石墨烯碳纳米管复合结构渗透特性的分子动力学研究  

Molecular dynamics study on permeability of water in graphene-carbon nanotube hybrid structure

作　　者：张忠强[1,2,3] 李冲 刘汉伦 葛道晗[1] 程广贵[1] 丁建宁[1,2] 

机构地区：[1]江苏大学微纳米科学技术研究中心,镇江212013 [2]常州大学江苏省光伏科学与工程协同创新中心,常州213164 [3]大连理工大学工业装备结构分析国家重点实验室,大连116024

出　　处：《物理学报》2018年第5期213-220,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11472117;11372298;11672063);江苏省自然科学基金(批准号:BK20140556)资助的课题~~

摘　　要：采用经典分子动力学方法研究了压力驱动作用下水在石墨烯碳纳米管复合结构中的渗透特性.研究结果表明,水分子渗透通过石墨烯碳纳米管复合结构的渗透率明显高于石墨烯碳纳米管组合结构.水在石墨烯碳纳米管复合结构中的渗透率随着压强的升高而增大,随着电场强度的增大而减小.考虑了温度和复合结构中双碳管轴心距对水渗透性的影响规律.系统温度越高,水的渗透率越高;随着双碳管轴心距的增加,水的渗透率逐渐降低.通过计算分析水流沿渗透方向的能障分布,解释了各参数变化对水在石墨烯碳管复合结构中渗透特性的影响机理.研究结果将为基于石墨烯碳管复合结构的新型纳米水泵设计提供一定的理论依据.In this paper, the classical molecular dynamics method is used to investigate the permeability of pressure-driven water fluid in the hybrid structure of graphene-carbon nanotube（CNT）. The results indicate that the permeability of water molecules for the hybrid structure of graphene-CNT is obviously higher than that for the assembled structure of graphene-CNT. The combination between the graphene sheet and CNT in the hybrid structure is found to be a key point to improve the permeability of water molecules. Subsequently, the potential of mean force（PMF） is calculated in order to explain the influences of the combined structure on the permeabilities for the water fluid passing through both the hybrid and assembled graphene-CNT structures. The result shows that the PMF for the water molecules penetrating through the assembled structure is larger than that for the hybrid structure appreciably. It implies that the structure of the combined chemical bonds in the hybrid structure can efficiently improve the permeability of water molecules. As for the water penetrating through the hybrid structured graphene-CNT, the permeability of water increases with water pressure rising, and decreases with the electric field intensity increasing. The water molecules cannot pass through the proposed hybrid structure below a pressure threshold of 100 MPa. The permeability of water in the hybrid structure decreases with the increasing charge quantity on CNT below a threshold of 0.8 e. The PMF for water penetrating through the hybrid structure decreases with charge quantity decreasing. The results suggest that the water permeability can be controlled by regulating the water pressure and the electric field intensity. Furthermore, the influences of the temperature and the axis spacing of two CNTs in the hybrid structure on the water permeability are considered. The permeability of water in the hybrid structure increases with the increasing temperature above a threshold of 200 K. The PMF for water penetrating through the hybrid stru

关 键 词：石墨烯碳纳米管复合结构 水 渗透率 分子动力学 

分 类 号：TB383.1[一般工业技术—材料科学与工程]