Characterizing elastic properties of carbon nanotubes/polyimide nanocomposites using multi-scale simulation
Characterizing elastic properties of carbon nanotubes/polyimide nanocomposites using multi-scale simulation
复制标题
DOI：
10.1016/j.compositesb.2009.06.003
复制
发表时间：
2010-01-01
影响因子：
13.1
通讯作者：
Chiu, Yu-Tsung
中科院分区：
文献类型：
--
作者：
Tsai, Jia-Lin;Tzeng, Shi-Hua;Chiu, Yu-Tsung
本研究旨在利用多尺度模拟方法表征碳纳米管增强聚酰亚胺纳米复合材料的弹性性能。将CNTs的空心圆柱形分子结构建模为横向各向同性固体，并结合能量等效概念通过分子力学计算确定其等效弹性特性。随后，通过h分子动力学（MD）模拟建立了CNTs/聚酰亚胺纳米复合材料的分子结构，评估了CNTs与周围聚酰亚胺之间的非键隙以及非键能，并假设归一化非键能（非键能除以CNTs的表面积）与界面相互作用的程度相关。之后。在碳纳米管和聚酰亚胺聚合物之间引入有效界面来表征非键相互作用的程度。假设界面尺寸等于非键合间隙，根据归一化非键合能量计算相应的弹性刚度。采用以聚酰亚胺为基体的等效圆柱体为碳纳米管的三相微力学模型预测了碳纳米管复合材料的弹性性能。有效间期包括在内。结果表明，基于三相模型得到的纳米复合材料的纵向模量与MD模拟结果吻合较好。此外，它们非常符合混合预测的传统规则。另一方面，在横向上，三相模型优于传统的微力学模型，因为它能够预测横向模量与纳米管半径的依赖关系。2009爱思唯尔有限公司版权所有。
This research is aimed at characterizing the elastic properties of carbon nanotubes (CNTs) reinforced polyimide nanocomposites using a multi-scale simulation approach. The hollow cylindrical molecular structures of CNTs were modeled as a transverse isotropic solid, the equivalent elastic properties of which were determined from the molecular mechanics calculations in conjunction with the energy equivalent concept. Subsequently, the molecular structures of the CNTs/polyimide nanocomposites were established through h molecular dynamics (MD) simulation, from which the non-bonded gap as well as the non-bonded energy between the CNTs and the Surrounding polyimide were evaluated It was postulated that the normalized non-bonded energy (non-bonded energy divided by surface area of the CNTs) is correlated with the extent of the interfacial interaction. Afterwards. an effective interphase was introduced between the CNTs and polyimide polymer to characterize the degree of non-bonded interaction. The dimension of the interphase was assumed equal to the non-bonded gap, and the corresponding elastic stiffness was calculated from the normalized non-bonded energy. The elastic properties of the CNT nanocomposites were predicted by a three-phase micromechanical model in which the equivalent solid cylinder of CNTs, polyimide matrix. and the effective interphase were included. Results indicated that the longitudinal moduli of the nanocomposites obtained based on the three-phase model were in good agreement with those calculated from MD simulation. Moreover, they fit well with the conventional rule of mixture predictions. On the other hand, in the transverse direction, the three-phase model is superior to the conventional micromechanical model since it is capable of predicting the dependence of transverse modulus on the radii of nanotubes. (C) 2009 Elsevier Ltd. All rights reserved.