Nanostructure of phosphonium orthoborate ionic liquids for lubrication

We have developed a class of phosphonium-orthoborate ionic liquids (ILs) with exceptional lubricative properties, both in their pure state and when mixed with a model base oil (propylene carbonate or 2-ethylhexyl laurate). These systems were studied extensively at the interface, showing significant interfacial adsorption and structuring, and concentration-dependent electroresponsivity. In this proposal, we aim to correlate these properties with the bulk nanostructure using Small-angle Neutron Scattering (SANS). ILs often have persistent domain structure in the bulk and isotopic contrast variation will be used to elucidate this. The existence of ordered domains within the IL may affect the lubricity through interactions with the adsorbed layer. We hope to observe this nanostructure to expand the depth of our interfacial studies into the bulk.