Synthesis Antifreezing and Antidehydration Organohydrogels: One-Step In-Situ Gelling versus Two-Step Solvent Displacement

Organohydrogels with distinct antifreezing and antidehydration properties have aroused great interest among researchers, and various organohydrogels and organohydrogel-based applications have emerged recently. There are two popular synthesis strategies to prepare these antifreezing and antidehydration organohydrogels: the in-situ gelling and the solvent displacement strategies. Although both strategies have been widely applied, there is a lack of comparative study of these two strategies. In this work, to elucidate the comparative advantages of the two synthesis strategies, we studied and compared the mechanical and environmental tolerant properties of the organohydrogels synthesized from both strategies. The glycerol-based and ethylene glycol-based chemical polyacrylamide (PAAm) organohydrogel and the glycerol-based physical gelatin organohydrogel were synthesized and studied. Through the comparative study, we have found that the organohydrogels from different strategies with the same dispersion medium showed similar antifreezing and antidehydration properties but different mechanical properties. The mechanical properties of these organohydrogels are influenced by two opposite factors for each strategy: the enhanced physical interactions induced strengthening and solvent effect or swelling induced weakening. We hope this study may provide a better understanding of the synthesis strategies of organohydrogels and provide a valuable guide to choose the suitable synthesis strategy for each application.