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，将分子模拟和有限元模拟相结合，发展了一种多尺度方法。碳纳米管网络材料在超级电容器、燃料电池和传感器的电极等功能应用以及从骨修复支架到增强聚合物基复合材料的自下而上设计到汽车减震材料等结构应用领域都具有重要意义。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的某些机械性能。由于碳纳米管之间的负载转移不足，纯的碳纳米管网络在机械上是脆弱的，但它可以通过分子钳来加强。这些夹子是在水溶液中形成的，但可以在化学上稳定下来，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，以形成稳定的接头，同时保留重要的开孔结构。这个项目要回答的关键问题是，单个关节的性质如何影响材料的宏观性质，这些性质可以通过分子模拟进行研究。由于分子模拟无法达到宏观水平，因此将开发一种多尺度方法来实现这一点。材料的宏观性能将基于单个关节的属性进行预测，这些属性最终与形成关节的单个分子的属性相关联。更雄心勃勃和更具挑战性的第二个目标是建立反向链接，并试图回答这样一个问题，即哪些分子将提供所需的联合属性来获得目标宏观属性。

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.