Vo Minh D, Papavassiliou Dimitrios V
School of Chemical, Biological, and Materials Engineering, University of Oklahoma, Norman, OK 73019-1004, USA.
Molecules. 2016 Apr 15;21(4):500. doi: 10.3390/molecules21040500.
Dissipative particle dynamics (DPD) simulations were utilized to investigate the ability of sodium dodecyl sulfate (SDS) to adsorb inside a single-walled, arm-chair carbon nanotube (SWCNT), as well as the effect of surfactant on the properties of water inside the SWCNT. The diameter of the SWCNT varied from 1 to 5 nm. The radial and axial density profiles of water inside the SWCNTs were computed and compared with published molecular dynamics results. The average residence time and diffusivity were also calculated to show the size effect on mobility of water inside the SWCNT. It was found that nanotubes with diameter smaller than 3 nm do not allow SDS molecules to enter the SWCNT space. For larger SWCNT diameter, SDS adsorbed inside and outside the nanotube. When SDS was adsorbed in the hollow part of the SWCNT, the behavior of water inside the nanotube was found to be significantly changed. Both radial and axial density profiles of water inside the SWCNT fluctuated strongly and were different from those in bulk phase. In addition, SDS molecules increased the retention of water beads inside SWCNT (d ≥ 3nm) while water diffusivity was decreased.
采用耗散粒子动力学（DPD）模拟研究了十二烷基硫酸钠（SDS）在单壁扶手椅型碳纳米管（SWCNT）内部的吸附能力，以及表面活性剂对SWCNT内部水性质的影响。SWCNT的直径在1至5纳米之间变化。计算了SWCNT内部水的径向和轴向密度分布，并与已发表的分子动力学结果进行了比较。还计算了平均停留时间和扩散系数，以显示尺寸对SWCNT内部水迁移率的影响。结果发现，直径小于3纳米的纳米管不允许SDS分子进入SWCNT空间。对于直径较大的SWCNT，SDS吸附在纳米管内外。当SDS吸附在SWCNT的中空部分时，发现纳米管内部水的行为发生了显著变化。SWCNT内部水的径向和轴向密度分布都强烈波动，且与体相中的不同。此外，SDS分子增加了SWCNT（d≥3nm）内部水珠的保留率，同时水的扩散系数降低。
