We present a new technology based on delayed release of perfume raw materials from new-to-the-world binary ionic liquid mixtures.

The vapour–liquid equilibria of organic molecules dissolved in ionic liquids revealed positive deviation from Raoult's law, especially with added water.

In this work, the vapour-liquid equilibria of binary and multinary systems comprising of perfume raw materials and ionic liquids have been computed using two different models: COSMO-RS, a solvation model, and UNIFAC, a group contribution method. For systems already well known in the literature, a comparison with experimental data was performed, and good agreement was observed with both models. Although UNIFAC was not applicable to nonparameterised ionic liquids, COSMO-RS proved very reliable in predicting the vapour-liquid equilibria (VLE) of solutions of perfume raw materials (PRMs) in new-to-the-world ionic liquids. This opens the door for the prediction and modelling of new formulations for novel consumer products, prior to embarking on detailed experimental investigations.

A Fourier transform infrared gas-phase method is described herein and capable of deriving the vapour pressure of each pure component of a poorly volatile mixture and determining the relative vapour phase composition for each system. The performance of the present method has been validated using two standards (naphthalene and ferrocene), and a Raoult’s plot surface of a ternary system is reported as proof-of-principle. This technique is ideal for studying solutions comprising two, three, or more organic compounds dissolved in ionic liquids as they have no measurable vapour pressures.