Adibnia Vahid, Mirbagheri Marziye, Latreille Pierre-Luc, De Crescenzo Gregory, Rochefort Dominic, Banquy Xavier
Faculty of Pharmacy , Université de Montréal , 2900 Édouard-Montpetit , Montreal H3C 3J7 , Canada.
Department of Chemical Engineering , Ecole Polytechnique de Montreal , P.O. Box 6079, Succursale Centre-Ville, Montreal H3C 3A7 , Canada.
Langmuir. 2019 Dec 3;35(48):15585-15591. doi: 10.1021/acs.langmuir.9b02011. Epub 2019 Aug 2.
Using the surface force apparatus (SFA), the interaction forces between mica surfaces across ionic liquid (IL) solutions are studied. The IL solution, 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide in propylene carbonate solvent, is used at different concentrations to elucidate the ions' conformation at the interface from the analysis of short-range structural forces. A direct correlation between the ion layer thickness at the interface and the IL molar fraction in the solution is observed, suggesting conformational changes relative to the ion packing density. In addition, effects of large microscopic and macroscopic water domains at the interface are investigated. The microscopic water domains induced significant adhesion at contact because of the long-range capillary forces, which are found to depend on solvent concentration. The macroscopic water domains entirely cover the interaction area, ensuring that the long-range interfacial interactions occur entirely across the aqueous electrolyte solution with dissolved IL ions as the electrolyte. These results help elucidate the interfacial interactions in IL-charged solid interfaces with practical importance in green energy storage, catalysis, and lubrication.
使用表面力仪（SFA），研究了云母表面在离子液体（IL）溶液中的相互作用力。所使用的IL溶液是在碳酸丙烯酯溶剂中的1-己基-3-甲基咪唑鎓双（三氟甲基磺酰）亚胺，通过分析短程结构力，在不同浓度下用于阐明界面处离子的构象。观察到界面处离子层厚度与溶液中IL摩尔分数之间存在直接相关性，表明相对于离子堆积密度存在构象变化。此外，还研究了界面处大的微观和宏观水区域的影响。微观水区域由于长程毛细作用力在接触时引起显著的粘附，发现这种力取决于溶剂浓度。宏观水区域完全覆盖相互作用区域，确保长程界面相互作用完全通过含有溶解的IL离子作为电解质的水性电解质溶液发生。这些结果有助于阐明IL带电固体界面中的界面相互作用，这在绿色储能、催化和润滑方面具有实际重要性。
