碳纳米管束/聚合物复合纤维的力学行为及增强机理

项目名称： 碳纳米管束/聚合物复合纤维的力学行为及增强机理

项目编号： No.11502007

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 刘夏

作者单位： 北京工业大学

项目金额： 25万元

中文摘要： 碳纳米管(CNT)束/聚合物复合纤维是CNT纤维经聚合物溶液浸润处理形成的具有多层级结构的一维复合材料。本项目旨在结合微观实验观测与分子动力学模拟，发展CNT束/聚合物复合纤维的多尺度分析模型，研究其宏观力学行为与微观结构和界面之间的依赖关系，揭示CNT束/聚合物复合纤维的增强增韧机理。具体内容包括：建立CNT纤维和聚合物的粗粒化分子动力学模型，模拟聚合物浸润CNT纤维的过程，得到真实的CNT束/聚合物浸润界面结构和复合纤维微观网络结构，计算浸润界面沿法向和切向的张力-位移曲线；确定浸润界面的内聚力模型与参数，发展界面的内聚力单元；计算CNT束/聚合物复合纤维的拉伸力学性能，分析CNT束直径、表面结构、聚合物分子结构和分子链长等因素的影响，并实现数值模拟与实验的相互印证；分析CNT束/聚合物复合纤维的宏观力学行为与界面力学行为的关系，揭示聚合物浸润对CNT纤维的增强机理。

中文关键词： CNT纤维；聚合物浸润；粗粒化分子动力学模型；内聚力连续模型；增强机理

英文摘要： CNT-bundle/polymer composite fiber is made of a CNT fiber infiltrated with polymer. Microscopic experimental observations and molecular dynamic simulations are combined to build a multi-scale analysis model for the CNT-bundle/polymer composite fiber. The macro-scale mechanical behavior of the CNT-bundle/polymer composite fiber and its relationship with the hierarchical configuration and interface are studied. Reinforcement and toughening mechanisms of the CNT-bundle/polymer composite fiber are also revealed. The study is carried out in the following aspects: coarse grained molecular dynamic models are built for the CNT bundle and the polymer, respectively, to simulate the polymer infiltration process in CNT fiber, in order to obtain an accurate model of the infiltration interface between CNT bundle and polymer; curves of normal force versus normal distance and tangential force versus sliding distance at the interface are calculated; cohesive model and its parameters are determined from the simulation results to develop continuum model for the CNT-bundle/polymer composite fiber; tensile mechanical properties of the CNT-bundle/polymer composite fiber are calculated based on the cohesive continuum model, taking into account the effects of diameter of the CNT-bundle as well as molecular structure and chain length of the polymers, and are confirmed with experimental results; relation between macro-scale mechanical behavior of the CNT-bundle/polymer composite fiber and interfacial behavior are analyzed to reveal the reinforcement mechanism.

英文关键词： CNT fiber;polymer infiltration;coarse-grained molecular dynamic model;cohesive-zone continuum model;reinforcement mechanism