fig4

Figure 4. Schematic illustrating the gel preparation methods. For hydrogels: (A) physical crosslinking; (B) chemical crosslinking; (C) ionizing radiation crosslinking. For ionogels: (D) in-situ reactions in ILs; (E) solvent exchange; (F) direct polymerization of polymerizable ILs. For aerogels: (G) sol-gel and drying method.