| 초록 |
Carbon nanotube (CNT) and nanofiber (CNF) reinforced polymeric matrix composites have excellent electrical conductivity at relatively low percolation threshold. Nondestructive damage sensitivity of functionalized carbon nanotube and nanofiber/epoxy composites were investigated using electro-micromechanical technique and acoustic emission (AE). Carbon black (CB) was used for the comparison. To improve the electrical conductivity and the degree of dispersion, the surface of CNT and CNF was treated by sulfuric-chromic acid. For both the untreated and acid-treated cases the sensitivity for fiber damage such as fiber fracture and fiber tension was highest for CNT/epoxy composites, and for CB case they were lowest. For acid-treated case sensitivity of CNT and CNF/epoxy composites was almost same at high content, whereas the sensitivity of CNT/epoxy composite was higher at low content due to their large aspect ratio and high electrical conductivity. In this work, damage sensitivity of CNT and CNF/epoxy composites could be improved using surface functionalization. The control of dispersion degree is very important factor and temperature change can affect on the electrical properties significantly. These parameters effect will be investigated consequently. Acknowledgement: This work was financially supported from CNMT of the 21st C Frontier R&D program by MST, through ERI, GNU. |
