Effect of temperature on soft glassy behaviour of silica-ionic liquid nanocomposite

Abstract

We prepared nanocomposites of silica-ionic liquid with varying composition of silica nanoparticles (mean diameter d =14 nm) in 1-Ethyl-3-methyl bis (trifluromethanesulfonyl) imide (Emim TFSI) ionic liquid. Dynamic rheological measurements have revealed soft glassy nature of these nanocomposites at room temperature. Quite surprisingly, the nanocomposite is found to behave as a strong gel rather than melting into a viscoelastic liquid upon increasing the temperature. A qualitative explanation for the observed behaviour is provided based on the networks of aggregates of silica nanoparticles in ionic liquid and their evolution with respect to temperature. © 2011 IEEE.