Aggregation of nanoparticles and their effect on mechanical properties of carbon nanotube networks
Aggregation of nanoparticles and their effect on mechanical properties of carbon nanotube networks
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DOI：
10.1016/j.commatsci.2021.110970
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发表时间：
2022-02
影响因子：
3.3
通讯作者：
Yue Wu;Chao Wang;Tian Yang
中科院分区：
文献类型：
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作者：
Yue Wu;Chao Wang;Tian Yang
纳米颗粒在许多实际应用中被广泛用于调节碳纳米管(CNT)网络的力学和物理性能。然而，纳米粒子在碳纳米管网络中的分布及其对微结构演化和力学性能的影响仍然不清楚。我们利用粗粒度分子动力学(CGMD)模拟对这些问题进行了系统的研究。首先，我们发现相对于环境温度和循环载荷的频率，NPs的相对结合能和循环载荷的应变幅度是控制NPs聚集的更重要的因素；还发现相对结合能较大且在较大应变循环载荷下的NPs在CNT网络中聚集得更严重。其次，我们观察到，在纳米粒子的临界体积分数(∼21.6%)下，材料的杨氏模量和拉伸强度分别提高了3.2倍和2.0倍(∼21.6%)。最后，揭示了纳米颗粒增强管间连接和抑制碳纳米管束形成的潜在机制。这些结果将有助于碳纳米管基先进材料的优化设计。
Nanoparticles (NPs) are widely used to tune the mechanical and physical properties of carbon nanotube (CNT) networks in many practical applications. However, the distribution of NPs in CNT networks and their effects on microstructural evolutions and mechanical properties remain elusive. We employed the coarse-grained molecular dynamics (CGMD) simulations to systematically investigate these issues. First, we found that compared to ambient temperature and the frequency of cyclic loads, the relative cohesion energy of NPs and strain amplitude of cyclic loads are more important factors for controlling the aggregation of NPs; it was also revealed that NPs with larger relative cohesion energy and in larger-strain cyclic loads would aggregate more severely in CNT networks. Second, we observed that the Young's modulus and the tensile strength of the material can be increased by up to ∼3.2 and ∼2.0 times, respectively, at the critical volume fraction of NPs (∼21.6%). Finally, the underlying mechanisms by which NPs strengthen the inter-tube joints and constrain the bundling of CNTs are unveiled. These results should be useful for the optimal design of CNT-based advanced materials.