IL-Silica Hybrid Materials

The entrapment of catalysts by utilizing sol-gel methodologies in order to prepare recyclable catalysts has been known since 1993 [44]. We refer to a review for more information on these systems [45]. 

In 2010, Karimi and coworkers [51] synthesized periodic mesoporous silicas with alkyl imidazolium fragments as comonomer, leading to the coating of the alkyl imidazolium fragments onto the inside pore surface of these mesoporous silicas. These mesoporous silica frameworks coated with IL fragments were used to immobilize palladium nanoparticles. 

TEOS/EtOH Ionic liquid + metal complex HCI 

Clearly, the actual way of producing an IL-modified material is often predetermined by the type of application, the type of raw materials, or other conditions determined by the application. In those cases where more than one production route is feasible to obtain equally performing materials, the overall process costs will determine the method of choice at least for commercial production. In the end, any added costs, either stemming from the cost of the IL itself or the process of applying it have to be justified by an added value for the applicant. 

Liapis, A.I. and Bruttini, R. (2007) Handbook of Industrial Drying, 3rd edn, CRC Press, Boca Raton, FL, pp. 257-283. 

---

Water, however, modifies the patterns of self-organization, and this is why the structural outcome of such reactions depends greatly on the water content. The peculiar self-aggregation behavior of the IL/water system is seen by comparing two sol-gel derived IL-silica hybrid materials (using lu), prepared with varying amounts of water (Fig. 6.3-4), but the same ratio of IL to silica. 

---