Synthesis and thermophysical properties of two new protic long-chain ionic liquids with the oleate anion

This work reports the synthesis of 2-hydroxy ethylammonium oleate and bis(2-hydroxy ethyl)ammonium oleate ionic liquids, which have a long aliphatic chain as well as the study of some of their physical properties, in particular the effect of temperature on their density, speed of sound, viscosity, and refractive index. 1H and 13C NMR spectra were used to characterize the chemical structure of the species in concordance with FT-IR spectra. DOSY NMR spectra were used to determine the self-diffusion coefficients of 2-hydroxy ethylammonium oleate ionic liquid, which were consistent with the formation of a lamellar or micellar liquid crystal phase; due the similar structure, a similar aggregation in the bis(2-hydroxy ethyl)ammonium oleate ionic liquid it is expected.