Multiscale QM/MM simulations of growth process and material properties of inorganic nanotubes and nanotube composites

由碳以外的材料组成的纳米管和类似的纳米结构代表着一个有趣的新研究领域，还有许多机会尚未到来。在这个项目中，我们的目标是应用数值方法来模拟和扩散对金属二卤化物和氧化物纳米管等无机纳米管生长过程的理解。具体地说，我们将对模板生长的二氧化硅纳米管中的涂层过程以及直径小于1 nm的单壁MoS2纳米管的催化传输生长进行数值模拟。此外，我们还将研究无机单壁和多壁纳米管的力学性能，如剪切和杨氏模数以及泊松比，并研究嵌入在基质中的纳米管。我们将模拟SiO_2纳米管和BN纳米管镶嵌在SiBN陶瓷、S和SiCO玻璃中。这里的目标是为未来的应用确定近乎最佳的材料特性。为了真实地处理生长过程中的反应机理，我们将应用我们之前开发的量子力学模拟方法。为了避免有限尺寸效应和达到热力学极限，我们将在适用的情况下使用我们以前开发的分子力学方法。在一个区域分解方法中，我们将结合我们的方法，产生一个带有多能级类型耦合算子的多尺度QM/MM方法。

nanotubes and similar nanostructures composed of materials other than carbon represent an interesting new field of research with many opportunities yet to come. In this project, our goal is to apply numerical methods to simulate and proliferate understanding of the growth processes of inorganic nanotubes such as metal dichalcogenide and oxide nanotubes. Specifically, we will use numerical simulation for a coating process within template growth of SiO2-nanotubes, as well as for catalyzed transport growth for single-wall MoS2-nanotubes with a diameter less than 1 nm. Furthermore, we will investigate mechanical material properties such as shear and Young's moduli and the Poisson ratio of inorganic single- and multi-wall nanotubes, and study nanotubes embedded in a matrix. We will simulate SiO2-nanotubes and BN-nanotubes embedded in SiBN ceramic s as well as SiCO glasses. Here, the goal is to characterize almost optimal materials for future applications. In order to treat the reaction mechanisms in the growth process realistically, we will apply our previously developed quantum mechanical simulation methods. In order to avoid finite size effects and to reach thermodynamical limits, we will employ our previously developed molecular mechanical methods where applicable. Within a domain decomposition approch, we will combine our methods, resulting in a multiscale QM/MM method with a multilevel type coupling operator.