Department of Civil & Environmental Engineering, The University of Western Ontario, London, ON, Canada.
J Colloid Interface Sci. 2013 Jan 15;390(1):96-104. doi: 10.1016/j.jcis.2012.09.034. Epub 2012 Sep 26.
Carbon nanotubes are the subject of intense research due to their unique properties: light weight, significant strength, excellent conductivity, and outstanding chemical resistance. This has led to their application in a wide variety of industries (e.g., in composite materials). As a result of their potential impact to humans and ecosystems, there is increasing interest in understanding the factors that control the transport of carbon nanotubes in the environment, and of particular interest to this study, their transport in porous media. In this work, the transport behavior of multiwall carbon nanotubes (MWCNTs) is investigated in sand packed column experiments. To determine the importance of MWCNT diameter, experiments were conducted using four commercially available MWCNTs. Results suggest that smaller MWCNTs are less mobile than their larger counterparts, likely due to the increase in Brownian motion leading to more MWCNT collisions with the porous media with decreasing MWCNT size. A numerical model was used to simulate observed MWCNT transport behavior and facilitate comparison with published studies. These results suggest that careful characterization of MWCNT characteristics (i.e., dimensions and initial MWCNT mass in suspension) is essential to adequately interpret observed results. Results from this study suggest that MWCNTs may be mobile under conditions expected in subsurface aquifers.
由于其独特的性质，碳纳米管是目前研究的热点：重量轻、强度大、导电性好、耐化学腐蚀性强。这使得它们在许多行业得到了广泛应用（例如，在复合材料中）。由于它们对人类和生态系统可能产生的影响，人们越来越关注控制碳纳米管在环境中迁移的因素，而本研究特别关注其在多孔介质中的迁移。在这项工作中，通过沙柱实验研究了多壁碳纳米管（MWCNT）的输运行为。为了确定 MWCNT 直径的重要性，使用了四种市售的 MWCNT 进行实验。结果表明，较小的 MWCNT 比较大的 MWCNT 迁移性差，这可能是由于布朗运动的增加导致 MWCNT 与多孔介质的碰撞随着 MWCNT 尺寸的减小而增加。使用数值模型模拟了观察到的 MWCNT 输运行为，并与已发表的研究进行了比较。这些结果表明，仔细表征 MWCNT 的特性（即尺寸和悬浮液中初始 MWCNT 的质量）对于充分解释观察到的结果至关重要。本研究的结果表明，MWCNT 在地下含水层中预期的条件下可能是可迁移的。
