X-Ray scattering and physicochemical studies of trialkylamine/carboxylic acid mixtures: nanoscale structure in pseudoprotic ionic liquids and related solutions

Citation

Kobrak, M.N.; Yager, K.G. "X-Ray scattering and physicochemical studies of trialkylamine/carboxylic acid mixtures: nanoscale structure in pseudoprotic ionic liquids and related solutions" Phys. Chem. Chem. Phys. 2018, 20 18639–18646.
doi: 10.1039/C8CP02854K

Summary

X-ray scattering is used to identify nano-structuring in a class of pseudoprotic ionic liquids

Abstract

We report the results of X-ray scattering, physical, and spectroscopic measurements on a series of water-saturated trialkylamine/carboxylic acid mixtures. The results demonstrate the existence of well-defined nanoscale structures in bulk liquid mixtures at specific acid:amine ratios. These structures are analogous to those observed in ionic liquids but are driven by the formation of a hydrogen-bonded network rather than via inter-ion Coulomb forces. The results of the physical components of this study are closely analogous to prior observations on anhydrous, low molecular weight acid/amine mixtures, but this is to our knowledge the first time these observations have been augmented by the use of X-ray scattering. The results therefore bridge the gap between early work on amine/acid mixtures and recent studies of protic and pseudoprotic ionic liquids.