Surface structure of the mixture of 1-alkyl-3-methylimidazolium iodide and polyiodide observed by surface tension measurement and X-ray reflectivity

The mixtures of 1-alkyl-3-methylimidazolium iodide ([C(n)mim][I], n is the alkyl chain number) and iodides are promising candidates for electrolytes used in a dye-sensitized solar cell with high performance. However, thus far, the effect of surface structure on electroconductivity at the electrode surface and how to avoid the disadvantage of corroding metals or electrodes remain unclear. Thus, we investigated the surface tension and X-ray reflectivity of the mixtures to clarify the molecular arrangement at the liquid-vapor interface. It was shown that surface tension steeply decreased upon mixing iodides; polyiodides localized around the liquid-vapor interface and localization behaviors were independent on n, and the surface was hindered well by longer alkyl chains. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The research showed that the surface tension of mixtures steeply decreased upon mixing iodides, polyiodides localized around the liquid-vapor interface independently of the alkyl chain number, and longer alkyl chains effectively hindered the surface.