College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Nankai University, Tianjin, China.
Environ Toxicol Chem. 2012 Jan;31(1):100-7. doi: 10.1002/etc.713. Epub 2011 Nov 8.
Understanding the adsorptive interactions between organic contaminants and carbon nanotubes (CNTs) is critical to both environmental applications and risk management of CNTs. The objective of the present study was to understand how transitional metal ions with strong complexing capabilities might affect the adsorption of hydroxyl- and amino-substituted aromatics to surface O-functionality-rich single-walled CNTs (O-SWNT) and N-functionality-rich single-walled CNTs (N-SWNT). Adsorption of 2,4-dichlorophenol, pentachlorophenol, and 1-naphthylamine to O-SWNT and N-SWNT can be significantly enhanced in the presence of Cu(II) (50 mg/L), whereas adsorption of 1,2-dichlorobenzene is essentially unaffected. The most likely mechanism for the Cu-enhanced adsorption is that Cu(II) serves as a bridging agent between organic solutes and the functional groups on CNT surfaces. For the adsorption of 1-naphthylamine to N-SWNT, an additional mechanism might be possible; that is, the complexation of Cu(II) with the N-functional groups of N-SWNT can change these groups from strong Lewis bases to Lewis acids and thereby significantly enhance adsorption via the mechanism of Lewis acid-base interactions. In addition, adsorption of Cu(II) can be significantly enhanced by the adsorption of organic cosolutes.
理解有机污染物与碳纳米管 (CNT) 之间的吸附相互作用对于 CNT 的环境应用和风险管理都至关重要。本研究的目的是了解具有强络合能力的过渡金属离子如何影响羟基和氨基取代芳烃在富含表面 O 官能团的单壁 CNT (O-SWNT) 和富含 N 官能团的单壁 CNT (N-SWNT) 上的吸附。在 50mg/L 的 Cu(II) 存在下，2,4-二氯苯酚、五氯苯酚和 1-萘胺对 O-SWNT 和 N-SWNT 的吸附可以显著增强，而 1,2-二氯苯的吸附基本不受影响。Cu 增强吸附的最可能机制是 Cu(II) 充当有机溶质与 CNT 表面官能团之间的桥接剂。对于 1-萘胺在 N-SWNT 上的吸附，可能存在另一种机制；也就是说，Cu(II) 与 N-SWNT 的 N 官能团的络合可以使这些基团从强路易斯碱转变为路易斯酸，从而通过路易斯酸碱相互作用的机制显著增强吸附。此外，通过吸附有机共溶剂，Cu(II) 的吸附可以显著增强。
