Electrorheological and dielectric behavior of new ionic liquid/silica systems

• New ionic liquid based on 11-carboxyundecyltriphenylphosphonium bromide prepared.
• New ionogels with ionic liquid confined in silica particles prepared.
• Ionic liquid/silica ionogel suspensions with improved electrorheological behavior.

New phosphonium-based ionic liquids, denoted, 11-carboxyundecyltriphenylphosphonium bromide (IL1) and octadecyltriphenylphosphonium iodide (IL2), were employed on the sol–gel synthesis to prepare new silica-based matrices. The fastest gelation during the sol–gel process was observed in hydrolysis/condensation of tetraethoxysilane in the presence of IL1. The confinement of ionic liquids (especially IL1) inside the silica networks was suggested by thermogravimetric analysis and Fourier transform infrared spectroscopy. The resulting ionogels present higher permittivity than pure silica and were used as the solid component for the development of new electrorheological fluids, presenting good ER behavior, mainly those prepared with IL1.

Figure optionsDownload high-quality image (89 K)Download as PowerPoint slide