摘要
基于分子动力学(MD)模拟方法,建立了碳纳米管/硫化天然橡胶复合材料体系模型,采用ReaxFF势函数,模拟了不同碳纳米管(CNT)含量的复合材料的拉伸过程.通过计算复合材料体系的自由体积分数、均方位移及回转半径,分析了材料基本微观性质和碳纳米管团聚的机制,计算结果与实验相符.通过碳纳米管与硫化天然橡胶界面能的计算,发现在加载过程中系统总势能的变化主要由硫化天然橡胶基体引起,其中非键能起主导作用;碳纳米管由于其自身力学性能较好,且与天然橡胶分子链相互作用产生界面能,导致材料力学性能提升,材料的屈服应力随碳纳米管含量的增加而显著升高.
Carbon nanotube/natural rubber composite has excellent mechanical properties and has become a research hotspot in many fields.One of the main obstacles is to use traditional experimental methods to conduct experimental research on carbon nanotube/natural rubber composite at the atomic level.In this paper,based on the molecular dynamics(MD)simulation,the effects of different carbon nanotube contents on tensile properties of vulcanized natural rubber composites at the atomic scale were investigated.A carbon nanotube(CNT)/vulcanized natural rubber composite system was established.The ReaxFF potential function was used to simulate the tensile process of composites with different carbon nanotube contents.The basic microscopic properties of the material and the agglomeration mechanism of carbon nanotubes were investigated based on the analysis of free volume fraction,mean square displacement and radius of gyration for the composite system.The calculation results are consistent with the experimental ones.It was confirmed that the van der Waals force between carbon nanotubes is the primary cause of the agglomeration of carbon nanotubes.Based on this,the optimum content of carbon nanotube-reinforced natural rubber matrix can be accurately predicted.By calculating the interfacial energy between carbon nanotubes and natural rubber,it is found that the change of the total potential energy of the system during loading is mainly caused by the vulcanized natural rubber matrix,in which the non-bonding energy composed of van der Waals and Coulomb energy plays a leading role.Due to the good mechanical properties of carbon nanotubes and the interfacial energy generated by the interaction with natural rubber molecular chain,the mechanical properties of materials are improved,and the yield strength of materials increases significantly with the increase in carbon nanotube content.The research in this paper proposes an effective scheme for the combination of Materials Studio(MS)software with LAMMPS for molecular dynamics simulation of composite materials.The vulcanization script can make the rubber structure model more realistic,and provides theoretical support for the application of carbon nanotube/natural rubber composite in sensors,tires and other fields.
作者
闫宏远
杨洋
郭荣鑫
范正明
Hongyuan Yan;Yang Yang;Rongxin Guo;Zhengming Fan(Yunnan Key Laboratory of Disaster Reduction in Civil Engineering,Faculty of Civil Engineering and Mechanics,Kunming University of Science and Technology,Kunming,650500)
出处
《固体力学学报》
CAS
CSCD
北大核心
2023年第2期222-231,共10页
Chinese Journal of Solid Mechanics
基金
国家自然科学基金项目(11962009)资助
关键词
天然橡胶
碳纳米管
分子动力学模拟
力学性能
界面能
natural rubber
carbon nanotubes
molecular dynamics
mechanical property
interfacial energy
