Regulation of Phenol-Quinone Equilibrium in Metal-Polyphenolic Network for Initiating Vinyl Monomer Polymerization

In this study, gallium-based MPN was synthesized via ultrasonication of bulk gallium in an aqueous dopamine (DA) suspension. A key novelty lies in our regulation of the phenol-quinone redox equilibrium transition within MPN through a tunable proton-coupled electron transfer (PCET) pathway with coexistence of Ga NPs@PDA and external DA, which enables controlled generation of neutral o-semiquinone radicals (DA•) alongside modulated MPN size growth and colloidal stability decay. This controlled equilibrium was leveraged to develop a one-pot synthesis strategy for functional hydrogel: embedded MPN, Ga-NPs@PDA, and external DA precursors collectively induce vinyl monomer polymerization and crosslinking, yielding multi-functional hydrogels with low hysteresis, tunable pore size, and excellent adhesion. This work establishes a methodology for controlling the phenol-quinone equilibrium, elucidates the mechanisms underlying MPN self-assembly and DA• formation, advances the development of functional MPN nanomaterials, and expands their application potential in functional polymer composites—particularly through the innovative one-pot hydrogel synthesis approach enabled by the newly discovered MPN structural evolution mechanism.