计算模拟掺氮单壁碳纳米管对水中芳香类有机污染物的吸附作用

发布时间：2018-03-18 21:05

本文选题：吸附　切入点：吡啶氮　出处：《大连理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：掺氮碳纳米管(N-CNTs)独特的理化性质使其在诸多领域呈现广阔的应用前景。伴随着大规模的生产和使用,N-CNTs将不可避免的被释放到环境中。进入环境中的N-CNTs与污染物发生吸附作用时,可能会改变其自身及污染物的环境行为和生态风险。因此,研究N-CNTs与水中有机污染物的吸附行为具有重要意义。目前,研究者在N-CNTs的制备、表征、电化学及生物催化等方面已经开展了大量研究,但是水中有机污染物在N-CNTs上吸附的研究却鲜有报道。此外,以往模拟碳纳米管与化合物相互作用时,多使用完美碳管作为模型,并没有考虑碳管实际的掺杂浓度和掺杂形态。因此,本研究考虑N-CNTs的实际形态,构建了不同掺杂浓度、掺杂形态的掺氮单壁碳纳米管(N-SWNTs),基于密度泛函理论,模拟水中芳香类有机化合物在N-SWNTs上的吸附作用。计算表明,氮原子掺杂的浓度和形态对N-SWNTs的稳定性和吸附能力都有一定影响。氮原子的掺入可以提高N-SWNTs对芳香类化合物的吸附效果,高浓度吡啶氮掺杂的N-SWNTs对芳香类化合物具有相对较强的吸附作用。化合物与N-SWNTs之间主要发生物理吸附,疏水作用和π-π相互作用是化合物在N-SWNTs上吸附的主要作用力,污染物的官能团可加强其与N-SWNTs之间的π-π相互作用增强吸附。本研究对N-SWNTs的生态风险评价具有一定的指导意义。
[Abstract]:Because of its unique physical and chemical properties, N-CNTs have broad application prospects in many fields. With the large-scale production and use of N-CNTs, N-CNTs will inevitably be released into the environment. Therefore, it is important to study the adsorption behavior of N-CNTs with organic pollutants in water. Electrochemical and biocatalysis have been studied extensively, but the adsorption of organic pollutants on N-CNTs in water has been seldom reported. In addition, perfect carbon tubes are used as models in simulating the interaction between carbon nanotubes and compounds in the past. Therefore, considering the actual form of N-CNTs, N-SWNTs with different doping concentration and doping form are constructed, which are based on density functional theory (DFT). The adsorption of aromatic organic compounds on N-SWNTs in water was simulated. The concentration and form of nitrogen atoms have a certain influence on the stability and adsorption ability of N-SWNTs. The addition of nitrogen atoms can improve the adsorption effect of N-SWNTs on aromatic compounds. N-SWNTs doped with high concentration of pyridine nitrogen have relatively strong adsorption on aromatic compounds. Physical adsorption occurs between N-SWNTs and N-SWNTs. Hydrophobic interaction and 蟺-蟺 interaction are the main forces of adsorption on N-SWNTs. The functional groups of pollutants can enhance the 蟺-蟺 interaction between N-SWNTs and N-SWNTs and enhance the adsorption. This study has a certain guiding significance for ecological risk assessment of N-SWNTs.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1;TQ127.11

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