Effect of surface modification on single-walled carbon nanotube retention and transport in saturated and unsaturated porous media.
Effect of surface modification on single-walled carbon nanotube retention and transport in saturated and unsaturated porous media.
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DOI：
10.1016/j.jhazmat.2012.09.003
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发表时间：
2012-11
影响因子：
13.6
通讯作者：
Yuan Tian;B. Gao;V. Morales;Y. Wang;Lei Wu
中科院分区：
文献类型：
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作者：
Yuan Tian;B. Gao;V. Morales;Y. Wang;Lei Wu
研究了氧化、表面活性剂包覆和腐殖酸包覆等不同表面改性方法对单壁碳纳米管（SWNT）稳定性及其在多孔介质中流动性的影响。表征和稳定性研究表明，三种表面改性方法都是有效的，在水溶液中的单壁碳纳米管的增溶和稳定。填充砂柱实验表明，尽管3种表面处理方法对单壁碳纳米管在柱中的滞留和迁移效果不同，但改性后的单壁碳纳米管均具有高度的移动的性。与其他两种表面改性方法相比，腐殖酸包覆法引入的单壁碳纳米管的流动性最高。虽然在多孔介质中的水分含量的减少可以促进保留的表面改性的单壁碳纳米管在一些砂柱，从鼓泡塔实验的结果表明，只有氧化的单壁碳纳米管保留在不饱和多孔介质中通过空气-水界面上的附件。其他机制，如粮食表面附着和薄水膜应变也可能是负责单壁碳纳米管在不饱和多孔介质中的保留。采用对流-弥散模型成功地模拟了表面改性单壁碳纳米管在多孔介质中的滞留和迁移实验数据。
This work investigated the effect of different surface modification methods, including oxidization, surfactant coating, and humic acid coating, on single-walled carbon nanotube (SWNT) stability and their mobility in granular porous media under various conditions. Characterization and stability studies demonstrated that the three surface modification methods were all effective in solubilizing and stabilizing the SWNTs in aqueous solutions. Packed sand column experiments showed that although the three surface medication methods showed different effect on the retention and transport of SWNTs in the columns, all the modified SWNTs were highly mobile. Compared with the other two surface modification methods, the humic acid coating method introduced the highest mobility to the SWNTs. While reductions in moisture content in the porous media could promote the retention of the surface modified SWNTs in some sand columns, results from bubble column experiment suggested that only oxidized SWNTs were retention in unsaturated porous media through attachment on air–water interfaces. Other mechanisms such as grain surface attachment and thin-water film straining could also be responsible for the retention of the SWNTs in unsaturated porous media. An advection–dispersion model was successfully applied to simulate the experimental data of surface modified SWNT retention and transport in porous media.