Mixtures of protic ionic liquids (PIL) and polar, protic molecular liquids (MLs) are attracting great attention. Due to the ionic nature of PILs and the role of hydrogen bonding (HB) on their structure, it can be expected that such MLs will largely affect their structure. We propose to use neutron scattering at SANDALS to explore the structure of two PILs mixed with formamide derivatives with 0, 1 and 2 amino methyl groups. The corresponding change in number of donor HB sites, together with the different ML polarities, is likely to affect PILs structure. These mixtures have not been explored so far, despite their potential importance, considering that the mentioned amides are widely used organic solvents and represent an interesting mimic system for peptides and PILs-based mixtures with such MLs are likely to have interesting applications in bio-related fields.

We propose to employ the neutron Compton scattering (NCS) in the realm of ionic liquids (iL), applying it to the protiated and deuterated variants of an archetipic IL, phosporic acid (PA). PA and its solutions have one of the highest intrinsic proton conductivities among known materials, and the mechanism of this unique conductivity remains a puzzle. A recent study discovered a strong isotope effect in the conductivity: (i) a strong isotope shift of the glass transition temperature and (ii) a significant reduction of the energy barrier by zero-point quantum fluctuations. These results suggest that the high conductivity in phosphoric acids is caused by a very efficient proton transfer mechanism, which is strongly assisted by quantum effects. We propose to measure two samples: (i) 85% wt% H3PO4 in H2O, and (ii) D3PO4 in D2O between 10 and 300K.

We propose to explore the morphology of Ethylammonium Nitrate (EAN, a protic ionic liquid, PIL)-water mixtures. Both components are polar, protic compounds whose structure is hold by an Hydrogen bonding network. The mixtures are mesoscopically homogeneous, but previous studies indicate that the two components tend to maintain their chemical identity at microscopic level. This observation and recent reports indicating a complex behaviour in EAN-rich mixtures, call for exploration as a function of composition, using neutron scattering to complement our X-ray scattering and Raman spectroscopy data sets. Data will be interpreted using the EPSR approach. The understanding of the structural features of these mixtures can help in developing smart, task specific mixtures of PIL and molecular liquids for specific applications.

To date many papers have been published on the effects of impurities on the physical properties of ionic liquids (near room-temperature molten salts), however, only few studies on the interactions between ionic liquids and solutes have been performed, which are essential for the dissolution of biomass and carbon dioxide capture. Due to hygroscopic nature of ionic liquids the most common impurity is water, even for hydrophobic ones. The addition of water to ionic liquids, significantly reduces the viscosity and density, which is favourable for many processes.This application is for the allocation of beam time to study the interaction of ionic liquids with water as a function of concentration. At high water concentrations, our ionic liquid-water system becomes more complex, with interactions between the cation and water being preferred over interactions between water molecules.

The field of ionic liquids is one of the hottest topics with the number of publications still growing exponentially. This is due to the negligible vapour pressure, non-flammability, wide liquid, solubility and miscibility range of most ionic liquids. Ionic liquids have been often described as designer solvents, as properties of their ions can be changed to improve the suitability for a given process. Protonated ionic liquids are excellent proton carriers in fuel cell electrolytes, providing electrolytes of a type that are simply not available in systems in which water acts as acid or base in the proton transfer process. But, there is a lacuna in our knowledge of these compounds. Utilisation of beam time at ISIS will help us to shed light on proton behaviour processes of protonated ionic liquids.

Considerable research efforts have been devoted to polymer electrolyte membranes fuel cells. It has been recently proposed as a promising approach to replace aqueous electrolytes with protic ionic liquids (PILs). The key property of these systems, setting them apart from conventional ionic liquids, is their proton conductivity. A more thorough understanding of proton transfer mechanisms in PILs, including the determination of a relationship between local microscopic dynamics and macroscopic transport properties, is thus crucial to facilitate the design of applications. The aim of this application is to characterize the local proton transfer mechanism both in the classical and in the quantum frame in the prototype PIL ethylammonium nitrate by means of two complementary neutron scattering techniques, i.e Quasi Elastic Neutron Scattering (QENS) and Deep Inelastic Neutron Scattering (DINS).

The field of ionic liquids (ILs) is one of the ?hottest topics? with the number of publications still growing exponentially. This is due to the negligible vapour pressure, non-flammability, wide liquid, solubility and miscibility range of most ILs. ILs have been often described as ?designer solvents?, as properties of their ions can be changed to improve the suitability for a given process. The possibility of using IL mixtures has also been taken into account for variation of their properties, for instance, density or viscosity. After the pioneering suggestion that the use of IL mixtures is a way to decrease their melting points to room temperature, they were recently proposed as effective replacements for neat ILs in dye-sensitised solar cells, due to the improved transport processes. Based on acquired experience at ISIS on single ILs, we would now like to study their mixtures.