Dispersion of large single-walled carbon nanotube (SWCNT) bundles into individual nanotubes or small bundles and thus strengthening of the nanotube/matrix interfacial interaction are prerequisites for taking full advantage of the remarkable multifunctional properties of SWCNTs in various carbon nanotube-based composites. Noncovalent functionalization of SWCNTs is an attractive option to simultaneously achieve these conditions. Toward this end, three reactive amino-containing pyrene derivatives (AmPys) with various spacer chain lengths were synthesized. One with the longest spacer length (12 methylene units, AmPy-12) shows the highest functionalization efficiency for SWCNTs in terms of dispersibility. Systematic characterization on a SWCNT/AmPy-12 hybrid suggests that ca. 10 wt% of AmPy-12 is strongly adsorbed on SWCNTs through π–π interactions, making them steadily dispersed into individual ones and/or small bundles without noticeable change in their electronic structure. AmPy-12-functionalized SWCNTs were then used for the preparation of epoxy composites. Since the SWCNT/epoxy interface was well engineered at a molecular level by application of AmPy-12, which interacts noncovalently with SWCNT but bonds chemically to the epoxy matrix, the composite with only 0.3 wt% SWCNTs displays an increase of 54% and 27% in tensile strength and Young's modulus, respectively, over neat resin. A low electrical percolation threshold of 0.1 wt% SWCNTs and improved thermal properties were also observed.
将大尺寸单壁碳纳米管(SWCNT)束分散成单个纳米管或小束,从而增强纳米管/基体界面相互作用,是充分发挥SWCNT在各种碳纳米管基复合材料中显著多功能特性的前提。对SWCNT进行非共价功能化是同时实现这些条件的一个有吸引力的选择。为此,合成了三种具有不同间隔链长度的含
氨基的
芘衍
生物(AmPys)。其中,间隔长度最长的(12个亚甲基单位,AmPy-12)在分散性方面对SWCNT的功能化效率最高。对SWCNT/AmPy-12混合物的系统表征表明,大约10 wt%的AmPy-12通过π–π相互作用强烈吸附在SWCNT上,使它们稳定地分散成单个纳米管和/或小束,且未明显改变其电子结构。随后,利用功能化的AmPy-12制备了环氧
树脂复合材料。由于SWCNT/环氧
树脂界面在分子
水平上通过应用AmPy-12得到了良好的工程化,AmPy-12与SWCNT之间是非共价相互作用,但与环氧基体则是
化学键合,因此仅0.3 wt%的SWCNT复合材料在拉伸强度和杨氏模量上分别比纯
树脂提高了54%和27%。同时还观察到0.1 wt%细度的电导阈值和改善的热性能。