Zheng Jie, Lennon Erin M, Tsao Heng-Kwong, Sheng Yu-Jane, Jiang Shaoyi
Department of Chemical Engineering, University of Washington, Seattle, Washington 98195, USA.
J Chem Phys. 2005 Jun 1;122(21):214702. doi: 10.1063/1.1908619.
In this work, we report a dual-control-volume grand canonical molecular dynamics simulation study of the transport of a water and methanol mixture under a fixed concentration gradient through nanotubes of various diameters and surface chemistries. Methanol and water are selected as fluid molecules since water represents a strongly polar molecule while methanol is intermediate between nonpolar and strongly polar molecules. Carboxyl acid (-COOH) groups are anchored onto the inner wall of a carbon nanotube to alter the hydrophobic surface into a hydrophilic one. Results show that the transport of the mixture through hydrophilic tubes is faster than through hydrophobic nanotubes although the diffusion of the mixture is slower inside hydrophilic than hydrophobic pores due to a hydrogen network. Thus, the transport of the liquid mixture through the nanotubes is controlled by the pore entrance effect for which hydrogen bonding plays an important role.
在本研究中，我们报告了一项双控制体积巨正则分子动力学模拟研究，该研究针对水和甲醇混合物在固定浓度梯度下通过不同直径和表面化学性质的纳米管的传输情况。选择甲醇和水作为流体分子，因为水代表强极性分子，而甲醇介于非极性和强极性分子之间。将羧酸（-COOH）基团锚定在碳纳米管内壁上，将疏水表面转变为亲水表面。结果表明，尽管由于氢键网络，混合物在亲水性孔内的扩散比在疏水性孔内慢，但混合物通过亲水性管的传输速度比通过疏水性纳米管的速度快。因此，液体混合物通过纳米管的传输受孔入口效应控制，其中氢键起着重要作用。
