Effects of Nucleophilic Catalysts on the Self-Assembly of Hydrazone-Based Supramolecular Hydrogels

Catalytic control over molecular self-assembly provides a powerful approach to regulate the structures as well as the functionalities of supramolecular materials. Revealing how the catalysts affect the molecular self-assembly process is crucial for rational design and control of the supramolecular self-assembly systems. Herein, relying on a hydrazone-based dynamic supramolecular hydrogel system, the effects of various nucleophilic catalysts on the self-assembly of the hydrogels are investigated, demonstrating that the catalyst influences the hydrogelators self-assembly via facilitating both the reaction and hydrogelators nucleation processes. The catalyst with higher catalytic activity accelerates the formation thereon the self-assembly of hydrazone-based hydrogelators, leading to hydrogels with more branched networks and higher stiffness. Importantly, we also verify that the catalysts, depending on the molecular structure, can also accelerate the self-assembly process by affecting the hydrogelators nucleation process. These findings not only add more details to the effects of nucleophilic catalysts on the hydrazone-based hydrogelation system, but also suggest that both the catalysis activity and chemical structures should be considered for catalytically controlled molecular self-assembly. Nucleophilic catalysts accelerate the self-assembly of hydrazone-based supramolecular hydrogels not merely through influencing formation of hydrogelators but also accelerating nucleation of hydrogelators. The addition of different nucleophilic catalysts leads to different network morphologies and stiffness of supramolecular hydrogels, providing a catalytic handle to control the self-assembly of hydrazone-based supramolecular hydrogels. image