Department of Mechanical, Aerospace and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, USA.
ACS Nano. 2010 Dec 28;4(12):7415-20. doi: 10.1021/nn102529n. Epub 2010 Nov 16.
It is well established that pristine multiwalled carbon nanotubes offer poor structural reinforcement in epoxy-based composites. There are several reasons for this which include reduced interfacial contact area since the outermost nanotube shields the internal tubes from the matrix, poor wetting and interfacial adhesion with the heavily cross-linked epoxy chains, and intertube slip within the concentric nanotube cylinders leading to a sword-in-sheath type failure. Here we demonstrate that unzipping such multiwalled carbon nanotubes into graphene nanoribbons results in a significant improvement in load transfer effectiveness. For example, at ∼0.3% weight fraction of nanofillers, the Young's modulus of the epoxy composite with graphene nanoribbons shows ∼30% increase compared to its multiwalled carbon nanotube counterpart. Similarly the ultimate tensile strength for graphene nanoribbons at ∼0.3% weight fraction showed ∼22% improvement compared to multiwalled carbon nanotubes at the same weight fraction of nanofillers in the composite. These results demonstrate that unzipping multiwalled carbon nanotubes into graphene nanoribbons can enable their utilization as high-performance additives for mechanical properties enhancement in composites that rival the properties of singlewalled carbon nanotube composites yet at an order of magnitude lower cost.
已经证实，原始的多壁碳纳米管在基于环氧树脂的复合材料中提供的结构增强效果较差。造成这种情况的原因有几个，包括由于最外层的纳米管将内部纳米管与基质隔离，因此减少了界面接触面积，与交联的环氧树脂链的润湿性和界面附着力差，以及同心纳米管圆柱内的纳米管间滑动导致剑鞘式失效。在这里，我们证明了将这种多壁碳纳米管解卷成石墨烯纳米带可以显著提高负载传递效率。例如，在纳米填料的重量分数约为 0.3%时，与多壁碳纳米管相比，具有石墨烯纳米带的环氧树脂复合材料的杨氏模量增加了约 30%。同样，在重量分数约为 0.3%的纳米填料下，石墨烯纳米带的极限拉伸强度与在复合材料中具有相同纳米填料重量分数的多壁碳纳米管相比提高了约 22%。这些结果表明，将多壁碳纳米管解卷成石墨烯纳米带可以使其作为高性能添加剂用于增强复合材料的机械性能，从而与单壁碳纳米管复合材料的性能相媲美，而成本却低一个数量级。
