Multi-scale modeling of surfactant-stabilized carbon nanotube networks

为了研究和优化三维碳纳米管（CNT）网络的宏观力学性能，将开发一种结合分子和有限元模拟的多尺度方法。碳纳米管网络材料在功能应用方面非常重要，例如作为超级电容器、燃料电池和传感器的电极，以及从骨修复支架到自下而上的增强聚合物基复合材料设计，再到汽车减震材料等结构应用。所有这些应用，即使它们主要是功能性的，也需要碳纳米管材料具有一定的机械性能。一个纯粹的碳纳米管网络是机械弱的，因为在管之间的负载传递不足，但它可以通过分子夹加强。这些夹钳是在水溶液中形成的，但可以用化学方法稳定，以便使复合材料适用于干燥状态。这种方法的重点是加强管/管的接触，形成稳定的接头，同时保持重要的开孔结构。这个项目要回答的关键问题是，单个关节的性能如何影响材料的宏观性能，这可以通过分子模拟来研究。由于分子模拟无法达到宏观水平，因此将发展多尺度方法来实现这一目标。材料的宏观特性将基于单个关节的特性来预测，而这些特性最终与形成关节的单个分子的特性联系在一起。第二个目标更加雄心勃勃和具有挑战性，那就是建立反向链接，并试图回答这样一个问题，即哪些分子能够提供所需的联合性质，以获得目标宏观性质。

To investigate and optimize the macroscopic mechanical properties of 3D carbon nanotube (CNT) networks a multi-scale approach will be developed combining molecular and finite elements simulations. Carbon nanotube network materials are of great importance for functional applications, e.g. as electrodes for super-capacitors, fuel cells and sensors, as well as for structural applications ranging from scaffolds for bone repair, to the bottom-up design of reinforced polymer matrix composites, to shock adsorbing materials for cars. All these applications, even if they are primarily functional, require certain mechanical properties of the CNT material. A pure CNT network is mechanically weak due to insufficient load transfer between the tubes, but it can be strengthened by molecular clamps. Those clamps are formed in aqueous solution but can be stabilised chemically in order to make the composite material applicable in the dry state. This approach focuses on strengthening the tube/tube contacts to form stable joints, while preserving the vital open-pore structure. The key question to be answered by this project is how the properties of an individual joint, which can be studied by molecular simulations, affect the macroscopic properties of the material. As the macroscopic level is inaccessible for molecular simulation a multiscale approach will be developed to achieve this. The macroscopic properties of the material will be predicted based on the properties of individual joints which are ultimately linked to the properties of the individual molecules forming the joint. The even more ambitious and challenging second aim is to establish the reverse link and attempt to answer the question which molecules would provide the required joint properties to obtain the target macroscopic properties.