应变对非常规间距双壁碳纳米管层间摩擦的影响

Effect of strain on the interlayer friction behavior of double-walled carbon nanotubes with abnormal interlayer distances

为揭示低维纳米材料的摩擦规律,并对摩擦过程进行有效调控,利用分子动力学模拟方法研究轴向拉伸应变对不同层间距双壁碳纳米管层间摩擦行为的影响机理。模拟结果显示,与常规间距(层间距d=0.34 nm)双壁碳管相比,非常规间距(d<0.34 nm)的碳管层间摩擦行为受应变的影响更显著,即非常规间距双壁碳管层间摩擦力随着应变的增加明显降低,而常规间距双壁碳管层间的摩擦变化相对较小。分析发现,应变作用使非常规间距双壁碳纳米管较强的层间范德华作用逐渐变弱,导致层间剪切阻力降低、摩擦力减小。研究表明,应变工程可有效调控非常规间距碳纳米管层间的摩擦行为,结果对深入理解低维纳米材料摩擦行为具有重要意义。

In order to reveal the friction mechanism of low-dimensional nanomaterials,and effectively regulate the friction process,the interlayer friction of coaxial double-walled carbon nanotubes(DWNTs)with different interlayer distances under axial tension was studied by molecular dynamics simulations.The simulation results show that the friction behavior of the abnormal DWNTs is quite different from that of a normal DWNT(interlayer distances d=0.34 nm).The interlayer friction force of the abnormal DWNTs(d<0.34 nm)could be reduced by increasing the tensional strain,but the friction force changes between the layers of the normal DWNT are relatively small.It is found that the interlayer van der Waals interaction of the abnormal DWNTs decreases gradually with increasing the strain,which leads to an obvious decrease in the interlayer resistance and the interlayer friction force.The research indicates that the interlayer frictional behavior of abnormal DWNTs can be effectively regulated by strain engineering.The results are of great significance for further understanding the frictional behavior of low-dimensional nanomaterials.