Supplementary material from "Ionic Liquid Gels: Catalysts for Sustainability in Synthesis, Energy, Electronics and Medicine."

This opinion paper reflects upon highlights in ionic liquid gel research for green and sustainable chemistry. Discussed are some key observations from research into ionic liquid gels in catalysis, and insights into potential future uses and areas for development. It is noted that some IL gels have a remarkable ability to hold onto precious metals when used to entrap catalysts (nanoparticulate metals and complexes with minimal leaching) allowing heterogenized homogeneous catalysts to be reused, recycled and easily separated. Herein we present observations that ionic liquid gels can actively absorb and retain metals from solution. Evolving trends in research into liquids comprised of ions will be reviewed and a future in which the ionic liquid gels themselves are green and sustainable materials is hypothesized, which will accelerate their adoption as NaturIL gels in synthesis, materials, electronics and medicine.