浮动催化CVD法CNTs膜及CNTs膜/环氧复合材料拉伸特性

针对浮动催化化学气相沉积(CVD)法制备的碳纳米管(CNTs)膜,首先采用红外光谱表征分析了包覆在CNTs表面的无定形物质的组成,然后分别采用热处理和酸洗处理方法,考察了CNTs膜中无定形物和残留Fe催化剂对CNTs膜拉伸取向行为的影响。结果表明:采用CVD法制备的CNTs膜中CNTs表面无定形物为含氧或烷烃、烯烃类低聚物,可通过350℃有氧热处理基本去除。该CNTs膜的牵伸取向重排行为受组成影响显著,CNTs表面的低聚物可增强CNTs的管间黏结作用,Fe催化剂颗粒成为CNTs网络结构的交联结点,两者均有利于提高CNTs的取向程度和聚并成束的尺寸,进而提高CNTs膜的拉伸稳定性和断裂韧性。牵伸取向后CNTs膜与环氧树脂溶液的浸润性提高,其CNTs膜/环氧复合材料的拉伸强度和模量达到1228MPa和94.5GPa,相比初始无规CNTs膜/环氧复合材料的分别提高了337%和729%。 

Tensile performance of floating catalyst CVD CNTs film and CNTs film/epoxy composites

Based on carbon nanotubes (CNTs) film prepared by floating catalyst chemical vapor deposition (CVD) method, the component of amorphous substance coating on CNTs surface was firstly analyzed by infrared spectroscopy. Moreover, heat-treatment and acid-treatment were used separately to investigate the effects of amorphous substance and residual Fe catalyst in CNTs film on tensile orientation behavior of CNTs film. The results indicate that the amorphous substances on surface of CNTs in CNTs film prepared by CVD method are oligomer containing oxygen, alkane or olefin groups, which can be removed through 350℃ treatment in air. The component of CNTs film can significantly impact the aligning and rearranging behavior of CNTs film. The oligomer on surface of CNTs film tends to enhance the interaction between CNTs and Fe catalyst particle serves as crossing junctions of the CNTs network, which both improve the CNTs orientation degree and the size of bundles, and hence increase the tensile stability and breakage toughness of the CNTs film. After stretching, the CNTs film has better wettability with epoxy solution, and the tensile strength and modulus of CNTs film/epoxy composites reach 1 228 MPa and 94.5 GPa respectively, which are increased by 337% and 729% than the initial random CNTs film/epoxy composites.