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DNA分子包裹的碳纳米管
Carbon nanotubes wrapped by DNA molecules |
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| 课程网址: |
http://videolectures.net/slonano07_enyashin_cnu/
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| 主讲教师: |
Andrey Enyashin
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| 开课单位: |
德累斯顿工业大学
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| 开课时间: |
2008-02-12
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| 课程语种: |
英语
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| 中文简介: |
碳纳米管（CNT）和核酸的复合物可以通过两种组分的尺寸特定匹配，也可以将非极性CNT固定在极性基材（例如氧化物）上，从而充分利用CNT在纳米电子器件中的潜力。核酸分子包裹的CNT还允许CNT转移到水溶液中，并具有使用色谱方法进行半径和长度分离的性能。在本工作中，首次使用分散校正的量子力学密度功能紧密结合方法研究了均聚物单链DNA分子（CNT @ DNA）包裹的单壁碳纳米管的缔合体的稳定性和电子性质。 DFTB）。建立了取决于纳米管半径的CNT @ DNA形成能的现象学模型，该模型表明，通过少量（而非单个）DNA链修饰CNT会导致CNT @ DNA的高水溶性。发现基于嘧啶的DNA包裹CNT更有效，而基于嘌呤的DNA包裹对半径变化更敏感。 CNT @ DNA复合物的状态密度接近“自由”组分的状态密度的叠加，并且还有费米能级以下的其他状态。杂合CNT @ DNA系统中的带隙取决于“游离” DNA和CNT的费米能级之间的竞争。在一些特定情况下（多胞嘧啶DNA和手性金属CNT的复合物），观察到了从DNA到CNT的大量电荷转移，同时增加了CNT @ DNA形成能。
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| 课程简介: |
Complexes of carbon nanotubes (CNTs) and nucleic acids allow fully exploit the potential of the CNTs in nanoelectronic devices, both by a size-specific matching of the two components and by the possibility to anchor also non-polar CNTs on the polar substrates such as oxides. The wrapping CNTs by the nucleic acid molecules allow also a transfer of CNTs into water solutions and a performance for their radii and lengths separation using chromatographical methods. In the present work for the first time the stability and electronic properties of the associates of the single-walled carbon nanotubes wrapped by homopolymeric single-stranded DNA molecules (CNT[url]) are studied using a dispersion corrected modification of quantum mechanical density-functional tight-binding method (DFTB). A phenomenological model of the CNT[url] formation energy depending on the nanotube radii is developed, which shows that the decoration of a CNT by a few (not single) DNA chains leads to a high water solubility of CNT[url]. Pyrimidine-based DNAs are found to be more effective to wrap the CNTs, whereas purine-based DNAs are in wrapping more sensitive to the change of radii. The densities-of-states of the CNT[url] complexes are close to the superposition of those of the “free” components with some additional states below Fermi level. The band gap in a hybrid CNT[url] system is determined by the competition between the Fermi levels of the “free” DNA and CNT. In a few specific cases (complexes of polycytosine-DNA and a chiral metallic CNT) a considerable charge transfer from the DNA to the CNT was observed, combined with an additional gain in the CNT[url] formation energy.
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| 关 键 词: |
碳纳米管; 核酸; 色谱方法
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| 课程来源: |
视频讲座网
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| 最后编审: |
2019-09-21：cwx
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| 阅读次数: |
85
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图 书 馆