| 초록 |
A composite of carbon nanotubes (CNTs) and polymers has excellent optical and electrical properties due to the high aspect ratio of the CNTs. The electric conductivity of the composite could be, however, deteriorated significantly by many factors. Especially, shear, usually applied in the injection molding process or the extrusion process, could reduce the electric conductivity significantly. However, the question as to how shear leads to a catastrophic decrease in the electric conductivity remains unanswered. Here, we report a molecular simulation study of CNT-polymer composites in a simple shear flow. We find that the CNT-polymer composites form an isolated aggregate of CNTs above a critical shear rate. The aggregate formation leads to a breakdown of the percolating electric network, decreasing the electric conductivity. In order to study the effect of the CNT concentration and shear rate, we construct pseudo-phase diagrams for both aggregation and percolating network formation. |
