Research Projects

Efficient harnessing of clean energy, its storage, and supply to meet the growing societal demands is of paramount importance for the sustainable development. As outlined in the Sustainable Development Goal - 7 (Affordable and Clean Energy) – increase use of renewable energy and improve energy use efficiency, clean energy access, R&D, etc. is necessary for sustainable energy services. On the other hand, it is also reported that a considerable part of the world’s energy loss (23% approx.) is related to friction. All aspects of the sustainability of energy supply and reduction of energy loss have become one of the major challenges facing science and technology today. In this regard, ionic liquids (ILs), an extremely versatile functional fluid (almost)entirely made of ions, is an ideal choice. ILs have reached practically all the areas of science and technology where solvents are required. Because of its unique thermophysical properties (low vapour pressure, high thermal stability, wide electrochemical stability window), high ionic conductivity, tunable property, etc. ILs have a wide potential applications, e.g., in large scale industrial processes, battery electrolytes, pharmaceuticals, metal deposition, protein crystallisation, and in applications requiring fast switching between high- and low-friction states, i.e., automotive, aerospace, electronics and micro-robotics industries. Despite its unique properties and advantages the practical applicability of most ILs is limited by its high viscosity and disappointing mass and charge transport compared to conventional molecular solvents. Viscosity is an important property on which many industrial process designs depend for applications involving heat, momentum, or mass transfer, e.g., electrolytes in electrochemical media, supercapacitors, solar cells, or reaction media require a low viscosity for their use and thus reducing the viscosity of ILs is critical for many applications. While there has been a significant amount of research related to pure ILs, studies addressing the behavior of IL mixtures are very limited, i.e. most of the research is on binary mixtures, with only a few studies on higher-order mixtures. The formation of mixture of ILs increases its synthetic flexibility and thus improves the performance in various application. In the proposed study, we will consider a novel model of ILs mixture, where all the cations are different and share a common anion, i.e.an extreme limit of multi-component IL mixture. It is important to note that the constituents in multi-component mixture may differ in shape, size, and energy. The aspect of ion size-disparity (while keeping the other factors constant) is the main focus of the proposed work and explore its consequences. In particular, by considering primitive and Imidazolium based coarse-grained models of ILs we will explore in what way ion size-polydispersity affect the behaviour near electrified interfaces, driven structural transition, matter/charge transport behaviour, and nanotribology. One of the main objective is to investigate whether size-polydispersity, as a control parameter, can tune/reduce viscosity thereby helping mitigate the global energy wastage. While another important aspect is to explore the electrotunable friction and in particular the role of size-polydispersity and attempt to understand the underlying microscopic mechanism of friction in mixtures of room temperature ILs, and condition leading to optimum electrotunable friction. By employing molecular dynamics simulations (and theory) we will explore the proposed model size-polydisperse IL mixture.