Hubbard Joel, Isik Tugba, Ansell Troy Y, Ortalan Volkan, Luhrs Claudia
Mechanical and Aerospace Engineering Department, Naval Postgraduate School, Monterey, CA 93943, USA.
Materials Science and Engineering Department, University of Connecticut, Storrs, CT 06269, USA.
Nanomaterials (Basel). 2021 Aug 25;11(9):2168. doi: 10.3390/nano11092168.
Epoxy resins for adhesive and structural applications are widely employed by various industries. The introduction of high aspect ratio nanometric conductive fillers, i.e., carbon nanotubes, are well studied and are known to improve the electrical properties of the bulk material by orders of magnitude. This improved electrical conductivity has made carbon nanotube-based nanocomposites an attractive material for applications where their weight savings are at a premium. However, the analytical methods for validating carbon nanotube (CNT) nanofiller dispersion and for assuring that the properties they induce extend to the entire volume are destructive and inhibited by poor resolution between matrix and tube bundles. Herein, rare-earth oxide nanoparticles are synthesized on CNT walls for the purpose of increasing the contrast between their network and the surrounding matrix when studied by imaging techniques, alleviating these issues. The adherence of the synthesized nanoparticles to the CNT walls is documented via transmission electron microscopy. The crystalline phases generated during the various fabrication steps are determined using X-ray diffraction. Deep ultraviolet-induced fluorescence of the Eu:YO-CNT nanostructures is verified. The impacts to nanocomposite electrical properties resulting from dopant introduction are characterized. The scanning electron microscopy imaging of CNT pulp and nanocomposites fabricated from untreated CNTs and Eu:YO-CNTs are compared, resulting in improved contrast and detection of CNT bundles. The micro-CT scans of composites with similar results are presented for discussion.
用于粘合剂和结构应用的环氧树脂被各行各业广泛使用。高长径比的纳米导电填料（即碳纳米管）的引入已得到充分研究，并且已知其可将块状材料的电性能提高几个数量级。这种改善的导电性使基于碳纳米管的纳米复合材料成为一种有吸引力的材料，适用于对重量减轻要求很高的应用。然而，用于验证碳纳米管（CNT）纳米填料分散性以及确保它们所诱导的性能扩展到整个体积的分析方法具有破坏性，并且受到基质和管束之间分辨率差的限制。在此，为了在通过成像技术研究时增加其网络与周围基质之间的对比度，从而缓解这些问题，在碳纳米管壁上合成了稀土氧化物纳米颗粒。通过透射电子显微镜记录合成的纳米颗粒与碳纳米管壁的附着情况。使用X射线衍射确定在各个制造步骤中产生的晶相。验证了Eu:YO-CNT纳米结构的深紫外诱导荧光。表征了掺杂剂引入对纳米复合材料电性能的影响。比较了由未处理的碳纳米管和Eu:YO-碳纳米管制成的碳纳米管纸浆和纳米复合材料的扫描电子显微镜图像，从而提高了对比度并检测到了碳纳米管束。展示了具有类似结果的复合材料的微型计算机断层扫描图像以供讨论。
