Morco Stephanie R, Jensen Brian D, Bowden Anton E
Brigham Young University, Department of Mechanical Engineering 350 Engineering Building Provo UT 84602 USA
RSC Adv. 2022 Jan 12;12(4):2115-2122. doi: 10.1039/d1ra07243a.
A morphological study of the micro-scale defects induced by growing a carbon-infiltrated carbon nanotube (CICNT) forest on concave substrates was conducted. Two CICNT heights (roughly 60 μm and 400 μm) and 4 curvatures (1-4 mm ID) were studied in order to test the geometric limitations. Defects were categorized and quantified by scanning electron microscopy (SEM) of the tops and cross-sections. These deformities were categorized as increased roughness on the top surface, a corrugated (also called wavy or rippled) forest, a curved forest, an inside crevice where the forest separates, and increased forest density on the top surface. Roughness increased nearly 3-fold with the taller forest heights no matter the substrate curvature. Due to the geometric limitations of CICNT height and substrate curvature, all other microscale defects were significantly more present on samples with a small radius of curvature and a tall CICNT forest ( < 0.05). These buckling and warping types of defects were attributed to the increase in circumferential compression as the forest grows as well as the van der Waals interactions between the nanotubes. Because the fabrication process for CICNT involves growing a CNT forest and then infiltrating it with pyrolytic carbon, this work may be applicable to other CNT forests on concave substrates within these forest heights and substrate curvatures.
对在凹形衬底上生长碳渗透碳纳米管（CICNT）森林所诱导的微观尺度缺陷进行了形态学研究。研究了两种CICNT高度（约60μm和400μm）和4种曲率（内径1 - 4mm），以测试几何限制。通过对顶部和横截面的扫描电子显微镜（SEM）对缺陷进行分类和量化。这些变形被分类为顶表面粗糙度增加、波纹状（也称为波浪状或涟漪状）森林、弯曲森林、森林分离处的内部裂缝以及顶表面森林密度增加。无论衬底曲率如何，粗糙度随着森林高度增加近3倍。由于CICNT高度和衬底曲率的几何限制，所有其他微观尺度缺陷在曲率半径小且CICNT森林高的样品上显著更多（<0.05）。这些屈曲和翘曲类型的缺陷归因于随着森林生长圆周压缩的增加以及纳米管之间的范德华相互作用。因为CICNT的制造过程包括生长碳纳米管森林然后用热解碳渗透，这项工作可能适用于这些森林高度和衬底曲率范围内凹形衬底上的其他碳纳米管森林。
