| 초록 |
In recent years, electromagnetic interference (EMI) has become a critical problem to electric devices because it causes the malfunction of electric devices, such as the control panels of airplanes, mobile phones and many computers, and has adverse effects on human diseases, such as breast cancer and leukemia. Among the electric devices, the malfunction of an electric control unit (ECU) in automobiles by EMI is considered as a key reason for sudden acceleration. To ensure the safety of driving automobiles, major car makers have been trying to develop high performance and light EMI shielding ECU housing materials [1-3]. In this work, the EMI shielding effectiveness (SE) of carbon nanotubes/carbon fibers-reinforced polyolefin matrix composites are investigated with various preparation conditions such as the content of carbon fibers and carbon nanotubes, the presence of metal additives, and mixing speed and time. It was found that the EMI-SE of the composites increased with filler contents and metal additives. The EMI-SE was also depended on the average length of carbon fibers. These results indicate that the content and length of carbonaceous fillers determine the electric networks in the composites, resulting in the control of the EMI-SE of the composites. |
