomposites were investigated. Moreover, the CNT/ epoxy aclrylate resin UV cured coatings were prepared by mixing method for the first time. The works in this paper have important significance and practical value for development of functional composites.The main results obtained in this paper are shown as follows:1. The purification, modification and functionalization of CNTs were carried out byHNO₃ treatment. After refluxing by HNO3, it can be seen from Reman spectrum and SEM images that the purification of CNTs can be improved obviously. The surface functional groups carboxyl (-COOH), hydroxyl (-OH) and carbonyl (>C=O) groups will be introduced on the surface of CNTs according to the infrared spectrum. In this way, in-situ modification of CNTs by caprolactam can be achieved successfully.2. The hetropolyacids (H₇PMo₁₂O₄₂.xH₂O) was employed to promote the dispersion of CNTs in water. The results indicates that when the mass ratio of CNTs to H₇PMo₁₂O₄₂.xH₂O is 1: 10 (w/w) , the best dispersion of CNTs in water was reached. The effect of CNT pretreatment and sonicating time for CNT-H₇PMo₁₂O₄₂.xH₂O on the dispersion of CNTs in water were also studied3. CNT-POM-PAni/graphite (G) electrodes were prepared by mixing CNT-POM and Pani in solutions and the corresponding electrochemical capacitive properties have been investigated. The following results can be obtained: The series resistance of the electrode can be decreased effectively and the power characterics of the electrode can be improved obviously by addition of 1%CNTs. Comparied with PAni/G, POM-PAni/G and CNT-PAni/G, CNT-POM-PAni/Gelectrode has high...