Ionic liquids (ILs) have been largely investigated for their properties that make them good candidates for "environment friendly" applications. Moreover, the wide variety of possible anions/cations and/or mixing with other liquids, such as water, alcohols or different ILs, allows the fine tuning of their physicochemical properties, such as viscosity, electrical conductivity, melting point, and glass transition temperature, aiming to match specific operating conditions. In particular, the influence of the added water on the ionic liquid properties have been studied in recent years. Indeed, the knowledge of the molecular state of water and a deep understanding of the interactions between ILs and water is strategic in view of their many applications, ranging from extractive distillation or liquid-liquid extraction, synthesis and solution to their use in electrochemical devices like fuel cells. In addition, this knowledge is also needed to control the water effects for the open air use of ILs.
The main goal of the present project is the study of the effect of controlled water addition on the physical properties of selected hydrophilic ILs in order to establish the phase diagram of the hydrated materials. Indeed, the effects of water on the occurring of phase transitions in ILs have been less studied than the alteration induced in the conductive or dynamic properties, and the modifications induced by water on the structure of ILs are still not fully understood.
The synergic exploitation of experimental (Raman/IR spectroscopy, X-ray/neutron diffraction, differential scanning calorimetry) and computational tools will guarantee a robust understanding of the structural and microscopic properties of these mixed systems. The proposing team has well-established reputation in the proposed topic and the exploitation of the different techniques for such a task that guarantees the success of the proposed research plan.
The project aims to study the effect of water on the phase diagram of hydrophilic ionic liquids and on their structure in the different phases of such a diagram. Moreover also the involvement of water in the different phase transition will be considered, with a particular focus on the water state and its interaction with the ions composing the liquids. In particular we will exploit a wide range of temperature and pressure providing information about the effects of the interaction between water and ILs on the temperature/pressure behavior of the mixtures; moreover we will also target the different effects of water taken from the atmosphere and of water added in a larger amount.
This research thus addresses one of the hottest topic in the field of ionic liquids, both providing fundamental knowledge, since the structural behavior of mixed systems of ILs and water at increasing water content has been less studied compared to other conductive and dynamic properties, and impacting the use of ILs in application where it is necessary to determine the evolution of their properties through hydration. To reach this goal we will combine different experimental techniques (Raman/IR spectroscopy, X-ray/neutron scattering, differential scanning calorimetry ) and computational approaches, which in turns needs a synergetic collaboration between the proposing partners. Indeed, researchers involved in the project have well established reputation in the field of ionic liquids and in the use of the proposed techniques, as well as a well established ability to pursue a successful research program on ILs, as proved by the publication records, which guarantees the success of the proposed research and supports the request for founding our project. The results of the proposed research will be presented in high impact journals and at a topic-specific Conferences.