Co-assembly of Polyoxometalates and Zwitterionic Amphiphiles into Supramolecular Hydrogels: From Crystalline Fibrillar to Amorphous Micellar Networks.

Gelation mechanism is of utmost importance to the rational design of supramolecular hydrogelators. Although both kinetic and thermodynamic controlled self-assembly processes have been widely studied in hydrogels, the formation relationship between crystalline and amorphous gel networks still remains ambiguous. Herein, a gelation transformation from a kinetic to a thermodynamic process was achieved by balancing the rigidity and flexibility of the inorganic-organic co-assemblies. By using polyoxometalates and zwitterionic amphiphiles, the transition morphologies between crystalline and amorphous hydrogel networks were evidenced for the first time, as ordered wormlike micelles. Given the versatile applications of hydrogels in biological systems and materials science, these findings may highlight the potential of inorganic-organic binary supramolecular hydrogelators and fill in the blank between kinetic and thermodynamic controlled gelation processes.