【作者】 赵奎文； 吴慧英； 刘振宇；

【Author】 Kuiwen Zhao;Huiying Wu;Zhenyu Liu;School of Mechanical Engineering,Shanghai Jiao Tong University;

【机构】 上海交通大学机械与动力工程学院；

【摘要】 本文通过分子动力学模拟研究了不同温度下(273.15-373.15 K)水在不同内径(0.548-0.948 nm)碳纳米管内的自扩散行为,确定了水在不同内径碳纳米管内的轴向自扩散系数与温度的关系。研究表明,温度对水在纳米管内的轴向自扩散系数的影响对于不同内径的碳纳米管具有明显差异,这是由碳纳米管内水结构的差异引起的。对于内径为0.681 nm和0.820-0.905 nm的碳纳米管,当温度由373.15K降低到273.15 K时,碳纳米管内的自由液态水分子会自发形成与固体相似的有序结构,这使水在碳纳米管内的轴向自扩散系数降低了3个数量级。更多还原

【Abstract】 Self-diffusion behavior of water inside carbon nanotubes with different pore sizes(0.548-0.948 nm) over the temperature range of 273.15-373.15 K are studied by molecular dynamics simulations.The relationship between temperature and self-diffusion coefficients of water in axial direction is determined for carbon nanotubes with different inner diameters.The results demonstrate that the temperature dependence of self-diffusion coefficient of water inside carbon nanotubes is obviously different for different inner diameters,which is attribute to the difference of water structure inside carbon nanotubes.It can be found that for carbon nanotube with inner diameter of 0.681 nm and 0.820-0.905 nm,the self-diffusion coefficient decreases 3 orders of magnitude as the temperature decreases from 373.15 K to 273.15 K,which is due to the spontaneous change in water structure from free liquid state to solid-like ordered structures.更多还原