The imaging mechanism, imaging depth, and parameters influencing the visibility of carbon nanotubes in a polymer matrix using an SEM
The imaging mechanism, imaging depth, and parameters influencing the visibility of carbon nanotubes in a polymer matrix using an SEM
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DOI：
10.1016/j.carbon.2010.12.069
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发表时间：
2011-05-01
期刊：
影响因子：
10.9
通讯作者：
Bauhofer, Wolfgang
中科院分区：
文献类型：
--
作者：
Li, Wenjing;Buschhorn, Samuel T.;Bauhofer, Wolfgang
使用扫描电子显微镜 (SEM) 可视化聚合物中嵌入的碳纳米管 (CNT) 已成为评估 CNT 分散性的便捷技术。该技术称为电压对比成像，不同于材料对比和形貌对比成像。通过研究碳纳米管/环氧树脂复合材料，进一步了解了电压对比成像理论。碳纳米管/环氧树脂界面上的电子俘获会产生局部电位差，从而增强图像对比度。通过在复合材料上涂覆不同厚度的聚合物薄膜，成像深度（即可以看到 CNT 的深度）被确定为高达 250 nm，并且是 SEM 加速电压的函数。发现 CNT 的可见度对 CNT 分散度和浓度以及加速电压敏感。 (C) 2011 Elsevier Ltd. 保留所有权利。
Visualization of embedded carbon nanotubes (CNTs) in polymer using a scanning electron microscope (SEM) has been established as a convenient technique to evaluate CNT dispersion. This technique is known as voltage contrast imaging and is different from material contrast and topographic contrast imaging. By investigating CNT/epoxy composites the voltage contrast imaging theory is further understood. Trapping of electrons at the CNT/epoxy interface induces a local potential difference which enhances the image contrast. By coating the composite with a polymer film of different thicknesses the imaging depth (i.e. from how deep the CNTs can be seen) is determined to be up to 250 nm, and is a function of the accelerating voltage of the SEM. Visibility of CNTs is found to be sensitive to the CNT dispersion and concentration, as well as to the accelerating voltage. (C) 2011 Elsevier Ltd. All rights reserved.