Effect of Fumed Silica on Ion Conduction in Proton-Conducting Nanocomposites

In this work, a series of nanocomposites using polymerized ionic liquid (PolyIL), protic ionic liquids (PILs), and nanosilica were developed. The influence of nanosilica on the physical properties of nanocomposites was studied. The binary PIL/silica composites showed decreased ionic conductivity with the addition of silica. However, in the presence of the polymer, the binary PolyIL/silica and ternary PolyIL/PIL/silica showed increased ionic conductivity with a small amount of silica, resulting from the interactions between silica and the anionic groups of PolyIL. This work demonstrated that while adding silica is unfavorable for ionic liquids, it has the potential to promote ionic conductivity in polymer composites.