Density measurement of size selected multiwalled carbon nanotubes by mobility-mass characterization
Density measurement of size selected multiwalled carbon nanotubes by mobility-mass characterization
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DOI：
10.1016/j.carbon.2009.01.011
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发表时间：
2009-04-01
期刊：
影响因子：
10.9
通讯作者：
Zachariah, M. R.
中科院分区：
文献类型：
--
作者：
Kim, S. H.;Mulholland, G. W.;Zachariah, M. R.
我们采用气相颗粒迁移率和质量方法相结合，对气相生长的碳纳米管（CNT）进行了首次绝对密度测量。该方法将串联差分迁移率分析仪和气溶胶颗粒质量分析仪串联起来，实现碳纳米管的电迁移率分类和质量分类两步。在第一个迁移率分类步骤中，通过脉冲激光烧蚀产生单分散催化颗粒流。这些迁移率分类的催化剂促进了碳纳米管的气溶胶生长，然后直接进入第二个电迁移率分类步骤，该步骤允许对直径控制的碳纳米管的长度进行分类。这些按直径和长度分类的碳纳米管最终被引入气溶胶颗粒质量分析仪中以测量其质量分布。我们发现，对于直径接近15 nm和接近22 nm的两组不同的CNT，CNT的凝聚相密度为1.74 +/- 0.16 g/cm(3)。该值比石墨低（约 3 西格玛），比炭黑密度测量的平均值低约 1 西格玛。 (C) 2009 Elsevier Ltd. 保留所有权利。
We employ a combination of gas phase particle mobility and mass methods to make the first absolute density measurement of gas phase grown carbon nanotubes (CNTs). The approach combines a tandem differential mobility analyzer and aerosol particle mass analyzer in series to achieve two steps of electrical mobility classifications of the CNTs and one of mass classification. In the first mobility classification step a stream of monodisperse catalytic particles was produced by pulsed laser ablation. These mobility-classified catalysts seeded the aerosol growth of CNTs, where were directly passed to a second electrical mobility classification step which allows classification of the diameter-controlled CNTs in length. These diameter- and length-classified CNTs were finally introduced into the aerosol particle mass analyzer to measure their mass distribution. We found that the condensed phase density of CNTs was 1.74 +/- 0.16 g/cm(3) for two different groups of CNTs with diameters of similar to 15 and similar to 22 nm. This value is lower (about 3 sigma) than for graphite, and about 1 sigma lower than the average value for density measurements for carbon black. (C) 2009 Elsevier Ltd. All rights reserved.