中文摘要：

利用分子动力学模拟方法，对比考察了平衡条件、外压作用、梯度电场作用下，摩尔比为1：1的甲醇-水混合溶液在纳米碳管（CNT）中的静态结构以及输运行为．研究发现：在平衡体系与外压作用下，纳米碳管内甲醇与水呈现出明显的不混溶现象，甲醇主要分布于管壁附近，水分子主要分布于纳米碳管轴心附近：而在梯度电场作用下．纳米碳管由疏水性向亲水性转变，更多的水分子分布于管壁，导致纳米碳管内甲醇一水的不混溶现象消失．另一方面，在外压作用下，纳米碳管内甲醇与水呈现单向移动：而在梯度电场下，甲醇与水呈现快速的双向移动，其流通量较相应外压作用体系高出近一个数量级，但由于双向的流通量大小相近，导致净流通量与外压作用下的净流通量差异不大．

英文摘要：

Molecular dynamics simulations of a methanol-water mixture （molar ratio 1：1） were performed to determine the differences among the structural and transport properties in three carbon nanotube （CNT） systems： an equilibrium system, a system with an external pressure, and a system with a gradient electric field. The simulations showed that in both the equilibrium system and the system with an external pressure, the methanol-water mixture is clearly immiscible in the CNTs, with the water molecules distributed mainly around the tube axis, and the methanol molecules located near the tube wall; however, in the system with a gradient electric field, the hydrophobic CNTs become hydrophilic, and the phenomenon of methanol-water separation disappears. In contrast, unlike the unidirectional transport observed in the system with an external pressure, the particles move in two directions in the system with a gradient electric field, with a flow one order of magnitude larger than that in the corresponding external pressure system. However, in the system with a gradient electric field, the net flux is small, because the flows for the two directions are similar. There is thus a small flux difference between the system with an external pressure and the system with a gradient electric field.