Structured Ionic Liquids for Functional Products

1033878 Alexandridis Background & Motivation Ionic liquids (ILs), organic salts that are fluid at ambient conditions, are a novel class of compounds with a combinatorially great molecular diversity and unique properties. The very low volatility and high thermal and chemical stability that many ILs exhibit, render them promising as solvents. Underscoring the successes of ILs as reaction media and in dissolving the otherwise insoluble cellulose and carbon nanotubes, are the multiple intermolecular interactions that ILs afford. The broad goal is the development of fundamental knowledge to support and guide the next generation applications of ionic liquids in formulated chemicals or functional products, i.e., multi component systems that are rationally designed to meet specific end use requirements. Internal structure over multiple length scales is important in all functional products. ILs are uniquely suited to facilitate structuring on the basis of the short and long range interactions inherent in their chemistry. In addition to structure, mobility is an important consideration in IL containing products. Statement of Objectives The investigators base the proposed research on the premise that fundamental understanding of interactions of ionic liquids with molecular solvents, amphiphiles, polymers, proteins, and nanoparticles is an enabling stage toward the rational formulation and structure property optimization of ionic liquid-based complex fluids, soft materials, nanomaterials, and hybrids, as well as consumer products and devices that incorporate the above materials. Multiple interactions, often subtle, act in tandem in such multi component systems, but their manifestation in system properties can be profound. To this end, the investigators aim to (i) establish operating intermolecular interactions in binary IL-amphiphile systems as reflected in structure and dynamics, (ii) pursue synergisms by characterizing molecular organization in multi component systems consisting of ILs, molecular solvents, amphiphiles, and polymers, and (iii) assess IL-amphiphile blends for their ability to accommodate salts or nanoparticles, thus facilitating the advancement to formulated products. Having real life applications in mind, the investigators will tailor our efforts to ionic liquid-polymer systems that are relevant as electrolytes in lithium batteries, and to IL-nanoparticle systems for dye-sensitized solar cells. Intellectual Merit: The proposed research will enhance the fundamental understanding of ionic liquid + nanoparticle hybrid systems, where nanoparticle is used here broadly to encompass materials that are hard/inorganic or soft/organic, macromolecular or supramolecular, natural or synthetic. The integration of this knowledge into the rational design and development of IL-based products could have a potentially transformative effect in what is currently a nascent activity. Other novel aspects include the characterization of blends of ionic liquids, of IL + solvent mixtures and of IL + nanoparticle dispersions with respect to their structuring ability and dynamics. Also, the comparison of IL + amphiphile systems and molecular solvent + amphiphile systems. Broader Impacts: This research will have a positive and timely impact on efforts directed toward the development and commercialization of batteries, fuel cells and solar cells that incorporate ILs. Information on interactions between ionic liquids and water, organic solvents, (bio)surfactants and/or (bio)polymers will prove valuable in assessing the impact of ILs on human health and their fate in the environment. The findings should also be beneficial to the analytical chemistry applications of ILs. This project will integrate research and education by incorporating lectures and projects related to ionic liquids, structuring and functional products in the various courses that the PI teaches at both the undergraduate and graduate levels. The PI together with undergraduate students will develop and offer outreach activities geared toward high school and 1st year college students.