Abstract

The importance of proper CNT dispersion is still the main challenge in CNTs doped epoxy nanocomposites. Therefore, this study was aimed to investigate the effect of toroidal stirring-assisted sonication on final mechanical, electrical and electromechanical properties of the nanocomposites. Two different samples were produced i.e. one with just sonication (M1 batch) and the other was produced using a combination of sonication and high toroidal stirring in an iterative approach (M2 batch). While piezoresistivity performance of the CNT based nanocomposites were mainly investigated in the literature for tensile mode and less attempts were conducted in presence of a pre-crack, both tensile and fracture tests were performed in this study to measure mechanical and electromechanical properties of the nanocomposites. SEM and FESEM were used for the microstructural characterizations. Results showed that M2 batch resulted in a better mechanical, electrical, and piezoresistivity performance than the M1 batch resulting from a better CNT dispersion and less amount of voids in the former compared to the latter. In fact, tensile strength and fracture toughness was increased by 70% and 17%, respectively for M2 batch with respect to M1 batch . Moreover, piezoresistive-sensitivity of the M2 batch increased 14%, compared to M1 batch. Finally, different trends in piezoresistivity was revealed in the fracture test before the occurrence of macroscopic damage, attributed to state of CNT dispersion and manifesting as a negative and positive trend for the M2 and M1 batches, respectively.

摘要

适当的 CNT 分散的重要性仍然是 CNT 掺杂环氧纳米复合材料的主要挑战。因此，本研究旨在研究环形搅拌辅助超声处理对纳米复合材料最终机械、电气和机电性能的影响。生产了两种不同的样品，即一种仅采用超声处理（M1 批次），另一种采用迭代方法结合超声处理和高速环形搅拌（M2 批次）生产。虽然基于 CNT 的纳米复合材料的压阻性能主要在拉伸模式的文献中进行研究，并且在存在预裂纹的情况下进行的尝试较少，但在本研究中进行拉伸和断裂测试以测量纳米复合材料的机械和机电性能。SEM 和 FESEM 用于微观结构表征。结果表明，与 M1 批次相比，M2 批次具有更好的机械、电气和压阻性能，这是由于与后者相比，前者的 CNT 分散性更好且空隙量更少。事实上，相对于 M1 批次，M2 批次的拉伸强度和断裂韧性分别提高了 70% 和 17%。此外，与 M1 批次相比，M2 批次的压阻灵敏度提高了 14%。最后，在发生宏观损伤之前的断裂试验中揭示了压阻率的不同趋势，这归因于 CNT 分散状态，并且分别表现为 M2 和 M1 批次的负趋势和正趋势。电气和压阻性能优于 M1 批次，这是由于与后者相比，前者具有更好的 CNT 分散性和更少的空隙量。事实上，相对于 M1 批次，M2 批次的拉伸强度和断裂韧性分别提高了 70% 和 17%。此外，与 M1 批次相比，M2 批次的压阻灵敏度提高了 14%。最后，在发生宏观损伤之前的断裂试验中揭示了压阻率的不同趋势，这归因于 CNT 分散状态，并且分别表现为 M2 和 M1 批次的负趋势和正趋势。电气和压阻性能优于 M1 批次，这是由于与后者相比，前者具有更好的 CNT 分散性和更少的空隙量。事实上，相对于 M1 批次，M2 批次的拉伸强度和断裂韧性分别提高了 70% 和 17%。此外，与 M1 批次相比，M2 批次的压阻灵敏度提高了 14%。最后，在发生宏观损伤之前的断裂试验中揭示了压阻率的不同趋势，这归因于 CNT 分散状态，并且分别表现为 M2 和 M1 批次的负趋势和正趋势。相对于M1批次，M2批次的拉伸强度和断裂韧性分别提高了70%和17%。此外，与 M1 批次相比，M2 批次的压阻灵敏度提高了 14%。最后，在发生宏观损伤之前的断裂试验中揭示了压阻率的不同趋势，这归因于 CNT 分散状态，并且分别表现为 M2 和 M1 批次的负趋势和正趋势。相对于M1批次，M2批次的拉伸强度和断裂韧性分别提高了70%和17%。此外，与 M1 批次相比，M2 批次的压阻灵敏度提高了 14%。最后，在发生宏观损伤之前的断裂试验中揭示了压阻率的不同趋势，这归因于 CNT 分散状态，并且分别表现为 M2 和 M1 批次的负趋势和正趋势。