| 초록 |
Electrical properties of carbon nanomaterials (CNM) reinforced polymer composites depend on various factors such as inherent properties of CNM, the degree of dispersion, aspect ratio, shape and content, etc. Especially, the degree of dispersion is well known as one of the most important factors in electrical properties. Nondestructive damage sensitivity and electrical properties of surface functionalized carbon nanotube (CNT) and nanofiber (CNF)/epoxy composites were investigated using electro-micromechanical technique and acoustic emission (AE). Carbon black (CB) was used for the comparison. To improve the degree of dispersion, the surface of CNT and CNF was functionalized by dilute sulfuric-nitric acid. For acid-treated case, the sensitivity for fiber damage such as fiber fracture and fiber tension increased at all CNMs by improved the degree of dispersion. For both the untreated and treated cases, damage sensitivity was highest for CNT/epoxy composites, and for CB case they were lowest. The electrical properties of carbon nanocomposites were correlated with the result of morphological observation. The control of dispersion degree should be very important factor in electrical properties. Damage sensitivity and electrical properties of CNT and CNF/epoxy composites could be improved using surface functionalization. Acknowledgement: This work was financially supported from CNMT of the 21st C Frontier R&D program by MOST, through ERI, GNU. |
