Multi-scale approach for prediction of electrical properties of carbon nanotube reinforced polymers

该项目旨在开发和应用一种多尺度计算方法，用于预测模拟碳纳米管增强聚合物（CNRP）的电导率，该方法考虑到原子尺度上的电荷传输机制和微观尺度上碳纳米管（CNT）的真实形态和分布。在原子尺度上，将在真实的环境条件下研究CNT/聚合物/CNT结中的电荷输运。在经典分子动力学（MD）模拟与量子力学描述的相应的电子结构的定量电荷传输数据沿着MD-轨迹的组合将被计算。电荷输运数据将通过使用粗粒跳跃模型和非平衡绿色函数（NEGF）方法获得。将在微观模拟中获得关于CNT在现实微结构中的典型对准和距离分布的输入数据，并且将对所得结进行经典原子MD模拟以平衡相关CNT/聚合物/CNT结用于电子结构和电输运分析。在微观尺度上，代表性的体积元素将分析相对于渗流行为，通过改变质量分数，分散度，定向和弯曲度的碳纳米管。基于在原子尺度上确定的接触电阻和隧穿范围，将采用有限元法（FEM）计算实际微结构的电导率。

The project aims at development and application of a multi-scale computational approach for predictive simulations of electrical conductivity in carbon nanotube reinforced polymers (CNRP), which takes into account the charge transport mechanisms on the atomistic scale and realistic morphology and distributions of carbon nanotubes (CNTs) on the microscopic scale. On the atomic scale, charge transport in CNT/polymer/CNT junctions will be investigated under real environmental conditions. In a combination of classical molecular dynamics (MD) simulations with quantum mechanical description of the respective electronic structure quantitative charge transport data along MD-trajectories will be calculated. The charge transport data will be obtained by using coarse-grained hopping models and non-equilibrium Green´s Function (NEGF) methods. The input data concerning typical alignments and distance distributions of CNTs in realistic microstructures will be obtained in microscopic simulations and the resulting junctions will be subjected to classical atomistic MD simulations to equilibrate relevant CNT/polymer/CNT junctions for electronic structure and electrical transport analyses. On the microscopic scale, representative volume elements will be analyzed with respect to the percolation behavior by varying the mass fraction, degree of dispersion, orientation and tortuosity of CNTs. Based on the contact resistances and tunneling ranges determined at the atomic scale, electrical conductivities will be calculated for realistic microstructures employing the Finite Element Method (FEM).