Silica ionogels and ionosilicas
Résumé
This chapter provides an overview of the recent developments in the preparation of silica ionogels and ionosilicas and of the applications of these materials derived from ionic liquids (ILs) or inspired by them in some topical fields as electrochemical and optical devices, environmental sustainability, and pharmaceuticals. Besides applications in catalysis, ionosilicas offer great opportunities in the fields of separation and molecular recognition. The chapter emphasizes that ionosilicas should be considered as a distinct family in the area of silica hybrid materials. Surface-functionalized ionosilicas are generally synthesized either via postsynthesis grafting or hydrolysis–cocondensation reactions involving trialkoxysilylated ionic precursors. The chapter illustrates the two different synthetic methods involving a monosilylated imidazolium precursor 3-methyl-1-(3-(triethoxysilyl) propyl)-imidazolium chloride. Cocondensation reactions involving ionic compounds are of particular interest in soft templating approaches to nanostructured ionosilicas as the ionic nature of the precursor offers the possibility to induce modified precursor–surfactant interactions.