Effect of the Carbon-Nanotube Length on Water Permeability
Effect of the Carbon-Nanotube Length on Water Permeability
复制标题
碳纳米管长度对透水性的影响
DOI：
10.1088/0256-307x/24/9/069
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
Zaixing Yang
中科院分区：
文献类型：
--
作者：
Ruhong Zhou;方海平;Xiaowei Tang;Jingyuan Li;Zaixing Yang
采用分子动力学模拟方法研究了碳纳米管通道长度对水在碳纳米管中流动的影响。水流量随通道长度（~1/N2.3， N为沿纳米管轴的碳环数）衰减，比之前的连续时间随机漫步（CTRW）模型（~1/N）预测的要快得多。这种意想不到的流量衰减率被发现是由于碳纳米管内部水分子协调运动的相关性减弱所致。考虑到这一影响，提出了一种改进的CTRW模型。同时，发现不同长度CNTs内水分子的扩散常数是相对不变的，这导致了相对恒定的跳变速率。
Effect of the carbon nanotube (CNT) channel length on the water flow through the CNT is studied using molecular dynamics simulations. The water flow is found to decay with the channel length (~1/N2.3, N is the number of carbon rings along the nanotube axis), much faster than that predicted by a previous continuous-time random walk (CTRW) model (~1/N). This unexpected decay rate of flow is found to result from the weakening of the correlation of the concerted motion of the water molecules inside the CNT. An improved CTRW model is then proposed by taking into account of this effect. Meanwhile, the diffusion constant of water molecules inside CNTs with various lengths is found to be relatively invariant, which results in a relatively constant hopping rate.