Polymerization-Induced Self-Assembly Toward Micelle-Crosslinked Tough and Ultrastretchable Hydrogels

Abstract

As a promising class of tough and ultrastretchable hydrogels, micellecrosslinked hydrogels have been restrained by the scarcity of micellar crosslinkers with a high concentration, controlled nanostructure, and uniform size distribution. Herein, polymerization-induced self-assembly (PISA) was demonstrated to be a general and powerful platform for micellar crosslinkers, affording micelle-crosslinked hydrogels with tailorable chemical structures, mechanics, and functionality. Poly(N,N-dimethylacrylamide)-b-poly(diacetone acrylamide) (PDMAc-b-PDAAM) micellar crosslinkers with a controlled nanostructure and uniform size distribution were prepared via PISA and onestep post-polymerization modification at high concentrations. Copolymerization of these micellar crosslinkers with acrylamide generated tough and ultrastretchable hydrogels, whose mechanical properties were found correlated with the concentration, nanostructure, and chemical composition of the micelles. The energy dissipation mechanism of these micelle-crosslinked hydrogels was analyzed via cyclic mechanical tests and stress relaxation experiments. The general feasibility of PISA toward micelle-crosslinked hydrogels was verified by systematic evaluation of both aqueous (including 2-methoxyethyl acrylate, tetrahydro-2-furanylmethyl acrylate, and 4-hydroxybutyl acrylate) and alcoholic (including benzyl methacrylate, lauryl methacrylate, styrene, and benzyl acrylate) PISA formulations, producing hydrogels with diverse chemical structures, mechanics, and functionalities depending on the micellar crosslinkers. The modularity of this strategy was further demonstrated by the fabrication of fluoro-functionalized hydrogels with fluoro-containing micellar crosslinkers. This strategy has significantly enlarged the scope and application of micelle-crosslinked hydrogels.

Strong and Tough Nanostructured Hydrogels and Organogels Prepared by Polymerization‐Induced Self‐Assembly

“…Further prolonging the waiting time does not improve the recovery ratio, which resembles the energy dissipation in the micelle‐crosslinked hydrogels. [ 26 ] Therefore, we deduce that the energy is dissipated by the reversible deformation of micelles when ε < ε c . When ε > ε c , both the reversible deformation of the micelles and the irreversible detachment of the constituting polymers from micellar cores contribute to the energy dissipation, whereas the latter results in plastic deformation due to the slow relaxation kinetics of polymeric micelles.…”

Aligned Porous and Anisotropic Nanocomposite Hydrogel with High Mechanical Strength and Superior Puncture Resistance by Reactive Freeze-Casting

“…It can be seen from Figure S19 (Supporting Information) that at the beginning both directions produce significant stress relaxation, which may be due to the partial hydrogen bond dissociations in the system. After 3 h, the stress of the Parallel is still greater than half of the maximum stress and the Parallel can still maintain high stress under long-term loads, thanks to the strong cross-linking in the orientation direction, indicating the high resistibility against static fatigue damage. , …”

Highly stretchable, self-adhesive, ambient-stable, and wide-temperature adaptable hydrophobic ionogels for wearable strain sensors

“…Due to the unique structures with flexible crosslinking centers compared with the rigid crosslinking centers of small molecules, crosslinking based on polymer micelles, microspheres, and some macromolecules has been used to prepare highly stretchable gels with excellent fatigue resistance and low hysteresis. [46][47][48][49] More importantly, crosslinking with multifunctional macromolecular crosslinkers can not only lead to a reduced inhomogeneity of the gel network, but can also significantly improve both the mechanical strength and the toughness of the gels compared with the ordinary gel crosslinked with the conventional crosslinker. 50 Therefore, it would be prudent to introduce macromolecular crosslinkers to a double-network or dual-crosslinked network to develop new network ionogels with excellent stretchability and mechanical stability/durability.…”