Blood Clotting-Based Design of Micelle Hydrogels Via Polymerization-Induced Multivalent Hydrogen Bond Interaction

Mammals can rapidly form shear-resistant blood clots to plug vascular damage by gluing blood cells together. Inspired by the mechanism of blood clotting, we proposed the use of polymerization-induced multivalent interactions as a general strategy for preparing colloidal hydrogels comprising strongly bonded soft micellar particles with high stretchability and toughness. Specifically, poly(methacrylic acid)-b-poly(isobornyl acrylate) spherical micelles were prepared and mixed with acrylamide, which formed monovalent hydrogen bonds with the corona of the micelles. The in situ polymerization of acrylamide yielded polyacrylamide (PAM), which formed multivalent hydrogen bonds with the micellar corona physically cross-linking the micelles to form a micelle hydrogel. The formation of the hydrogel was confirmed by the in situ attenuated total reflectance Fourier-transform infrared spectroscopy. The mechanical properties of the micelle hydrogel were tunable by varying the concentration of the hydrogen-bonding monomer, micelles, and the nanostructure of micelles. The universality of this strategy was demonstrated by designing various micelle hydrogels using different types of micelles and hydrogen-bonding monomers. The micelle hydrogel was demonstrated to be a potential flexible strain sensor owing to its high stretchability and toughness. This study provides new insights into the design of colloidal hydrogels based on soft particles.