College of Chemical Engineering,State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University , Nanjing, 210009, People's Republic of China.
Langmuir. 2017 Oct 24;33(42):11658-11669. doi: 10.1021/acs.langmuir.7b02044. Epub 2017 Oct 3.
Based on our previous experimental research, we studied the absorption of CO in the ionic liquid, 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([hmim][TfN]), immobilized on TiO [rutile (110) ] with different thickness by molecular dynamics simulation. The effects of the properties (hydrophobicity and hydrophilicity) of solid interfaces were also studied with IL immobilized on graphite and TiO, respectively. We studied the influence of the thickness of IL immobilized on TiO on the absorption of CO via structural and dynamical properties. The results show that the self-diffusion coefficients of IL and CO increase as the thickness of immobilized IL decreases. And the CO absorption capacity increases as the thickness of immobilized IL decreases as well. Additionally, more CO molecules are absorbed in the region near the solid interface as the thickness of IL decreases. For IL immobilized on graphite, the self-diffusion coefficients of cations and anions are larger than that of IL immobilized on TiO with the same thickness. They are also larger than nonimmobilized cations and anions.Besides, the CO absorption capacity of IL immobilized on TiO is the largest compared with IL immobilized on graphite and nonimmobilized IL with the same thickness. From our simulation work, we try to explore the microscopic mechanism that is unexplored by experimental work, and we found the important role of IL/solid interface for CO absorption in immobilized ILs.
基于我们之前的实验研究，我们通过分子动力学模拟研究了 CO 在离子液体 1-己基-3-甲基咪唑双（三氟甲烷磺酰基）亚胺（[hmim][TfN]）中的吸收，该离子液体固定在不同厚度的 TiO2（金红石（110））上。我们还分别研究了用 IL 固定在石墨和 TiO2 上时固体界面性质（疏水性和亲水性）的影响。我们研究了 TiO2 上固定的 IL 厚度对 CO 吸收的结构和动力学性质的影响。结果表明，随着固定 IL 厚度的降低，IL 和 CO 的自扩散系数增加。并且 CO 的吸收能力随着固定 IL 厚度的降低而增加。此外，随着 IL 厚度的降低，更多的 CO 分子被吸收在靠近固体界面的区域。对于固定在石墨上的 IL，阳离子和阴离子的自扩散系数大于具有相同厚度的固定在 TiO2 上的 IL。它们也大于非固定的阳离子和阴离子。此外，与具有相同厚度的固定在石墨上的 IL 和非固定的 IL 相比，固定在 TiO2 上的 IL 的 CO 吸收能力最大。通过我们的模拟工作，我们试图探索实验工作未探索的微观机制，我们发现 IL/固体界面在固定化 IL 中 CO 吸收的重要作用。
